IRREGULARITIES OF THE TEETH, AND THEIR TREATMENT. IRREGULARITIES OF THE TEETH, AND THEIR TREATMENT. BY EUGENE S. TALBOT, M.D., D.D.S., PROFESSOR OF DENTAL SURGERY IN THE WOMAN'S MEDICAL COLLEGE; LECTURER ON DENTAL PATHOLOGY AND SURGERY IN RUSH MEDICAL COLLEGE, CHICAGO. WITH 152 ILLUSTRATIONS. PHILADELPHIA: P. BLAKISTON, SON & CO., 1012 WALNUT STREET. 1888. Kntcrrd iut-onling to Act of Congress, in the year 1887, by EUGENE S. TALBOT, In tht- Office of the Librarian of Congress, at Washington, D. C. TO MY TEACHER AND FRIEND, WALTER S. HAINES, M.D., PROFESSOR OF CHEMISTRY, RUSH MEDICAL COLLEGE, CHICAGO, THIS VOLUME IS RESPECTFULLY DEDICATED. PREFACE. In presenting to the profession a work upon the irregu- larities of the teeth, the author has endeavored to keep in view the marked progress that has been made in this department of dental science within the past few years. This ERRATA. Page 157." Dr. Magill's Retainer" should read, "Dr. Guilford's Retainer." Cuts Nos. 6, 19, 49 and 50 should be credited to Dr. John J. R. Patrick, Illinois State Dental Society Transactions of 1884. In that portion of the work devoted to descriptive anatomy and to physiology, attention is given to those tissues only that are immediately involved in the study and correction of irreg- ularities. Each subject is considered in the order in which it would naturally present itself to the mind of the operator while the patient is before him, this clinical character being deemed by far the best for a work of this kind. In the treat- ment of irregularities, mechanical laws are illustrated and applied in the simplest manner possible, each law being applied practically to a case of irregularity; this method vii PREFACE. In presenting to the profession a work upon the irregu- larities of the teeth, the author has endeavored to keep in view the marked progress that has been made in this department of dental science within the past few years. This treatise is intended to embrace all that is necessary to a clear and practical understanding of the etiology and treatment of dental irregularities. Our knowledge of the etiology of the various deformities of the teeth has hardly kept pace with the marked advancement in the methods for their correction, and this fact has induced the author to devote considerable attention to the causes of such con- ditions, while due consideration has been given to the methods of treatment. No pretense has been made to cyclopa3dic fulness, inasmuch as it is believed that practi- cableness and conciseness in a scientific work are preferred by the profession to verbosity and minuteness of detail. In that portion of the work devoted to descriptive anatomy and to physiology, attention is given to those tissues only that are immediately involved in the study and correction of irreg- ularities. Each subject is considered in the order in which it would naturally present itself to the mind of the operator while the patient is before him, this clinical character being deemed by far the best for a work of this kind. In the treat- ment of irregularities, mechanical laws are illustrated and applied in the simplest manner possible, each law being applied practically to a case of irregularity; this method vii ,-KKFACE. being apparentlv th, htt t impn* the principal fea u^ . heoU' UMotorimgulwitouponthemmdofthe . It would 1* obviously impossible, as well u UK U , illu-t: |N"iti"n in which a wedge, scivw. level or .* nmv In- applunl ; but the author has endeavored np^al, illustration, u pri.u^.le or lau that tin- siu.li.nl will be able to exemplify each principle in a varidy of vq - Although a delicate subject, tin matter of fees ia necessarily a term /V"//'"'/" to th- student, ami aa .MK-lirvnl by tin- author tlH':i matter of greal import- ana- to In.th juitinit ami oj>erator. Tlu> author has endeavored to give due <-ivdit to th.-.- workrrs in tli.- tit'M f orthi.lontia that havt- contril.utcd t.. t> advaiKviiu-nt, and if any injusticr has b.vii doiu- it has been uninu-ntional. Tin- author desires to acknowledge :ndrbt.-diu-*s to hr>. tions, and aN., to th,- S. S. Whitr IVntal Manufacturing Company tor the u-e of many \\.MM!, utv Ki-.. s - TALBOT. - Dem>'- e, 17 CONTENTS. PART I. ANATOMY. CHAPTER I. PAGE THE SUPERIOR MAXILLJE, 9 THE INFERIOR MAXILLA, 14 THE SUPERIOR ALVEOLAR PROCESS, 17 THE INFERIOR ALVEOLAR PROCESS, 18 ANATOMY AND PHYSIOLOGY OF THE TEETH, 20 DESCRIPTION OF THE TEETH, 21 THE TEMPORARY TEETH, 25 CHAPTEE II. OCCLUSION OF THE TEETH, 27 THE CROWNS AND BOOTS, 29 TEETH IN POSITION IN THE MAXILLA, 29 CHAPTER III. ETIOLOGY OF IRREGULARITIES, IRREGULARITIES OF THE TEMPORARY TEETH, . . IRREGULARITIES IN THE SIZE OF THE PERMANENT TKKTH. . . . IRREGULARITIES IN THE NUMBER OF THE PERMANENT TKKTH. , IRREGULARITIES IN THE ARRANGEMENT OF THE PERMANENT "ti TEETH, CHAPTER IV. 40 ACQUIRED IRREGULARITIES, . THE CENTRAL INCISORS, THE LATERAL INCISORS, THE CUSPID TEETH, ix COM I N '- 46 K-BMnr W IW BEI-vnov- ro UBEnf LAIMI 'IK SSSSLmi^Tl*- I \KITtE*. . .">! THE V^HAPED AK. M ; n BABM u > i- ' ^ v ' ' " ....... . . . ^i-i> uv I 'Ho I ' >N< 1 I ' I'!' 1 V I 1"N "r in'- IBB* 58 TKMIHIBABY TEETH (HAPTl-i: \. i ic \i HUN up mi: TKM- roBABY TEETH ^ gg |H,lTKrHIOXOF TIIK Cl'TKU .1 V\\'. rumw-- " : UVN - I ^ iBBEUt UABITIK* <>K THE TEETH "I PART II. TREATMENT. ( HA1TKR I. THE Ptorm PKMOD FOB RBOI-LATIXO IHY-1 v\|. I'MllMl.H.H \l ClIANCiKS, ""' KTIIETECTII : ~ DKCAY or THE TEETH OCCLCWOV < HAITF.l; II. -i, iOXH OF THE M"i III. AM'M"litl> ............. 82 ftrt-iiY or TH* MODELS, .................. ... 88 ArrucATiox 01 i ................... 93 I-HAITKI; in. Mia n i: KS 97 THE I.rv-EB. 97 99 THE IN- i INH- PI \\> 100 THE STBEW ... 101 CONTENTS. THE WEDGE, .......... ELASTIC FORCE, .......... LIGATUEES, .............. ELASTICITY OF METALS, ........ CHAPTER IV. CONSIDERATION OF THE DIFFERENT METHODS, ... 1 13 PATRICK'S METHOD, FARRAR'S " BYRNES' ' 116 COFFIN'S j2i AUTHOR'S . ]. )(i PIANO-WIRE, .125 SPREADING THE DENTAL ARCH, 12g REGULATING INDIVIDUAL TEETH, CHAPTER V. TREATMENT OF SPECIAL FORMS OF IRREGULARITIES, 135 ROTATING TEETH IN THEIR SOCKETS, 135 THE FARRAR METHOD, 135 GUILFORD'S " 138 THE AUTHOR'S " 139 MOVING CROWNS AND ROOTS, 140 FORCED ERUPTION OF THE TEETH, 1 !.' THE MATTESON METHOD, 142 THE AUTHOR'S " 143 CHAPTER VI. PROTRUDING TEETH, KINGSLEY'S, J " " FARRAR'S, PROTRUSION OF THE INFERIOR MAXILLA, ALLAN'S CASE, ] METHODS OF RETENTION OF THE TEETH AFTER REGULATING KINGSLEY'S RETAINERS, RICHARDSON'S " RUBBER PLATES WITH GOLD BANDS AND BARS, FARRAR'S RETAINERS, MAGILL'S THE AUTHOR'S " I OF TIME REQUIRED TO RETAIN THK TEKTII ix I'i. \art of the PART I ANATOMY. 11 orbit. Commencing near the middle of the outer border of this surface, and passing forward, is the infra-orbital groove terminating in a canal, which subdivides into two branches' the infra-orbital, opening just below the margin of the orl.it' and the anterior dental canal, which runs into the anterior wall of the antrum and transmits the anterior dental vessels and nerves. The inferior oblique muscle of the eye arises from the anterior and internal part of the surface (Fig. 2). FIG. 2. BONES PARTIALLY CLOSING OR/f/CE Of ANTRUM MARKED IN OUTLINE ANTER. NASAL SPINE BRISTLE PASSCO THROUGH ANTE. PALAT. CANAl INTERNAL SURFACE. The internal surface forms a part of the cavity of the mouth and a part of the outer wall of the nose, the two parts being separated by the palatal process. The superior division pw sents the opening leading into the antrum of Highmmv. the upper border of this opening are several irwgolai . ties closed in by the ethmoid and lachrymal bones mencing near the middle of the posterior border of \-> IRREGULARITIES OF THE TEETH. and running downward and forward, is a groove, om- 1 im,, u canal (the posterior palatine) by the articulation of thi> jH.rtion of the bone with the vertical plate of tin- pal- ate. Itclow the opening is a concavity forming a part of the inferior im-atu* f tin- nose. It is traversed by the maxillary li-iirc. whi.-li receives the maxillary process of the palate A deep groove, converted into a canal by the articu- lation of the lachrymal and inferior turbinated bones i- Bit- uated in front of the opening of the ant rum. It is called the lachrymal or nasal duct. Anterior to this is the inferior tur- l.inat.' which articulates with the inferior turbinated IK.HC. Above this crest is a part of the middle nn-atus. and In-low it a part of the inferior mcatus of the nose. The infe- rior division of this surface i< rough, and has several small opening- for the passage of nutrient vessels. The antrum of Highmore is a triangular-shaped cavity, funded by the four surfaces of the body of the bone and by the alveolar process, and with its base toward the internal surface. ( >n the latter surface is the irregular opening of the antrum. which is nearly closed in the articulated >kull by the approximation of the ethmoid, inferior turbinated and palate b<.; On the posterior wall of the antrum are the posterior dental canals, and on its floor are seen several conical pro- u<. corn-ponding to the roots of the molar teeth. The Malar Process is a rough eminence situated at tin junction of the facial and zygoma tic surfaces. It is concave in front and behind, articulates above the malar bone, and below is marked by a ridge which separates the facial from the /ygomatic Mirface. The Xasal Process is situated at the >ide of the nose and extends upward, inward and hack- ward. Its external surface is smooth and concave, and gives attachment to the levator labii .superioris ala^ne nasi. the orbicularis palpchrarum and tendo-oeuli nuiM-les. and is jK-rforated by several foramina. The internal surface articu- lates above with the frontal, and has a rough surface, which closes in the anterior ethmoid cells; below this are seen, from PART I ANATOMY. 13 above downward, the following points of interest : the supe- rior turbinated crest, a part of the middle meatus of the nose, the inferior turbinated crest, and a part of the inferior meatus. The anterior border is directed obliquely downward and forward, and articulates with the nasal bone ; the posterior border presents a groove for the lachrymal duct, and has two margins, the inner articulating with the lachrymal bone, and the outer forming a part of the circumference of the orbit. The Palatal Process projects inward from the internal surface of the bone. It is a strong process, thicker in front than behind, and forms a large part of the roof of the mouth and of the floor of the nose. Its upper surface, smooth and conical, presents in front the upper orifice of the anterior palatine canal, situated just behind the incisor teeth and transmitting the anterior palatine vessels. The naso-palatine nerves pass through the inter-maxillary suture. The inferior surface, rough and uneven, is perforated by numerous foramina for .the passage of nutrient vessels. At the back part, near the alveolar border, is a longitudinal groove (sometimes a canal), which transmits the posterior palatine vessels and large nerves. The lower orifice of the anterior palatine canal may be seen on this surface. In some bones may be seen a delicate suture, which marks out the inter-maxillary bone ; this comprises that portion of the upper jaw which contains the incisor teeth. The outer border of this process unites with the body of the bone- The inner border unites with the bone of the opposite side, and the two form a groove on the upper surface for the reception of the vomer. The anterior border is prolonged forward internally to form the anterior nasal spine. The posterior border articulates with the horizontal plate of the palate bone. 14 I U REGULARITIES OF THE TEETH. TMI-: iM'i:i;ioi; MAXILLA. Tin- inferior maxillary bone (Fig. 3) consists of a body and two mini. The body is horizontal, and curved like a horse- shoe, and presents for examination two surfaces and two borders. The external surface, convex from side to side, j .r< - M-nis in its median line a vertical ridge, the symph\ which indicates tin- junction of the two pieces of which tin- bom- consists in early life; this ridge terminates below in an eminence the mental process. Just external to the sym- physis. ami below the incisor teeth, is the incisive fossa, for Fio. 8. M'O*. the attacbnit-nt of the levator menti muscle. Kxtcrnul to this, and just below the second bicuspid tooth, is the menial foramen, through which pass the mental nerves and artery. Extending outward from the base of the mental pro- the external oblique line, at first nearly horizontal, bul after- ward inclining upward and backward. It is continuous with the anterior border of the minus, and affords attachment to the depiv urfai behind this groove. The inferior dental canal runs downward and forward, in the suhstance of the bone, as far as the incisor teeth, when it turns to communicate with the mental foramen ; it contains the inferior dental vessels and nerves. The lower border of the ramus is continuous with the body of the bone. The junction of the inferior and posterior hol- ders of the ramus forms the angle of the jaw; it is marked l>y rough ridges on both sides, the masseter muscle being attached externally, the internal pterygoid internally, and the stylo-maxillary ligament between the two mii-des. The anterior border is continuous with the external oblique line. The posterior border is thickened, rounded and covered hv the parotid gland. The superior border presents two processes, an anterior or coronoid and a posterior or condyloid. The coronoid pro- cess is a thin, triangular eminence of bone, which gives attachment on either side to the temporal muscle. On the internal surface is the commencement of a ridge which extends to the posterior part of the alveolar process. On tin outer side of this ridge is a deep groove, wlii eh. with the rid. rives attachment above to the temporal and below to the buccinator muscle. The condyloid process consists of two portions, the condyle PART I ANATOMY. 17 and neck. The long axis of the condyle is transverse, and the outer extremity is a little higher than the inner. It is oblong in form, the articular surface extending farther On the posterior than on the inferior surface. The neck presents externally a tubercle for the attachment of the external lat- eral ligament. The anterior surface is concave, and has attached to it the external pterygoid muscle. The posterior surface is curved. THE SUPERIOR ALVEOLAR PROCESS. The alveolar processes comprise the larger part of the lower borders of the superior maxilla? and the upper border of the inferior maxilla. The alveolar process of each supe- rior maxilla includes the tuberosity, and extends as far forward as the median line of the bone, when it articulates with the process upon the opposite side. It is narrow in front, and gradually enlarges until it reaches the tuber- osity, where it becomes rounded upon itself. If we examine the two articulated superior maxillary bones (Fig. 5), we see that the anterior part is curved, while the posterior part gradually diverges from the central line of ossifi- cation of the maxillary bones. The shape varies in different individuals. Some arches are small and others large ; the arch is parabolic in some cases and circular in others. The process is composed of two plates of bones, an outer and an inner, which are united at intervals by septa of can- cellous tissue. These form the alveoli for the reception of the roots of the teeth. The outer plate is thinner than the inner. In some cases the buccal surfaces of the roots of healthy teeth extend nearly or quite through the outer bony plate. 18 IRREGULARITIES OP THE TEETH. This plate is continuous with the facial and zygomatic -urfaces of the maxillary bone. The inner plate is thicker and stronger than the outer, and is fortified by the palate 1 Mines. The external plate is irregular upon the outer surface, prominent over the roots of the teeth, and depre--ed between the roots or interspaces. The prominence over the canine teeth, called the canine eminence, is very marked, and decidedly modifies the expression of the face. The sockets of the central incisors are conical and round, those of the lateral incisors conical and slightly flattened upon their mesial and distal snrt'a and not so large as the central sockets. The pit for the cuspid is conical and much larger than any of the other sockets. The sockets for the bicuspids are flattened upon their anterior and posterior surfaces, and near the apex they are frequently bifurcated. The socl of the molars are large at the openings, but at about the middle of their length they are divided into three smaller sockets for the reception of the roots. In the ease of the third molar the number of sockets ranges from one 1. cavity to three or four of smaller size. THE INFERIOR ALVEOLAR PROCESS. The alveolar process of the inferior maxilla extends from the ramus of one side to the same point on the other. The outline is similar to that of the superior process, the anterior portion being much thinner. The description given of the structure of the superior pro- cess will also apply to the inferior. The outer plate of hone opposite to the molars and bicuspids is thicker than the inner plate, while the inner plate opposite the canines and incisors is thicker than the outer. The alveoli are arranged along the border of the hoi. the reception of the roots of the teeth. They correspond in form to the roots which they accommodate. The alveoli lor the central incisors are smaller than those for the lateral. They are conical in shape, and flattened upon their mesial PART I ANATOMY. 19 and distal surfaces. Those for the lateral incisors are larger, and compressed on their mesial and distal surfaces. The sockets for the canines (cuspids, or stomach teeth) are larger, deeper and less compressed than those for the incisors. The sockets of the bicuspids are considerably flattened upon their lateral surfaces, and are sometimes divided into two cavities. The sockets for the anterior roots of the molars are broad and flattened laterally, while those for the anterior roots are round. The third molar, being naturally of variable form, has sometimes one pit, and again three or four. Each alveolar pit or socket is divided from its FIG. 6. neighbor by a small wall or septum, which is made up of cancellated bone, extending about one-eighth of an inch above the inner and outer plate. The dental septa assist in keeping the teeth firmly in their places. Fig. 6 illustrates an internal, lateral section of the lower jaw, showing the relation of the alveoli and the septa a, a, a, dental septa b, b, b, dental root septa. It will be observed that the septa are very thin at the margin, and gradually increase in width to the middle of the jaw, where they 20 IRREGULARITIES OF THE TEETH. l.ecomc thicker, and are finally lost in the substance of the jaw. Some septa are thicker than others, and where two teeth an- \\ idely separated, the width of the septa nat- ural lv corresponds to the space between the teeth. The sockets an- lined with a thin plate of compact bony substance, extending from the outer and inner plate of the alveolar process to the apex, where there are small opening for the entrance of nerve and blood vessels for the nourish- ment of the teeth. This bony plate has upon its inner surface the ela-tie peridental nieinl.rane, which acts as a cushion for the teeth. while upon the inner surface it is surrounded by .-p"ii.i:y bone. \\ATOMY AND PHYSIOLOGY OF THE TEETH The Teeth are classified as temporary and permanent. The former term is applied to those erupted in infancy. which are small and delicate, to meet the requirements of the child. The permanent teeth are of a larger and stronger growth, to meet the demands of adult age. The Temporary, deciduous or milk set consists of twenty teeth, ten in each maxilla, viz.: two central incisors, two lateral incisors, two cuspids and four molars. The Second or permanent teeth number 32, sixteen in each maxilla, viz.: two central incisors, two lateral incisor-. two cuspids, four bicuspids and six molars. For convenience of description a tooth is divided into a crown that part which is exposed in the mouth a root or roots, situated in the alveolar process, and a neck, the part connecting the crown witli the root. It is also divided, according to the tissues of which it is composed, into the enamel, dentine, cementuin, and pulp. The Enamel (Fig. 7, A) is the hardest structure of the human body. It forms a smooth, dense, external layer on the teeth, and serves as a cap or covering to preserve tin- dentine of the crown; it is thickest at the cutting and grinding edges of the tooth, and gradually diminishes in thickness until it reaches the neck, where it disappears. PART I ANATOMY. 21 FIG. 7. It is nearly inorganic in structure, containing but from one to three per cent, of animal matter. The Dentine (B), which constitutes the largest part of the tooth and gives it its shape, is an ivory-like substance composed of tubuli surrounding a cavity called the pulp chamber. The dentine is in many cases very sen- sitive. Its surface is entirely covered by enamel and cementum. The latter forms the osseous covering of the root portion of the dentine, being thickest at the apex and gradually thinning out toward the neck of the tooth (c). It is a bony substance, receiving its nourishment through the peridental membrane, which latter also nourishes the dentine through the struc- ture of the cementum. Occupying the chamber in the crown, and the canals in each of the roots of the teeth, is the pulp (D), consisting of a mucoid, gelatinous mass permeated by blood-vessels and nerves, which nourish the dentine. The peridental mem- brane covers the root of the tooth, and together with the periosteum forms a cushion between the alveolar process and the root of the tooth, thus preventing irritation to the parts during mastication. It is very vascular, and sends numerous blood-vessels into the cementum for the nourish- ment of the tooth. DESCRIPTION OF THE TEETH. For convenience of reference the different surfaces of the crowns of the teeth are designated as follows : 1st. The labial, signifying the surface nearest the lips. (This applies only to the six anterior teeth.) 2d. The buccal, the part nearest the cheek and the buccinator muscle. 22 IRREGULARITIES OF THE TEETH. 3d. The palatine, tin- surface of the upper teeth next to the hard palate. 1th. The lingual, or that part of the lower tooth nearest the tongue. ~>t\\. The anterior and posterior in the bicuspids and molars, the mesial and distal surfaces in the case of tin- six anterior teeth. 6th. The cutting edges of the incisors and cuspids and the grinding surfaces of the bicuspids and molars. The incisors (Fig. 8, Nos. 1 and 2) are so called from tl ie La t i n word iitcido (to cut), their sharp edges fitting them for cutting off such portions of food as may be required for mastication. They act on the same principle as a pair of shears. They are classed as Central and Lateral, the central inci-ors the larger. Both are concave on their lingual surfaces and convex on their labial : they are broader at the cutting edge than at the neck. The Left central is distinguished from the right by the mesial angle being a right angle, while the distal angle is slightly rounded. The root, when normal, is straight, round and conical. Occasionally it is slightly flattened upon its mesial and distal surfaces, and is frequently bent at the end, the apex being directed toward the lateral. The roots of the laterals are shorter, and have about two-third- the diameter of the ceim-als. The Canine teeth (Fig. 8, No. 3), or eu-pids. are so called PART I ANATOMY. 23 from the Latin cuspis (a spear), because they terminate in a point adapted to the purpose of seizing and tearing flesh. They are convex upon the labial surface and slightly con- cave upon the lingual. The canines of the opposite sides are distinguished by the mesial angles being shorter than the distal, thus directing the tooth toward the median line. Each cuspid tooth has a single conical root, sometimes round and sometimes flattened, always larger than the roots of the other teeth and occasionally bent and inclined toward the posterior tooth. The Bicuspids (Fig. 8, Nos. 4 and 5) are so called from their peculiar shape (bis, two, and cuspis, a spear). The two- spear or bicuspid teeth are known as the first and second bicuspids. The crowns are rounded, and a groove through the centre divides the grinding surface into two cusps, the outer being the longer. The angles differ in length, the anterior being shorter than the posterior, thus indicating the side of the mesial line to which the tooth belongs. Their roots are flattened upon the anterior and posterior surfaces, and frequently there is but one root, with a groove extending its entire length. Owing to the close resemblance between the crowns of the first and second bicuspids, it is difficult to distinguish them except in the mouth. The Molars (Fig. 8, Nos. 6, 7 and 8) (from moleri, to grind) are three in number, viz. : first, second and third. The crowns are cuboidal in shape, with from three to five tuber- cles or cusps, separated by grooves. The crown of the first molar is the largest. The upper molars have three roots, one upon the inner surface, called the palatine root, which is conical in shape, very long and round, and two upon the buccal surface, an anterior and posterior. The anterior buccal root is flattened upon the anterior and posterior sur- faces, and is larger than the posterior. The roots diverge, the palatine being the less prominent, which makes it very easy to locate the tooth as belonging upon either the right or left side of the mouth. Frequently the roots of the third 24 IRREGULARITIES OF THE TEETH. molar unito, forming a single root, slightly curved to \vanl tlir hueeal Mirfaer of tin- jaw. The l..\ver hi.-isnrsiKig. -:i. tfos. i and 2) are not so large as the superior incisors. The lahial and lingual surfaces are straightcr than tin- eonvsj>oiiding surfaces of the supe- rior incisors, while 'the mesial and distal angles are 1-oth right angles. The laterals are broader than the centrals, whieli is just the reverse of the superior incisors, and tin- roots are single, conical, flattened upon their mesial and distal surfaces, and grooved longitudinally. The ( 'usj.ids (No. 3) are slightly convex upon their labial surfaces and somewhat concave upon the lingual .-urfaees. their crowns terminating in a point. Each of them has a Fir,. 9. single root, which is longer than any of the roots of the inferior teeth, conical in shape, but slightly flattened upon the mesial and distal sides, and inclined toward the first bicuspid. The Bicuspids (Xos. 4 and 5), two in number a first and .-eeond are situated posterior to the cuspids; they have round crowns, which are rather concave upon their grinding surfaces, and a groove running through the centre divides the crown into two parts, a buccal and a lingual cu-p. Unlike the superior bicuspids, the outer cusp is the larger and re-en ihles the cuspid tooth, while the lingual cu-j> is small, being sometimes scarcely developed. The second bicuspid is larger than the first and more PART I ANATOMY. 25 spherical in shape. The roots are single and more or less flattened on their mesial and distal surfaces, and smooth, with a deep groove running through their entire length. The Molars (Nos. 6, 7 and 8) have large crowns, with two roots and five cusps, three buccal and two lingual, the ante- rior cusps being the larger. The second molar has four cusps, w r hich are divided by a crucial depression. The third molar has also four cusps, but they are less distinct than those of the second molar. The anterior root of these teeth is broad and flattened FIG. 10. upon its mesial and distal surfaces, while the posterior root is rather oval. The roots of the third molar are never uni- form, being sometimes short, sometimes long, separate or fused together, straight or curved tow r ard the angle of the jaw. TEMPORARY TEETH. Iii general .outline, these teeth resemble the permanent teeth. The crowns are much smaller than their namesakes in the permanent set, and the roots are larger in proportion than those of the permanent set. The pulp chambers in the 26 IRREGULARITIES OF THE TEETH. temporary teeth an- aU> larger in proportion to the size <>f tin- tooth. In other n-pecN the crowns of the incisors ami cu>pids resemble those of tin- permanent set so closely that further description is unnecessary. Tin- molars resemble tin- permanent molars as regards their grinding surfaces ami general outline, but are mneh smaller, being from one-half to two-thirds the size of tin- permanent molars. Occasionally, it is difficult to distinguish them: but when other resources tail, an unfailing way of determining to which set the tooth belong- i- to carry tin- point of an excavator down along the buccal surfa.-. until it reaches the gum. If it be a temporary molar, tin- instrument will suddenly fall into the neck of the tooth, win-re the enamel stops abruptly; while, if it be a perma- nent tooth, the instrument will gradually glide down tin- enamel until the neck is reached, the enamel of tin- perma- nent tooth gradually tapering to a thin edge. The roots of the temporary molars resemble those of tin- permanent in form, but diverge considerably to admit the crown- of the permanent teeth between them. CHAPTER II. THE OCCLUSION OF THE TEETH. The teeth of man have a fixed normal relation to one another, and a position in the jaw which best adapts them for the purpose intended, i. e., that of cutting, triturating and grinding food. It is easy to determine to what class an animal belongs by examining the shape of the teeth and the articulation. When in normal position the teeth are in close contact, and FIG. 11. serve as a support to each other, like the stones in an arch. The arch of the teeth varies as much in nations and indi- viduals as do other racial characteristics. The size and shape of the arch affect the appearance as much as, or more, than any of the features. For instance : a small face with a wide-spreading arch would be a great detriment to beauty, or the association of a large face with a narrow arch would result in a face entirely devoid of beauty so far as features are concerned. 27 28 IRREGULARITIES OF THE TEETH. The outline of .tlu- juvh naturally depends upon predomi- nating characteristic^ ; the Englishman, for example, with tin- round, large head, having a correspondingly large arch (Kg. Hi. Figure 12 illustrates the typical arch ot the American woman, narrow aiil small. 1 Jet \\ven these typical examples !' the two extremes range all of the intermediate grade> of characteristic arches. These arches are perfect in contour, ami vet neither can he taken as a standard hy which to regulate all teeth. Judgment must be used in deciding these points before beginning an effort to change the shape i. 12. of the arch or the position of the teeth. The teeth are arranged in the alveolar process along the border of the superior and inferior maxilla- in such relation to each other as to form an arched contour. When the jaws come together, the superior set occlude outside of the inferior teeth, demon- strating the fact that the superior arch describes the segment of a larger circle than the inferior. The superior centrals are wider than the inferior centrals, so that they extend over a part of the inferior laterals. The upper laterals cover the remainder of the lower laterals and a part of the lower cuspid. The superior cuspid covers the posterior half of the PAET I ANATOMY. 29 inferior cuspid, and the anterior half of the first lower bicuspid, and the relation of the two sets continues in the same proportion to the end of the arch. By this arrangement of " breaking joints," each tooth is antagonized by two in the opposite jaw. This is an import- ant fact when a tooth is lost, as those remaining are held in position by the occlusion of the teeth opposite, and so retain their usefulness. THE CROWNS AND ROOTS. Ill studying the teeth, it will be observed that the charac- teristic teeth of the stout, thick-set man are those with crowns broad and short, and roots long and firmly set in the jaw ; while the teeth of the tall, slender person are characterized by narrow, long crowns and very short roots. Teeth with long roots and short crowns require more force in regulating, and less progress is made than with teeth hav- ing long crowns and short roots. Care must be exercised in distributing the force with teeth having short roots, to pre- vent their being pushed out of their sockets. The roots are more liable to be deformed than the crowns ; they may be bent or twisted, enlarged at the apex, divergent or adherent, or the root or roots may be in contact with roots 'of other teeth, and sometimes extra roots are attached. All these abnormal conditions tend to complicate operations. THE TEETH IN POSITION IN THE MAXILLAE. The teeth are held firm in their alveolar sockets by a union called gomphosis, which resembles the attachment of a nail in a board. Teeth with one conical root, and those with two or more perpendicular roots, are retained in position by an exact adaptation of the tissues. Teeth having more than one root, and those bent or irregular, receive support from all sides by reason of their irregularity. The teeth are also held in position by the peridental membrane (situated between the alveolar process and the root), by the blood ves- sels at the apices of the roots, and by the gum, the tissues of 30 IRREGULARITIES OF THE TEETH. which an- continuous with those of the mucous and peri- dcntal iiieinKranes. Fig. 13 illustrates the position of the teeth in the jaws. The peridental membrane lines the alve- olus and covers the roots of the teeth. It is a fibrous tissue. which admits of a slight motion to the teeth, an- 1 art- MS a cushion to protect the jaws from severe blows ami coneus- while in the act of tearing and grinding food. teeth are in such close proximity that a rul ^ er < la n i or floss silk cannot he inserted hetween them without con- Flii. 13. sidera hie pressure. This tissue is so elastic that teeth that have Keen forced slightly apart will return to their normal portion when they have Keen relieved from pivs.-ure. This membrane is nourished both by a branch of the artery which passes through an opening in the jaw and the apex of the root and by arteries passing through the alveolar process and mucous membrane at the neck of the tooth. The nerve supply is derived in a similar manner. CHAPTER III. ETIOLOGY OF IRREGULARITIES. IRREGULARITIES OF THE TEMPORARY TEETH. Irregularities of the temporary teeth rarely occur, because of the fact that in. their development they meet no obstruc- tions in the jaws. They are so small, and the growth of the jaw is so rapid, that the teeth have abundance of room. Absorption and reproduction of bone go on rapidly at this period, and the crypts containing the teeth being located near the surface of the bone, the teeth pass through without difficulty. The alveolar process is regularly formed, excepting an occasional irregularity from some freak of nature. When irregularities do occur, they are frequently the result of thumb-sucking or some similar cause, or of the inharmo- nious development of the jaws. The habit of thumb-sucking must manifest itself during the retention of the first set of teeth, as it is acquired from the fifth to the eighteenth month, and the temporary teeth erupt about this time. Irregulari- ties from thumb-sucking are never uniform. They may be located in the centre of the jaw or upon either side, depend- ing upon the hand used, and the thumb or finger inserted. The teeth of either jaw may be prevented from erupting, or the process from developing, by the pressure of the thumb. Fig. 14 will illustrate the case of a child six years old, who contracted the habit at about the tenth month. It will be observed that the teeth of both jaws have erupted to nearly or quite their normal length, notwith- 31 Fi 32 IRREGULARITIES OF THE TEETH. standing tin- piv--mv produced by closing the jaws upon the thumb. The maxillary bones, however, have been retarded in growth. The teeth of tin- inferior maxilla do not articu- late properly with those of the superior maxilla, which is caused by the thumb rotating after the jaws are closed, thus throwing the lower jaw to the left. The hard palate was flat and normal, showing that the pn-.inv was direct upon the teeth, and that the thumb did not come in contact with the tiues of the mouth. The superior jaw and teeth may be brought forward by absorption and deposition of bone, and the lower teeth and jaw carried backward in the same manner by pressure of the thumb (Fig. 1 "). The inferior maxilla may, by this cause, be car- Fio. 15. 1 i... 16. ried backward and the angle be a right angle instead of an obtuse one. In thumb-sucking the arch takes the oval shape ratlin- than the sharp angle called the V-shaped arch, unle the teeth project, in which case they have the fan-shaped appearance. In the irregularity known as the prognathous or under-hung jaw, shown in Fig. 16, the anterior teeth of the lower jaw project beyond those of the upper. This is sup- posed to be an inherited deformity. It seems, rather, to be the result of inharmonious development of the superior and inferior maxillary bones; the rami of the jaw do not as-ume the proper angle with the bo.lv at a proper time in life, or the rami are longer in proportion to the body or to the superior maxilla. PART I ANATOMY. 33 It is not advisable to correct irregularities of the temporary teeth, as the jaws are expanding rapidly and the teeth remain but a few years. The appearance of the first teeth has no effect upon the permanent teeth, and is no indication of the shape or position of the second set. This fact, if impressed upon the minds of parents, would relieve the minds of many. IRREGULARITIES IN THE SIZE OF THE PERMANENT TEETH. By comparing the teeth of the present generation with those found in skulls from one to three thousand years old, it will be observed that the size of teeth have altered very slightly. Teeth are generally regular in size ; occasionally, however, may be seen excessively large crowns in the central incisors of the upper jaw, and in rare cases we find one incisor larger than the other. Such deformities are neces- sarily conspicuous. When the crowns are unnaturally large the roots are usually short and stunted, and cen- trals with large crowns are usually associated with small laterals. The laterals, however, are seldom larger than normal. When the cuspids exceed the normal size they affect the expression of the face more than any of the other teeth, giving great prominence to the features and a resemblance to the carnivora. The bicuspids and molars are usually normal as to size. The teeth more commonly fall below the average size than exceed it, which fact is particularly appli- cable to the lateral incisors and wisdom teeth. When the laterals are abnormally small, they assume a conical shape, the extremely small ones resembling the teeth of the cat. When, as is sometimes seen, the follicles of two teeth unite, the result presents the appearance of a single tooth, the roots of which are divided, and this is the only means of showing the preexistence of two separate teeth. 34 Ii:i;i.(.I I.UMTIES OP THE TEETH. iKm:. ri. \UITIKS IN THI: NTMMKR OF THE FKI;M ANTAT TEETH. Tho normal number of permanent teeth is thirty-two, hut from various causes tin- full complement is not nlway- reached, and. on the uth.T haiid.it is sometimes exceeded. We cannot amve with Tomes and Salter, who claim that when an irregularity in nuiiilHT exists it is more likely to .-1 than fall below this number. When there are more than the normal number, the super- fluous teeth are calle 1 supernumerary teeth. They may iv-emMe the natural teeth, or may take a form perfectly rou ml ami conical, with short root, or the crown is flattened and the catting edge serrated. Supernumerary teeth which arc similar to any of the natural teeth generally roemble the incisors or molars. We have never seen a second canine or a third bicuspid upon only one side of the jaw. Mr. Salter has observed two canines in one individual, and one example of a supernumerary bicuspid tooth. When the central or lateral has a supernumerary of a .-imilar form by its side, it is usually difficult to distinguish the normal from the supernumerary, the latter bein^ nearly perfect in form. The lateral incisor is more commonly duplicated than the central. Wisdom teeth are sometime- accompanied by a supernumerary, in which case there will be four molars upon one side. When the temporary teeth remain in connection with the permanent ones, they arc not clashed as supernumerary teeth. The conical and serrated supernumerary teeth are usually found as-ociated with the incisors or wisdom teeth. When found in connection with the incisors, they are cither situated between the central incisors or in the palatine surface pn terior to the incisors. When joined with the \vihow strong evidence that the wisdom teeth are more perfect and common in existing than in early ra<-. I>r. .1. K. Van Marter, in his study of prehistoric d. ntiean races which existed 500 B. c., says:* "In the photo marked N... 1. the teeth were exceedingly fine in form and preservation. In No. '2, the teeth were equally line, hut only twenty-eight in mini her, with no trace or sign of there ever having he. n thirty-two. In the other skulls I noted the same want of the third molars. Evidently, they were never developed. It is worthy of note that in the comparatively few remain- of prehistoric skulls in the above collection, there should he >uch a proportion of those in which the third molar does not appear. About one-fourth of the third molars were wanting. What, then, becomes of the theory that the wisdom teeth aiv becoming rudimentary and disappearing? iVrhap- they di-appeared once before, and reappeared again in an age ..f wisdom, but are now fading away, marking a decadence in that dental evidence of sage understanding." iRRE(;uL\KTrn:s i\ THE ARRANGEMENT OF THE PERMA- NENT TEETH. At the age of six years, the temporary teeth and the tir-t permanent molars are in their places in the jaw. I5y remov- ing the outer plate of bone in the jaw. it will be seen that the germs of the permanent teeth are in their crypt-, a- is shown in Fig. 18. While the teeth grow independ- ently of the alveolar processes, the processes depend to a great degree upon the teeth for development. \Vith t! various conditions existing at the same time, it i< not sur- prising that the teeth are erupted out of a normal position. The alveolar processes are, to a certain extent, independ- ent of the jaws. The parts below the mental foramen on * Iml< i ml, nl PART I ANATOMY. 37 the lower jaw, and above the palate on the upper jaw, are hard and dense, and are for the attachment of muscles. The alveolar processes, composed of soft and yielding tissue, are expressly for the purpose of the formation of the teeth while in the crypts, and for their retention after they have erupted. When the teeth are removed, the processes are absorbed, and nothing remains in old age but the dense bone. In intra-uterine life, while the teeth are forming, the alveolar processes cover and protect the crypts in which the germs are located, and as they grow and force their way FIG. 18. through the processes, absorption takes place and most of the bone vanishes. After they have passed through, depo- sition of bone again takes place for the purpose of holding them firmly in place. Again, these teeth are shed and bone is absorbed to admit the second set of teeth, after which new material is deposited for their retention. This is the case under all conditions of their eruption, whether regular or irregular. From the time the first teeth appear until the second set are firmly fixed in position, the alveolar process 38 IRREGULARITIES OF THE TEETH. has changed throe times; consequently, while the teeth grow and develop independently of the alveolar process, the pro- cesses are, to a certain extent, dependent upon the teeth for their development, po-ition and shape. Tin- permanent teeth, taking the place of the temporary teeth, and likely to be dellected in any direction hy the slightest obstruction or want of space, are, indeed, " creatures of circumstances." Mr. Tomes says: "The point upon which it is impossible to insist too strongly is this, that the teeth, when they are erupted, do not come down and take their places in a bone already prepared for them; on the contrary, that which is there to start with is absorbed, and the bone in which they are ultimately implanted is built up around them, no matter what position they assume subsequent to their eruption." The size of the jaw does not indicate the size of the alveolar process. The teeth may erupt toward the inner border of the jaw, when the process will naturally build up about them, and will be smaller than the jaw; w r hile, on the other hand, the teeth may be directed outward, and, as a result. the process will be larger than the jaw. In whatever position the teeth make their appearance in the jaw, the cheeks and lips add materially in directing their position externally, and the tongue internally. The order in which they are erupted may have as much to d< with the causation of irregularities as any one thing. This is particularly noticeable when the bicuspids and lateral incisors come down in close proximity, and the cuspids are left outside the arch, or when the centrals, the laterals and cuspids are in place, and some of the bicuspids, which have been retarded in their eruption, are forced abnormally inward. Lateral incisors and wisdom teeth are rather frequently out of position, since their tardy development allows the other teeth t -cupy the space. It will be observed that the crowns of the permanent centrals, on the lower jaw, are situated below and posterior to the roots of the temporary teeth. The permanent crowns. PAET I ANATOMY. 39 being larger and requiring more space, naturally crowd out- ward and conflict with the roots of the temporary teeth, thus producing absorption of the entire root. The roots of the temporary teeth may be all removed by nature in this same way. If the crow r ns of the permanent teeth do not come in contact with the roots of the temporary teeth, or if from any cause the pulps of the deciduous teeth are destroyed, absorption does not occur to any extent, and the roots are not removed. The permanent teeth are then FIG. 19. deflected either into the mouth or out toward the labial or buccal surfaces, or they remain imbedded in the jaws. AVhen temporary teeth are extracted on account of decay, or to make room for the permanent teeth, the cavity occa- sioned by such extraction fills up with osseous matter, which deflects the permanent teeth outward or inward, since the tooth cannot penetrate it. Fig. 19 illustrates a case of this kind ; a represents the site of the extracted deciduous tooth filled with cicatricial tissue ; b, the permanent canine, which has been deflected outward. IIAPTER IV. At QUIRED IKKi:.l I.AKITIKS. I'M ler tin- general head of etiology of acquired irregular- ities may In- mentioned tliuml), lip, ringer and longm- sucking, and long-continued nipple and sugar-teat sucking. Sonic common forms of irregularities are a-crihed by dill'er- cnt writers tn thumb-sucking, which, in the author's opinion. cannot be classed under that head of causes. Ind.-.-d. \\. think that irregularities in the permanent teeth arc very rarely the result of thumb-sucking. It is a habit acquired in infancy and continued while the first teeth are in the jaw. when the roots are small and short and very impressible. The upper teeth are easily pushed out and the lower pre<-ed in bv anv constant force. Thumb-sucking tends to enlarge the arch, and, by throwing out the surfaces of the upper teeth . will make spaces between them, at the same time making proper occlusion of the teeth an impossibility. Fig. 20 i- taken from the collection of Dr. E. D. Swain, of Chicago. If the habit be not overcome when the second -et appear-, the superior incisors will be pushed out, making a tan- shaped arch, and the pressure of the object will produce absorption of the processes, or the alveolar process will assume the shape of the object sucked. In the lower jaw the irregularities are reversed: while t In- upper teeth are thrown out, elongated and spread apart, the lower incisors are forced inward, shortened and crowded together. Pressure upon the lower jaw in thumb-sucking has a tendency to shorten the angle of the jaw: absorption and deposition of the bone take place, so that the lower teeth articulate one tooth back of the normal position. Dr. Ballard, of London, observed that the prominence of the central incisors and the vaulted arch was common with idiots, and concluded that thumb-sucking was the cause of this prominence, and, consequently, of the idiocy. While it 40 PART I ANATOMY. 41 is a fact that this peculiar deformit}' is more frequently found among a given number of idiots than in the same number of healthy persons, it cannot be a result of thumb- sucking, for the following reasons : First, if the irregularity were produced by thumb-sucking, the deformity would exist on one side of the median line, according to the hand which was used, rather than at the median line, where most of these irregularities are located ; secondly, the vaulted arch could not be produced by thumb-sucking, as the thumb could not reach the roof of the mouth to produce sufficient pressure to affect the arch. The vaulted arch and the V-shaped FIG. 20. jaw are not always associated, the V-shaped jaw being as frequently unaccompanied by the vaulted arch as it is found with it. It is agreed that the thumb-sucking during first dentition changes permanently the shape of the jaws ; but before the maxillary bones could be affected the teeth would be thrown out of position, and, as has been remarked before, irregular- ities of the first set of teeth are seldom seen. Sucking of the tongue and sugar-teats is more likely to produce deformities of the bicuspids, molars and hard palate than of the anterior 4 42 IRREGULARITIES OF THE TEETH. teeth, mving t> the position of the tongue. Deformities occur at tlir point where the pressure is the greatest. THE CENTRAL INCISORS. The central incisors are usually regular in their position, owing to the manner in which they are erupted. They seldom meet with resistance in their transit. a> they come . Shepard, of Boston. The right cuspid appears through the gum l.e- tween the central and lateral incisors, while upon the left side a su- pernumerary tooth stands between the cen- tral and laternl. and the left cuspid is erupting between the lel't central and the supernumerary tooth. The pro- lire of the cuspids i- -o M-]v;it in the jaws as to demoral- ize all theanterior teeth. Fig. 23 illustrates tin- model, pre-elited to Hie by Dr. John S.Marshall. of Chicago, of the lower jaw of a woman thirty-seven years of age. It shows the right permanent cuspid situated between the central incisors. This tooth made its appearance when the patient was thirty- two years of age. The right temporary cuspid is still in place. \\ hen th<- crown of the cuspid is on the palatine surface PART I ANATOMY. 45 FIG. 21. of the roots of the laterals and bicuspids (especially if the temporary canine remain in the jaw), it will deflect into the roof of the mouth. Fig. 24 illustrates such a case. When the cuspids begin to erupt they sometimes strike the roots of the lateral incisors, or the first bicuspids, or both, and are rotated in their sockets on the principle of the inclined plane. The molars and bicus- pids may work forward and fill all the space, either because the tem- porary cuspids have' been extracted too early or retained too long, and the permanent cuspids remain imbedded in the jaw. Irregularities in the arrangement of the bicuspids and molars are treated under the heads of irregularities caused by protracted retention and too early extraction of the tem- porary teeth. The causes already enumerated which pro- duce irregularities of the teeth of the upper jaw are also responsible for the irregularities of the teeth of the lower jaw. Added to these causes is the contact of the inferior with the superior teeth. Frequently the cutting edges of the lower teeth, in their development, come in contact with the contracted arch of the upper jaw, and are turned from their regular course. These irregularities are difficult to correct. HEREDITY IN ITS RELATIONS TO IRREGULARITIES. It is a fact universally recognized that various morbid conditions and peculiarities of structure are often transmitted from parent to child, through many generations. This law of heredity is almost universal in its application, and its 46 IRREGULARITIES OF THE TEETH. influencr 1'iay be either enhanced or depreciated through Micces-ive or alternate generations, until we have, upon the our han.l, a total disappearance of the hereditary impression, or, upon the other, an increase so great that the condition become incompatible with the life of the individual. This variation i.< a fortunate circumstance, as by it the human raer i- protected from certain destruction. This plan of variation is powerful for good or evil, accord- ing to the environment of the individual, or of the family to which lit- belongs. This fundamental evolutionary law of heredity is nowhere more manifest than in the case of per- versions of development of both internal and external organs, cither embryonal or post-natal, and it is a mdst powerful factor in the production of deformities of the jaw and irregu- larities of the teeth. Not only does this hold true in the e of general irregularities due to maxillary deformities, but it also applies to malformations of individual teeth. Thus, the author has observed in a family consisting of mother, daugh- ter and granddaughter, a peculiar fissured condition of the enamel upon the labial surface of a left superior lateral incisor. It is not uncommon for a child to possess peculiarities of the teeth of one jaw resembling those present in the father, while the other presents irregularities of development pre- cisely identical with those present in the mother : a gain, one parent may transmit peculiarities of maxillary development while tin- other transmits certain characteristic appeara: of the teeth. Much has been said of late regarding the influ- ence of ante-natal impressions upon the development of deformities, and if the claims advanced be but half true, it is probable that the teeth and jaws may occasionally sutler their share of the resulting detriment. Evidence of dental deformities from this cause is, of necessity, difficult to obtain. A case is recalled, however, in which a peculiar condition of irregularity of the teeth was attributed by the mother to h'-r constant worry, during gestation, lest the coming child should have teeth as irregular as her own. When dentition was PART I ANATOMY. 47 finally completed in the child, the arrangement of the teeth was identical with those of the mother. This case is not by any means advanced as a positive evidence of ante-natal impressions, but b3cause of its suggestiveness. Notwithstanding what has been said regarding the influ- ence of heredity, it must be confessed that we are often abso- lutely unable to determine the precise degree of influence exerted by it, even when we are convinced that it is a pow- erful factor. It is evident to any one, upon reflection, that the causes which will produce deformities independent of hereditary influences will also prevent the latter from acting as they otherwise would. As has been remarked elsewhere, the teeth are creatures of circumstances, i. e., they are developed independently of the alveolar process, hence their order of development and the resistance imparted by other teeth and roots all combine to pro- duce irregularities ; in short, local causes produce a majority of irregularities, and modify formations which might other- wise be the exact counterpart of those presented by the teeth of the parent. The following cases in practice illustrate this theory. In one family under my observation the father's jaws are well developed, and con- tain large, strong teeth. The mother's jaws are small, the teeth being regular in the lower max- illa. In the upper maxilla the central incisors are regular and in normal posi- tion, but the cuspids, bicuspids and mo- lars have come for- ward and filled the spaces occupied by the laterals, which were extracted at the FIG. 2o. FKI. 2fl. 4g IRREGULARITIES OF THE TEETH. aee of thirteen. Two sons (their only children) have lower jaws and teeth closely resembling the mother's. The upper jaws and teeth of both resemble the father's in size and Strength, but, unlike the father's, they are very irregular in position These irregularities are not due to roaoe in the jaws, which are sufficiently large to admit teeth with regularity. This tendency to irregularity of posi- tion i< apparently a marked inheritance from the mother. Fig 25 is tin- model of the jaws of the elder son, who is four- teen years of age; as may be observed, the central incisors .,t the upper jaws are regular, the laterals are forced l.y the cus- pids some distance inside the natural line; the cuspids, bicui- pids and molars are anterior to their nor- mal position. Fii:. 26 illustrates the jaws of the younger son, aged eleven. Tin- centrals and laterals erupted at the pn.per time. The cuspids are encroaching upon them to such an ex- tent as will eventu- ally form a Y-shaped arch. Both boys have been under my care from the begin- ning, the temporary teeth being removed at the proper time. It will be observed that the tendency toward irregularity in arrangement is decidedly inherited from the mother. The renditions are so modified by local influences that although the hereditarily irregular arrangement comes in mi the mother, the teeth are not exact counterparts of the mother's irregularity, nor are they alike. It is questionable whether exact counterparts of irregularities are ever inher- ited from parents. Various local interferences and condi- tions will, as we have seen, influence this one way or the PART I ANATOMY. 49 other. Transmissions of small jaws and of peculiarities of individual teeth are, however, common. In 1864, Messrs. Cartwright and Coleman,* of London, examined some 200 skulls in the crypt of Kythe Church, Kent, which had been deposited there for centuries. They found the alveolar processes and teeth perfectly developed and formed. In 1869, Mr. John R. Mummery, of London, read a paper before the Odontological Society of Great Britain, in which he gave a report of his extended researches, including over 3000 skulls of ancient and modern uncivilized races, and concluded that the early and half-savage people were freer from dental irregularities than moderns. Dr. Xichols, of New York, has examined the mouths of thousands of In- dians and Chinese, and says that, with but one exception, he never found an instance of irregularities in either of these races. 1 can confirm the statement of Dr. Nichols as regards the Chinese, having examined the teeth of many of them on the Pacific coast. The above reports, together with the testimony of other investigators, show that ancient uncivil- ized and nomadic barbarians have perfectly-shaped dental arches. The interesting circumstance that irregularities occur more frequently now than formerly, and among people living in new countries, would suggest the idea that irregularities caused by heredity may result from the intermarriage of different nationalities, the offspring of such unions partak- ing irregularly and in different degrees of the racial pecu- liarities of maxillary development of either or both parents, [t is probable that the varying character of the food, and the abuse of the teeth incident to the depraved hygiene of lodern civilization, have much to do with dental malforma- ions. Again, the higher the evolutionary type of indi- viduals, the more imperfect the teeth and jaws become. Kingsley's "Oral Deformities." 50 IRREGULARITIES OF THE TEETH. The nearer the monkey, and the farther removed from refined and civili/ed man, the better the teeth. As the animal becomes less and less dependent upon his jaw- and teeth fnr a livelihood, the less perfect these strut-tun -s become, and after the lapse of many generations marked variations and imperfections of development are logically t> lie expected. Iii conclusion, it may be said that in our studies of dental and maxillary irregularities. \ve must not only take into consideration the transmission of individual peculiarities, hut the all-pervading and general evolutionary law of In rulity. ARRESTED MAXILLARY DEVELOPMENT AS A CAUSE OF IKKKtilLAKITIES. The superior and inferior maxilla3 are developed from separate and distinct ossific centres, those of the inferior U-ing the tirst of the bones of the skeleton to exhibit signs of ossification; not only do the maxilla? develop independ- ently of each other, but each bone is practically developed in two lateral halves, which subsequently unite by fusion. the line of fusion becoming finally more or less obliterated. The teeth, already laid down at birth, develop and grow independently of the maxilla3 and alveolar processes. Under such circumstances of development and growth it is obvious that perfect harmony must exist, else deformity is sure to ensue, e. g., the separate halves of the maxilla- must have a corresponding degree and mode of develop- ment, else irregularity is inevitable. In the same way. a difference in the form of the upper and lower jaws may atlect the regularity of the teeth. A lack of correspondence between alveolus and jaw. or jaw and teeth, is almost certain to cause serious deformity. The greater deformities due to inharmonious development, such as cleft palate, harelip, underhung jaw and protruding upper jaw, are sufficiently familiar, but their relation to irregularities is not generally appreciated. Violate the general PART I ANATOMY. 51 developmental law of harmony, and we may have deformi- ties which, although varying in degree, are precisely iden- tical in kind. When the fact that the foetus is practically developed in two lateral segments is taken into considera- tion, all deformities which exist, or a predisposition to which exists, at birth become easily understood. There is a marked difference between the superior and inferior maxilla in respect to congenital and acquired deformities. The superior maxilla is exposed to pressure and many extraneous influences due to the arrangement of the various bones with wljich it articulates there being eight of these articulations. The lower maxilla is developed free and independent of the other bones of the face, and, as a consequence, is in nowise affected by any lack of harmony which may exist between them. Thus, the fact of the relative infrequency of deformity or imperfect development of the inferior maxilla, as compared with the superior, is readily explained. There is another plausible explanation for this difference : The upper jaw, being fixed, is not actively exercised, and, consequently, has no special stimulus to development ; the lower jaw, on the other hand, is mobile, and acted upon by powerful muscles in such a manner that an active blood supply becomes necessary. With this increased blood supply comes increased growth and nutrition. There is this to be said, however, in relation to this subject, etc., viz. : that the lower jaw is more likely than the upper to present family characteristics of configuration not within the range of actual deformities. From what has been said, it is obvious that the considera- tion of deformities due to arrested development must neces- sarily be limited to the upper jaw. These deformities merit special attention. There are two principal deformities dependent upon mal-development of the superior maxilla, viz.: The Y-shaped arch and the saddle-shaped arch. The most common of the two forms is the V-shaped arch (Fig. 27). The incisors protrude and are rotated in such a manner that their mesial surfaces present anteriorly, forming the point 52 IRREGULARITIES OF THE TEETH. of the V, the bicuspid region is contracted, and the roof of the mouth may or may not be vaulted; the cuspids are sometimes in the line of the other teeth, and sometimes entirely outside the arch ; we occasionally find in these cases tin- lid ration is the fact, that, if due to thumb-sucking, the deformity would \>e most likely to be upon one or tin- other side of the median line, according to the position of the force, instead of at the median line. The spaces \isting between the teeth of the thumb-sucking child are never seen in the V-shaped arch. It is noteworthy, also, that the thumb cannot well be car- ried into the mouth so far as would be necessary to the Fio. formation of the V-shaped arch ; and even were it possible, the resulting deformity would be an arc of a circle rather than an angular V. Fig. 28 shows a perfectly Hat arch, the anterior teeth rounded out, with space between them. This is a marked case of thumb-sucking in a child al><>ut fourteen years of age. Dr. Kingsley is probably correct in so tar as the relation of heredity to the small, undeveloped maxilla is concerned, but that the V-shaped arch is due to heredity per se is questionable. When it does occur, it is by acquire- ment from causes acting locally upon an hereditarily small maxilla. At the beginning of the V-shaped arch we find PART I ANATOMY. 55 the following conditions : The first permanent molars are firmly fixed in the jaw, owing to their size and long roots, the centrals and laterals have erupted, both bicuspids are descending into place against the firm first molars. Owing to the lack of space which obviously exists in the imper- fectly-developed maxilla, with which the V-shaped arch is always associated, these teeth cause the alveolar process to be carried forward by absorption and deposition of bone. This forward movement takes place at the point of union of the inter-maxillary and superior maxillary bones. The roots of the six anterior teeth, being conical in shape, FIG. 29. press forward and inward in a rotary manner, the cuspids against the laterals, the laterals against the centrals, and, assisted by the pressure from the muscles of the cheeks and lips, produce an arch, which takes the V shape. Fig. 29 shows the model of the jaw of a boy fourteen years old, demon- strating the cause of the V-shaped arch. The right side is normal, excepting the lateral incisor, which is slightly rotated in its socket. The left side forms half of a perfect V-shaped arch. The abnormal position is owing to the too early extraction of the temporary cuspids, thus giving space IRRFXJULARITIFJS OF THE TEETH. for the fir>t permanent molars and bicuspids to work for- ward. They iilled one-fourth of an inch of the spare made vacant by the loss of the temporary cuspids, and forced the permanent cuspid, when erupted, forward. The pressure of the cuspid root, ami of the lip and cheek, have carried the lateral inci-or into the palate and rotated the centrals around. Had the sain conditions existed on the right side, the V-shaped arch would have been complete. The cuspids may le located in a direct line with the other teeth, or. from want of room, may be situated entirely outside the arch. The died of pressure of the cuspids npi.n the alveolar process in cither case is precisely the same. THE SADDLE-vSHAPED JAW. Another deformity of the jaw and teeth which is also attributed to thumb-sucking is illustrated in Fig. :!<). and is called the ".-addle- shaped jaw." The ante- rior teeth an- usually in a normal position. They either stand straight from the alveolar pro- ' ss or the cutting ed project slightly. They are seldom irregular in position, l.eing protected from the anterior j ress- ure of the posterior teeth by the cuspid teeth. When, as is occasionally the case, the deformity exiflta on the lower jaw, we find the incisors and cuspids in a straight line. This straight appearance of the anterior teeth is produced by the anterior pressure of the hidi>pids and molars against the cuspids, which are carried forward on a line with the incisors. The bicuspids and lirst molar- are situated considerably inside of the arch the second PART I ANATOMY. 57 and third molars taking an oblique direction laterally, with the roof of the mouth vaulted. Like the teeth of the V- shaped arch, the first molars, bicuspids, cuspids, and some- times the incisors, are wedged close together. This fact would naturally suggest as a cause the want of develop- ment of the jaw. A gentleman under my care is possessed of fine physique and well-developed frame, but has peculiarly small jaws and processes compared with the other bones of the body. The teeth of the upper jaw form almost a V-shaped arch, those of the lower jaw the saddle-shaped arch. Like the V-shaped arch, the saddle-shaped arch does not begin to form until after the eruption of the first permanent molars. This deformity has its primary cause in the location of the crowns of the permanent teeth in a dwarfed alveolar process. Instead of the bicuspids and molars being located in the jaws in their normal positions illustrated in Fig. 31 by A-B they stand on a line rep- resented by C-D. This abnor- mal condition in the jaw may be a natural position of the follicles, or the bicuspids may be influenced by the roots of the temporary teeth and the crowns directed toward the roof of the mouth. On the eruption of the per- manent teeth, the order is X C changed considerably : the centrals and laterals come into position in their natural order, but instead of the bicuspids making their appearance next, the cuspids take their positions. These teeth make a fixed point of resistance in the anterior part of the mouth. The first permanent molar, which is already in position with its long and large roots, is working forward, and has also become a fixed point in the posterior part of the mouth. The space between the first molar and the cuspid is smaller 5 -,s IRREGULARITIES OF THE TEETH. than the long diameter of the crowns of the bicuspids, and both an- crowded in toward the roof of the mouth. It sometime-, happens that the first bicuspid erupts and sect] it> position 1 w fore tlie second bicuspid makes its appearance. In this case the crown of the first permanent molar, in work- ing forward, comes in contact with the crown of the sm.nd bicuspid in siu-h a manner as to form an inclined plane, and in this way the second bicuspid is carried inside the arch and is often turned in its socket, the cusps facing the ante- rior and posterior parts of the mouth. Nature provides sup- port lor the teeth in whatever position they may a nine; the alveolar process is built up about them, giving them strength and firmness. The extreme lateral position and undeveloped condition of the second and third molars and the alveolar proce> caused by the pressure of the tongue. The arch. lein^- con- tracted to such an extent that the tongue, in the act of >\\ allowing, is forced backward, consequently thickens and spread- out and produces pressure upon the posterior part of the upper and lower jaw. The same condition of the teeth i> also noticeable in the jaws when the arch is very shallow, and is also the result of a want of room. It is a mistaken idea that the high arch is always associated with the V- shaped. the saddle-shaped arch, or the arch of the tlr'inb- sucker. The author has observed many such cases, and has noticed quite as many with shallow as with high arches. 1 1. 'REGULARITIES CAUSED BY THE PROLONGED RETKMIoN* OF THE TEMPORARY TEETH. The period of life during which the shedding of the decid- uous teeth and the eruption of the permanent set occurs iiio-i critical one in the formation and arrangement of the permanent teeth. The first small teeth are being supplanted by large ones, and at the same time the jaw is changing. The child should at this time be under the care of a dentist who has the ability to assist nature in perfecting the change. If the process be left entirely to nature, complicated deformities PART I ANATOMY. 59 may arise, which, with judicious treatment, might have been prevented. As the permanent tooth shows signs of advancing, the tem- porary tooth upon which it impinges should be examined, and removed if loose or if its room be needed. By attention to this particular, and to the articulation as the teeth take their places, further trouble will often be avoided. Much depends upon the location of the follicle of the per- manent tooth in the alveolar process in its relation to the root of the temporary tooth. These follicles are not always located directly at the apices of single roots or between the roots of the molars, it being common to find them some dis- tance from these points. When this is the case, the vascular papilla (which is situated directly upon the crown of the advancing permanent tooth, and is the organ which nature provides for removing the roots of the temporary teeth) does not perform its function. The permanent tooth will remain imbedded in the jaw, or will deflect to one side, and appear either outside or inside of the arch. We sometimes find the permanent tooth forced against a single root or between the roots of a molar and the surrounding healthy tissue. Again, it is more common than otherwise to find the molars decayed and pulps exposed or dead ; in such cases the roots of the temporary teeth are never absorbed, and the permanent teeth are either retained until these teeth are removed or are erupted in an abnormal manner. Et is a common occurrence to find the crowns of the permanent teeth deflected and making their appearance inside or outside the arch, owing to the long slender conical roots of the temporary incisors and the position of the dental follicle of the permanent incisors. In either case the corre- sponding tooth of the temporary set should be removed and the permanent tooth pressed into place with the fingers. This same condition of the incisors is liable to occur in the upper jaw, but they are less apt to appear inside of the arch than in the lower jaw. AVheii this occurs, the temporary teeth must be removed and the permanent centrals be pushed 60 IRREGULARITIES OF THE TEETH. out with the finger until they occlude outside of the inferior incisors. When they appear outside of the arch, and the temporary incisors an- -xtruc -t-d. the pressure of the lips will usually bring them into line. The same conditions occur in regard to the lateral incisors, and the same treatment should be dopted. It is very important to retain the temporary cuspid until the eruption of the permanent tooth. When this time lias arrived, the temporary tooth should be removed to allow the advancing tooth to go into place. Should the temporary tooth remain too long, the permanent cuspid will work its Fir.. 32. way either inside or outside the arch, as illustrated in . 32. This represents the lower jaw of a man twenty-two years of age. The left temporary cuspid is in position and the permanent cuspid has erupted inside the areh. The retention of the temporary molars is a fruitful cause of irregularities. Fig. 32 also illustrates the removal of the first temporary molar and its place filled with the first hicus- pid; but the second temporary molars are in place, and, as a result, the second bicuspid upon the left side is still in the jaw, while the second bicuspid upon the right side has erupted inside of the arch and below the crown of the u-m- PART I ANATOMY. 61 porary molar. Fig. 33 illustrates a case in practice which is one of the most difficult to correct. It is the upper and lower jaw of a girl ten years old. The temporary teeth are all shed from the lower jaw, and the first permanent molars have come forward in such a manner that they prevent the bicuspids and cuspids erupting. The incisors impinge upon the mucous membrane in the roof of the mouth. The tem- FIG. 33. porary cuspids and molars are still in position upon the right side of the upper jaw, and the second molar upon the left side. The first bicuspid is just making its appearance through the gum. Had the temporary teeth been extracted at the proper time, a part of this deformity would have been prevented. CHAPTER V. I K REGULARITIES CAUSED BY TOO EARLY EXTRACTION OF THE TEETH. No one cause which can be controlled by tin- dentist is nsible for so much irregularity of permanent teeth as the premature extraction of temporary teeth. It is an acknowledged fact that temporary teeth require great care in the way of cleansing and filling. In childhood, the size of the jaw anterior to the first perma- n '-nt molar is nearly equal to that of the adult; the growth continues posterior to the molars. The ten temporary teeth are supplemented by the same number of permanent teeth. Physiology tells us that the members of the body must he properly exercised to become strong and fully developed. The teeth are no exception to this rule. Decay of lc -eiduous teeth, exposure and death of their pulps, and. tinally. extract- ing, render the act of mastication difficult, resulting in inaction of the jaws and arrested development. If the deciduous teeth had been properly cared for and retained in the jaw, they would have acted as wedges and ai>ted nature in enlarging the alveolar process. It is claimed that the jaws are not retarded in their growth by the extraction of the temporary teeth. It i- a tact that can be easily, demonstrated, that pressure of an- tagonizing teeth assists in the growth of the jaw. If a thread be drawn between the deciduous teeth regularly each day, and increased gradually in size, it will be observed that tin- spaces between the teeth will increase, showing that the p iv-sure has expanded the jaw. When a temporary tooth i extracted, the alveolar process which formerly surrounded it has no further function and is absorbed. The jaw 1< a certain amount of tissue, which is necessary for the proper support of the permanent tooth, and the diameter of the jaw 62 PAET I ANATOMY. 63 is reduced, producing a crowded position of the permanent teeth. The temporary teeth, when decayed, should be rilled and their pulps preserved as long as possible. They should never be removed until they can be pushed out with the finger, or until the permanent tooth makes its appearance. The permanent centrals on the lower jaw commonly appear posterior to the temporary centrals. The former teeth are so much the larger that they lap over the edge of the tem- porary laterals. When this condition exists, the temporary centrals, and not the laterals, should be extracted. The pressure of the roots of the centrals against the laterals will expand the jaws. A very serious mistake is the extraction of the temporary cuspids to make room for the lateral iii- cisors. The temporary incisors being much smaller than the permanent, when the first teeth are shed the permanent incisors are not only crowded, but often the lateral incisors are obliged to erupt inside of the arch, and frequently the dentist extracts the cuspids to make room for the laterals to go into place. This certainly is bad practice, because, 1st, the anterior part of the jaw will not be properly expanded, as there would be no antagonism of the teeth to produce pressure ; 2d, the laterals, as a rule, will not come into the arch ; and, 3d, the bicuspids, being the next in order -of erup- tion, make their way forward and take a position next to the laterals, thus preventing the permanent cuspids from coming into place. At the time of the eruption of the lateral incisors, absorp- tion of the roots of the temporary cuspids has not commenced. Should the tooth be removed at this period, the alveolar process contracts at that point, which will reduce the size of the jaw, the permanent cuspids being thereby crowded out. A common cause of irregularities is the too early extrac- tion of the temporary molars. These teeth usually decay early, the pulps become exposed or die, and abscesses result. These conditions produce pain, and the teeth are sacrificed. Then the first permanent molars gradually work forward r, I IRREGULARITIES OF THE TEETH. ami oeenpy (lie space of the second bicuspid tooth, the bicus- pi.ls, bring the next teeth to erupt, work forward, and, when fully erupted, antagonize with the lateral incisors, thus rrowding out the cuspids, which are the last to make their appearance. It M number of casts of the jaws were examined when the temporary molars have leen permanently removed, it would be seen that, in the majority of cases, the first permanent molars have mme forward from one-sixteenth to one-fourth of an inch, and have crowded the permanent teeth anterior to the first permanent molar. Some writers advance the idea that when the first permanent molars in both jaws have Flo. 84. erupted so that they occlude, this will prevent forward progn-ion ; but we think this is not the case. These teeth will push forward until they meet resistance. As before mentioned, the temporary teeth should be retained until they 1 onsen from absorption of the roots, or until the per- inanent teeth appear. Fig. 34 represents the upper jaw of a girl ten years of age. The temporary cuspids and the first and second molars upon the right side are in place, thus holding the first per- manent molars in place, while upon the left side the first and second molars have been removed. The first permanent molar has pushed forward a quarter of an inch, making PART I ANATOMY. 65 it impossible for the bicuspids to come into position. This is usually the case with children whose temporary teeth have been removed. The first permanent molar works its way forward and occupies the space of the second bicuspid, thus crowding the anterior teeth out of place. FAILURE OF ANTERIOR OCCLUSION. Want of occlusion is a deformity which does not present itself until the tenth or eleventh year, and is not of common occurrence. Until this period the teeth articulate naturally. The appearance of the teeth then changes; the anterior teeth do not occlude, and when the jaws are closed quite a space is observed. This irregularity occurs at the time of development of the first or second molars, which erupt at greater length than the anterior teeth. This want of occlu- sion may take place when all of the teeth are in the jaw, or after the first permanent molar has been extracted. If the teeth are all in the jaw, the second molar may pass through the jaw farther than the other teeth, as a result of the patient sleeping with the mouth open, thus removing the pressure from these teeth, or the bicuspids are prevented from erupt- ing their natural length by the impingement of the first permanent molars upon them. Teeth which are tender upon pressure, caused by inflamed gums or death of pulp and peridental inflammation, or when, from decay, pulps are exposed and thus prevent mas- tication on account of pain, do not occlude, and the second molar teeth elongate. When the first permanent molars are extracted, the second molars tip forward and the posterior cusps are brought up, causing them to strike the second molars upon the upper jaw, and thus throw the jaws apart. Such a case is illustrated in Fig. 35 (from Dr. A. E. Matteson's collection, Chicago). PROTRUSION OF THE UPPER JAW. This deformity (Fig. 36) does not manifest itself to any extent until after the eruption of all the anterior permanent gg IRREGULARITIES OF THE TEETH. teeth The question of the teeth having spaces lx-t thnii or being crowded together, will depend upon the cause ,f the deformity. In some cases the teeth project so iar that tin- lips cannot cover them when the mouth is closed. M 1 M -n FIG. 35. the alveolar process is involved, there is a fullness of the upper lip at the angle and septum of the nose. The lower lip passes behind the superior incisors instead of covering I';.. H them. There are many causes for this deformity : heredity, -i\f development of the superior maxillary hone, exce* -i\v <>f strong ami feeble-minded persons the larger percentage ulting ])ain IT. ami tin- mechanical force necessary to produce absorption of the obstnu-tivc portions of tin- alveoli is so great, that the end hardly justifies the means. AVhen regu- lated so late in life, retentive and corrective plate- mu>t l.e worn tor years to hold the teeth in place until ossific matt- rial shall have formed to retain them in their new position. In some cases of late correction, absorption of the alveolar process not being followed by compensatory ossific depo>it. the merhaniral interference produces chronic inflammation of the peridental membrane, i. e., a veritable pyorrhoea ah lari.s. I observed this very condition in the mouth of a lady of thirty-live, in whom an extended and. I may add, ill- advised operation had been performed. If the teeth must be regulated at this period of life, the operation should he conducted with great caution and the patient should he duly impressed with a doubtful prognosis. When the patient insists upon an attempt at regulation, and is willing to assume the responsibility of failure, we are perhaps just i tied in operating in any case of reasonable age. Having considered in detail the proper period for regu- lating, we are confronted with another question of perhap- great importance, viz., the general health and constitutional peculiarities of the patient. Inasmuch as the majority of cases for regulation are youthful, this matter of the general health is no slight consideration. It is an unfortunate fact that the most favorable period for operation is one of t In- most critical in the life of the patient, so far as the general health is concerned. From the age of twelve to sixteen, the rapidly-growing boy or girl is subjected to many physical changes, entailing profound disturbances of the general and trophic nei\ systems. Prolonged and injudicious hours of study, over- : tion. had air, improper or insufficient food, sexual irrita- tion, and many other disturbing elements, are apt to become prominent factors in the daily life of the patient. The matter of sexual disturbance is of especial importance PART II TREATMENT. 75 in females, on account of the new function menstruation which asserts itself at this period. When we superadd to these physiological perturbations and circumstances of envi- ronment, the perversion of nutrition consequent upon con- genital weakness, rachitis, hereditary syphilis or the exanthe- mata, the important bearing of the condition of the general health upon our operative procedures is very manifest. We should defer operating, therefore, on young persons in deli- cate health until such time as they have become improved by proper treatment ; and it behooves us as scientific dentists to know something of these general conditions, so that we may, in all conscientiousness, place them in proper hands for constitutional treatment. It is in just such cases as these described that the cooperation of a skillful physician is indis- pensable. A case was recently noted in this city where, from a prolonged operation in regulating, a delicate, pun} r lady was invalided for two years, solely by the shock produced upon a nervous system primarily unstable. PHYSIOLOGICAL AND PATHOLOGICAL CHANGES. It is apparent, to a close observer, that the teeth are con- stantly changing their positions in the jaw, absorption and deposition of bone going on simultaneously and continu- ously. This is particularly noticeable at the first eruption of the teeth, and again from the twelfth to the sixteenth year. When the first permanent molar has been removed, the second and third gradually press forward and fill the space. It will also be noticed that teeth that are erupted out of their position will, in time, often find their way into their proper places ; also, when the molars and bicuspids are lost late in life, the anterior teeth are forced forward, thus causing the alveolar arches to project. Again, it is found that when the anterior teeth come in irregularly, they rotate their way into place. These facts indicate that when nature is assisted, whether by mechanical devices or the removal of obstruc- tions, the regulation of malpositions becomes both simple and logical : and, furthermore,, that after regulation, the teeth 7; IRREGULARITII> <-l THK TEKTH. innv IM- firmly retained in their relatively new positions in tin- alveolar |.r<.eess. It -land- tii iva-oii that tlie application of light, constant pivs-ure t< irregular teeth, in connection with nature'- own efforts, will greatly enhance the physiological phenomena of absorption and reproduction of hone. Whether these phe- nomena will jiroeeed equally or not will depend npon the amount of pressure exerted and the condition of the individ- ual, for it is olivioiis that in cachexia- of various kinds disintegration is favored, while tissue-building is correspond- ingly sln^ish. This will serve to impress the immediately vital importance of the degree of jiressure and the constitu- tional condition of the patient in various operation- of regu- lating. When the whole of the alveolar arch i> -pr-ad later- allv. and the force is distributed fora distance upon both side- of the jaw, the hones yield to a certain extent, thus spacing the teeth equally in all directions; and by ah-orp- tion of the old and deposition of the new bone about them, they heroine fixed in their new positions. The degr< absorption and change of position is not always equal in all part- of the same tooth, varying chiefly with the direction of the pressure. When force is applied to the crown, and the tooth has to he moved considerably, there is more absorption at the margin of the alveolus than at its apex. Simple leverage will explain this: the mechanical appliance is the power, and the apex of the tooth is the fulcrum : naturally, the pow.-r acts up-ure i- too great, then absorption is arrested, n account of the inflammation ami pain which result. The operator -hotild avoid causing pain, and this is usually |>o<-ihle. When paindoesoecur.it should warn him that PART II TREATMENT. 77 the line of demarcation between physiological and patho- logical changes is being transgressed by mechanical violence. If the pressure be gentle, evenly distributed and constant, no pain will be experienced after the teeth have once begun to yield in the proper direction. But when the force is applied, removed, and reapplied at spasmodic intervals, con- siderable pain must necessarily result. The difference between the effects of steady and those of intermittent pressure is illustrated in every-day practice: where teeth have been separated to facilitate the filling of proximate cavities, the vibration of the teeth caused by preparing the cavity and applying the gold produces intense pain, which is relieved by inserting a wedge to distend and steady the teeth by its constant and equable pressure. Indi- vidual susceptibility must not be forgotten in this connec- tion ; for, as is well known, the impressibility to pain and the power of endurance vary with the temperament and condition of the patient. After the age of twenty-five or six the bones contain more of the earthy and less of the animal matter than during the formative and developmental period, and the constructive stage having passed, it becomes more difficult to move the teeth than in earlier life; and, pari passu, with the increased pressure required to effect absorption, a greater degree of pain and inflammation is produced. In these latter cases of regulating, retentive plates must often be worn, after the malposition of the teeth has been corrected, for two or three years, until a deposition of bone takes place which is sufficiently firm to hold the teeth securely in place. The teeth most difficult to retain are those that have been rotated in the jaw, as they have a tendency to return to their original and faulty positions even after a lapse of three years. By dispensing with the retentive plate for a day or two, and then reinserting it, any deviation in position can be readily noted. 7> IRREGULARITIES OF THE TEETH. EXAMINATION OF THE TEETH. When an abnormal condition of the jaw and teeth is pre- sented for examination, the nicest discernment is necessary to decide tin- best course of regulating. A dentist pn-sed with ordinary intelligence has no difficulty in correcting an insularity when a few teeth are out of position, but when tin- jaw- ami teeth are both involved, and the features are atlected thereby, the question becomes one in which judg- ment is necessary. That dentists are rarely able to cono much improved that there is no excuse for allowing deformities to remain, even though they be inherited. Speech is often interfered with by the contraction of the jaws. The upper or lower jaw, or both, may be so narrow at the bicuspid region that the tongue is forced into the fauces. The roof of the mouth may be high and narrow or flat and shallow; the natural or supernumerary teeth may point in such a direction that the tongue cannot move pro- perly. The incisors may be so separated, or the teeth may be so proportionately small, as to produce spaces >utlieicnt to affect the speech. DECAY OF THE TEETH. In frail, anemic patients, it is often wise to extract a tooth from either side of the jaws, when the teeth are crowded and decay is rapidly going on between them. Which tooth to PART II TREATMENT. 79 remove will depend upon circumstances. Those most decayed or nearest the deformity are the ones to be removed. If a molar be badly decayed upon one side and a bicuspid upon the other, they should be removed. The condition of the teeth must, to a great extent, govern the operation. The dentist must decide in each particular case. OCCLUSION. While the model is the surest and easiest means of study- ing the occlusion of the teeth, the final conclusions can be drawn from the mouth; hence this part of the subject will be taken up here. It has been shown how the teeth, which are nearly always normal in size, work their way through the jaws and arrange themselves along the alveolar process. These teeth developing individually, it would be natural to expect that in occluding, the cusps of the teeth upon one jaw would not fit into the spaces in the teeth of the opposite jaw. This being the case, owing to the constructive stage of the alveolar process, the teeth will arrange themselves to conform to the articulation of the opposite teeth. The teeth all being in the jaws, and the mesial and distal surfaces of all the teeth touching, if the articulation be not perfect the teeth will rotate in their sockets. If spaces exist between the teeth, they will change their position until the proper occlusion is obtained. We sometimes find the buccal cusp of one tooth striking the buccal or lingual cusp of the tooth opposite. In such cases one or the other is deflected in or out of the mouth. To correct these cases it may be necessary to extract a tooth, or cut away a cusp or the approximal surfaces of the teeth in order to cause occlusion. Lastly, an examination should be made of the shape and contour of the jaws, the height of the arch, and the inclination of the teeth, to decide upon a suitable impression cup and the best material for taking impressions. 80 IRREGULARITIES OF THE TEETH. FEES. In most cases an important consideration in the operation Dilating u net of teeth is the pecuniary reward for it. Tin- specialist in this particular branch should lia prepared himself that hr will fully understand and appreci- ate the requirements of any case which he may undertake to correct. To do this will take much time and anxious thought, for which he should receive a just reward. A thor- ough understanding as to the proper remuneration for the operation should he estahlished between the dentist and his patient before anything is done. The models of the jaws should be carefully examined. The temperament and disposition of the patient, as well as the ossific condition of the jaws, should be considered and minutely inquired into. For it will frequently happen that mouths exhibiting very nearly the same deformity will, on account of mental and physiological idiosyncrasies and great difference in density of tissue, require very different treat- ment in order to accomplish equally favorable results. After these preliminaries have been carefully attended to. a< c,.r- reet an estimate as possible should be made (and at the best it can but approximate) of the expense of regulating the teeth and securing them in their proper position. At this juncture, and before any operation is begun, a thorough understanding should be established between the operator and the parent or guardian of the approximat- of the work. It is well not to be too definite in regard to the matter; for it will frequently happen that the operation will require very different appliances and consume more time than was at first anticipated, in which case the operator should be rewarded for his unexpected labor. Or, the oj .era- tion may be completed in a much shorter time than was anticipated, in which event a proper regard for the patient's rights should prompt a reduction in the fee. A minimum and a maximum price, therefore, should be agreed upon before the operation is undertaken. Conspicuous among the difficulties which come with regulating is, first, to persuade PART II TREATMENT. 81 the patient to submit to the annoyance of wearing the appliance ; and, secondly, to impress upon the patient the necessity of being prompt and faithful in his visits to the dentist. Not appreciating the importance of these opera- tions, patients, and especially children, frequently become discouraged, and are anxious to abandon the treatment be- fore it is completed. The parent too often sympathizes with the child, and without regard for the labor or expense which the dentist has assumed, or the real interest of the patient, the operation is abandoned. The dentist is left without remuneration, although up to this point he has carried out his part of the contract. To secure the continued coopera- tion of the patient and parent until the completion of the operations, it is but justice to the dentist that he should demand and receive at least one-half of the proposed fee before the work is begun. With this money invested in the operation, the parent will be loth to allow the case to be abandoned before it is finished. The dentist should, with due regard to the comfort and good of his patient, do all in his power to expedite his operation, so that the suffering and expense may be as light as possible ; but whatever he does should be done with an in- telligent understanding of the physiological and pathological conditions with which he is dealing. The patient should, by obedience to the dentist's instructions, do all in his power to facilitate the correction, which will, as a matter of course, greatly reduce the expense of the operation.' As a rule, it will be better not to be too minute in detailing the plans intended to be followed and the appliances to be used in the course of the operation, for it will frequently happen that the most carefully-planned procedure will have to be varied during the operation; in which case disappointment and dissatisfaction might be engendered in the mind of the patient, and lead to a suspicion as to the dentist's ability to accomplish the results at first promised. CHAFfER II. I.MI'UKSSinNS <)F THE MOUTH, AND MODELS. Taking the impression of the mouth and jaws is, of necessity, the first step in regulating the teeth. To secure a counterpart of tin- mouth sufficiently accurate for reference and study, so that when a model is examined it will show \act contour of the irregularity, requires much can, The |>osition of the teeth, their relations to one another, and the conformation of the jaws can be more easily studied, and accurate conclusions more readily deduced, from the cast than from an examination of the mouth itself. It is not only essential that the teeth should be moved to their proper places, hut they must be in harmonious relation- to one another; otherwise, they will be inclined to return to their faulty positions: and their normal relations can best be determined by studying the model. Impressions may be taken in plaster-of-Paris or in model- ing compound, but the material employed should depend to a great degree upon the shape of the jaw and the position of the teeth. If the teeth are but slightly irregular, or if the crowns are short and quite irregular, plaster-of-Paris should be used, as it can be removed from the mouth with but little disturbance of the impression. If, on the other hand, the teeth are irregular and long, and the arch deep, plaster-of-Paris w r ill be apt to adhere to the teeth; in this event only the impression cup will come away, and, as a consequence, the plaster will have to be cut out. In such cases the modeling compound should be used. Where the plaster is used the patient should occupy an ordinary chair instead of the operating chair, as the head is lower and the operator can have better control of the patient. Protect the clothing by placing two towels under the chin and a newspaper in the lap. Select an impression cup 82 PART II TREATMENT. 83 enough to enclose the teeth, and build it up with wax so that it will extend beyond the margin of the gums ; fill the centre of the cup with soft wax to conform to the palate ; and the plaster will be readily carried to all parts of the mouth. Take a quantity of the finest quality of plaster, and mix it in a bowl with sufficient water to make a mixture of the consistency of thick cream ; the addition of a little salt will hasten the process of setting. After stirring until the air bubbles have disappeared and the plaster has begun to set, fill the cup and outer edges with it. The operator should stand to the right of and just behind the patient, with the left arm around the left side of the head, and the forefinger inserted into the mouth. Carry the cup to the mouth, with the thumb and forefinger upon the handle and the middle finger in the centre to steady it, and after it has been inserted into the mouth, with a rotary motion of the right hand press it into place, at the same time raising the lip and pressing out the cheek with the left finger. When the cup is in position, hold it firmly with the middle finger in the centre of the plate against the teeth. Incline the head towards the breast to prevent the plaster passing back to the fauces. Should the stomach become disturbed, and vomiting ensue, it can be evacuated without interfering with the impression. Test the plaster in the bowl or on the impression cup, and when it will break with a clean fracture, it is time to remove the cup, which can be done by moving the cup backward and forward with the right hand, and pushing out the cheek with the fingers of the left hand to admit the air. Having placed it in the upper towel, held up by the assist- ant, carefully examine the mouth, and if pieces of plaster are seen, put them in the towel on the proper side of the impression to save time, and set it carefully away, after- wards arranging the pieces in their right places in the impression. The second towel is for the purpose of removing plaster that may remain about the face. 84 IRREGULARITIES OF THE TEETH. It is well to explain something of the operation to the patient. ;is one would naturally anticipate a miv serious experience than is actually realized. All of these little de- tails should he strictly attended to, in order to insure a per- fect impression at the first sitting, and thus save the patient the annoyance of several applications. In taking impressions of the lower jaw, the patient should Mt higher, so that the mouth will he on a level with the rlhow of the operator, who stands in front of the patient: the fingers of the left hand should push out the cheeks and lips while the cup is rotated into place with the ri-ht hand. The first and second finger of each hand should iv- 1 upon the cup over the bicuspids and molars, the thumhs under the jaw on either side, thus holding the cup firmly in place until the plaster sets, when it should he removed and placed in the towel as before. After a few minutes' hardening, the impression should be placed under running water to remove mucus, saliva, blood or particles <.f plaster. Should the plaster he broken, the piece can l.e placed in the positions indicated by the arrangement on the towel. and. when perfectly dry. fastened together by melted black wax. A clean separation of the model is obtained by covering it with a lather of soap and washing off the Mirpliis, or by coating with shellac and oiling to prevent sticking. The author has used modeling compound with success by heating it in warm water until it is of the consistency of soft dough and placing it in a warmed impression cup in such a manner that it will cover all parts of the teeth and jaws when it is forced into place. The impression cup should be held firmly in place fora moment, and a towel >aturated with cold water should be carried to all parts of the mouth to chill the compound. S. S. White's upper and lower impr sion cups. Xo. 17 and 18, such as are illustrated in Figs. 38 and 39, should be used in taking impressions in cases of irregularities. It is a good plan to oil the surface of the impression, thus preventing the compound sticking to the cast. PART II TREATMENT. 85 To obtain the model, place a sufficient quantity of water in a bowl and pour in plaster, allowing it to settle, and thus preventing the formation of air bubbles ; add enough plaster to make it of the consistency of cream. Put a drop of water into each depression made by the teeth in the impression, to exclude the air, and add a small additional quantity of plas- ter. By tapping the cup upon the bench the plaster will fill up the depressions without the formation of air bubbles ; FIG. the surface should now be covered with plaster, and after mixing in more dry plaster to make it thicken, fill the impression full and place it upside down on a glass slide. Now build out the model until even with the impression cup, and allow it to harden. It is better to let it stand from twelve to twenty -four hours, that it may become thoroughly- hardened before being removed. 86 IRREGULARITIES OF THE TEETH. Having ivm the first permanent molars. If space be wanting, the question will arise whether to enlarge the arch by force, or to extract one or more teeth, and thus give the required room. The age of the patient will to a certain extent decide this question. If the temporary teeth are in the mouth, causing irregularities, they must he removed. When the removal of the second teeth becomes a necessity, a tooth should be selected which is the least prominent or which will least affect the expression. A good rule i- to retain, it' possible, the six anterior teeth. As the cuspids are the most prominent and give expression to the face, they should never be removed ; but if one must be sacrificed, the selection lies between the first or second bicuspid and the first molar. If we find on examination that the teeth are decayed (at the a ire of twelve or thirteen years it is common to find the lir-t permanent molar decayed), those affected should he extracted if the crowns are wholly or partially destroyed. In the model of the upper teeth of a girl fourteen year- of . (Fig. 47), the bicuspids are seen to have advanced -o far forward that there is insufficient space for the cuspid to come down into place. Upon examination of this case it wa- foimd that the first bicuspid upon the left side and the first nanent molar upon the right side were badly decayed. It was easy to decide which teeth should be sacrificed. The PART II TREATMENT. 91 cuspid upon the left side came into place without assistance. The bicuspids upon the right side were carried back and the right cuspid came into place. It is probable that in the past the first permanent molar has often been extracted without sufficient cause. As this tooth serves an important purpose in mastication on account of its broad surface, I should advise its retention if the crown be in a fair state of preser r vation. It has served for six years, which fact, in connec- tion with its solidity in the jaws and its central position, is an argument in favor of keeping it as long as possible. Upon examining the models of the jaws, we occasionally find the articulation posterior to the cuspids perfect, with the Flfi. 47. cuspids nearly approximating the centrals, and the laterals locked inside of the arch. Whether they are sound or decayed, it may be best in such cases to remove one or both laterals. The general appearance of the teeth will not be injured by this treatment. Dr. Guilford, in the "American System of Dentistry," mentions two cases of this kind, as follows : " The writer had two cases in one year presented to him for the reduction of prominence in the superior front teeth. In each case there was a broken or badly-diseased right central that was past hope of redemption. In these cases it did not happen particularly amiss, for the extraction of the roots afforded room for drawing in the remaining five 92 IRREODLARITfES OF THE TEETH. teeth, thus easily mincing the deformity, and at tin- same time do-ing the -pace made by % t heir loss. Tin- appearance ( ,f tin- patient in each instance was greatly improved, and the al-ence of even so large a tooth as the rent ml was (scarcely noticeable. " In a n>t her case, a girl eleven years of age had lost a right superior central incisor through a fall from a swing. Two .lav- alter the accident, and when the tooth had been mislaid or thrown away, she was brought for treatment, Only two methods of remedying the difficulty suggested them>elves. One was the wearing of an artificial tooth, the other drawing thet.eth together to close the space. The latter plan was decided upon, and successfully carried into effect, but. unfor- tunately, as there had IHVH no protrusion formerly, and there Mitraction afterward, the superior teeth no longer over- lapped the lower ones, but met them edge to edge, thus giv- ing the upper jaw a flattened appearance which was in itself a deformity. The patient was saved the annoyance of wear- ing an artificial tooth, but her facial expression was injured in consequence." Irregularities of the inferior incisors are often seen, and if the articulation be normal in the posterior part of the mouth, almost any of the incisors that are out of position may be removed. They resemble one another so closely in size and shape and are so nearly concealed by the lip that their loss will not be observed. The author would suggest that tin- operator needs to be particularly careful in deciding upon the mode of treatment, as he has seen three ca-es in which an actual increase of thedeformity was produced by a hurried operation. In one of these, a girl ten years of age, a central inri.-nr was remove. 1. and the muscles of the lip. together with lateral pressure of the adjoining teeth pu>hrd against the cu-pids, forced the incisors into a crowded condition, pro-luring a V-shaped arch. It was ascertained that the articulation of the posterior teeth was not perfect. It has been advi-e.l |, v som,. authorities to remove a corresponding tooth on the opposite side where want of room compels the PART II TREATMENT. 93 removal of a tooth in the anterior part of the mouth. Thev claim that there is danger of the incisor moving by the median line when a tooth from one side only is extracted; but we have found that when a tooth is removed back of the canine, it is seldom that the lateral pressure is sufficient to materially move the incisors. In considering the bicuspids, the one which is the most decayed should be removed. If both are sound and it becomes necessary to extract one, then the first should be chosen. In studying a model, the end to be kept in view is the retention of the teeth in place after they have found their new position. It is very important that the occlusion of the bicuspids and molars should be such that when in position and properly articulated, they will hold one another in place. If this be not accomplished, the incline of the cusps will force the teeth into their original faulty positions. APPLICATION OF FORCE. In every appliance for regulating the teeth the object is the same, viz., to exert pressure upon the teeth to be moved. Any appliance for this purpose should be as small as is com- patible with effectiveness and strength. When possible, it should be so constructed that it can be applied inside of the arch in such a manner that it will not interfere with speech or mastication, and can be removed by the wearer for cleansing. It should give as little annoyance and pain as possible, and should not necessitate frequent visits to the dentist for its adjustment. Whether the teeth are to be forced out or drawn in, there are always to be considered a body to be moved (the tooth) and a fixed point of resistance. By studying the model carefully, the operator can determine the amount of force required to move the tooth, and select for the anchor- age of the appliance a suitable point opposite, which will more than resist the force required to move the tooth. This point may be one or more of the natural teeth, or a plate may be constructed for the purpose. In applying the appa- 94 IKllKOULARITIES OF THE TEETH. ratu- 1.. n t.M.th. its portion in the jaw should be observed, and tin- inclination of tin' root or roots must be ascertain! -.1 to ,1,.,-i.U- whether they stand perpendicularly in the alveolar Boron an incline. All obstructions should be removal by extraction (.r by lateral pressure. The I'm y length- en injj the rod proportionately or in combining the leverage with another I'm-re. Tin- application of an increased length of rod is limited, Fio. 51. l"f want of space in the mouth; for if above rather limited litnensions it interferes with the tongue or lips. We nvanahly use the lever in any case in whirl, the anterior rapenor teeth occlude inside of the inferior teeth, if the e presented early enough. It is always desirable to n these teeth as soon after their eruption as possible, / ,., ""' Ix'ny tissue hecome-s dense and hard Fig .11 this simple method. PART II TREATMENT. 99 The young patient should visit the dentist's office early in the forenoon, with the understanding that he is to remain all day. He must remain where the operator can see that the pressure is constant. A round piece of hard wood, wedge-shaped at one end, should be inserted between the teeth, the point resting upon the palatal surface of the superior tooth (which is the body to be removed), the stick resting upon the lower incisor (the fulcrum), and the force applied by the hand upon the lower end of the lever. With constant application of the force the tooth will occlude outside its opponent before the sitting is ended, and this new position will be maintained by the pressure of the lower teeth upon the upper until the new position has become permanent. THE PULLEY, WHEEL AND AXLE. The pulley is a wheel with a groove cut into its circum- ference, and is movable upon its axis. In mechanics the common term for pulley is sheave. The pulley or sheave is placed between the oblong blocks of wood through which the axis passes and supports the pulley in the centre. The cord passing around the pulley is called the tackle. The bucket and weight in the old-fashioned well illustrate the pulley. The wheel and axle is a modification of the pulley. The wheel is fastened securely to the axle, the weight is attached by a rope to the axle, and the power by a rope to the wheel or to handles fixed at right angles to its rim. The steering-gear of a vessel is an illustration of this kind of lever. The forces combined in this appliance can pro- duce but one result in its application to regulating, viz., the rotation of the teeth in their sockets. The crown and root represent the wheel and axle, the rubber band the power. Fig. 52 illustrates the rotation of a tooth by having a gold band with an arm fitted to the tooth, and a rubber band attached to the arm and stretched to the first bicuspid ; as the tooth rotates, the arm is bent at right angles to the band. This application of the wheel and axle will accomplish the rotation of the teeth in the 100 IRREGULARITIES OF THE TEETH. ises. The difficulty lies in the retention of the te,-th aft.T they have Keen forced into their proper ,n. The younger the patient the easier this will be accomplished. To retain them in place, an impression of the teeth is taken in modeling compound, and a model made therefrom. Bands of gold (Fig. 53) are made to fit the plaster teeth with flat- and round-nose pliers, and soldered upon their palatal surfaces. A piece of clasp gold is fitted to these bands and allowed to extend past the lateral incisors; it should then le remove< 1 and soldered, and its edges filed perfectly smooth, so as not to interfere with the tongue. The teeth to be i Fio. 54. enclosed by the band must be dried, and the l>and tilled with o\y phosphate of zinc and forced into place. as in fig. 54. THE INCLINED PLANK. The inclined plane is a slope or flat surface inclined to the hori/oii. on which weights maybe raised. It is called one of the mechanical powers, because by it a weight can In raised up an incline to a point to which it would be otherwise impossible to lift it. This force is of especial value in in which the nrch is to In- expanded by an appliance: under Mich circumstances the teeth exert an outward piv> friction is useful in retaining the wedge in its position. Wlu-n applied to the teeth, the wedge increases the diameter >f the arc of a circle in which the teeth are implanted. It i* usually made from a fine-grained wood orof India-rubber. It is a direct and positive tbive. and is very effective. Teeth with long roots which are set deep in the alveolar proce-. when the latter is dense and hard, are difficult to start with ordinary regulating appliances. In such cases the wedge is of great service. It will readily move one or two teeth, and not infrequently three will be influenced by its piv-suiv. Wedge- made from orange wood are found to be very viceal.le, as they can be readily reduced in si/e as the <. may ivijuire. When applied to the teeth, they become satu- rated with saliva, swell, and in so doing force the teeth apart. When a rubber wedge is used, we select one slightly larger than the space between the teeth, and by its elasticity the teeth are spread. The rubber wedge performs its work with IT rapidity, perhaps, but it causes more pain than the wooden wedge. Owing to the elasticity of the rubber, the teeth vibrate with each effort of mastication, whereas they would be held firmly by the wooden wedge. January lth, 1879, a woman, twenty-.-even years of . teacher by occupation, came to me for treatment. I'pon examination we found the Y-shaped arch, dense and hard, and removed the first bicuspid on the right side and the second bicuspid on the left side, securing a silver plate to the tiiM in.ilars. The bands extended around the eu^.ids. with a nut and ><-rew upon either side. Instead of drawing the cuspids hack into the spaces made vacant by the first bicus- pids, as we expected to do, the cuspids became the point of PART II TREATMENT. 105 resistance, and the bicuspids and molars upon the right side and the molars on the left side were brought forward into the spaces. As the incisor and cuspid teeth were the only point of resistance, the molars being all loose, we were puzzled how to proceed. We finally decided to use the incisors for the fixed point, and with the compound force of the screw and wedge (Fig. 59) carry the anterior teeth backward. A rubber plate was fitted to the roof of the mouth and about the teeth that were to remain stationary ; the edge was beveled where the screw was applied, to prevent this being forced against the gum. I secured a jack-screw of the proper length firmly to the cuspid upon the right side, allowing it FIG. 59. FIG. 60. to come in contact with the tooth I wished to move, the bicuspid of the opposite side (Fig. 60). When this was forced laterally sufficiently, I removed the nut on the end of the screw, and replaced it with a wedge, which was inserted between the bicuspid and the cuspid. The cuspid being firm, and inflammation having been already produced around the bicuspid, it yielded readily to the powerful pressure of the screw and wedge. When this had proceeded as far as possible, the wedge was removed and a thicker one sub- stituted. As soon as the tooth reached the molar it was secured to it by ligatures, and so held in place. We fastened 106 IRREGULARITIES OF THE TEETH. nifimJy to the cuspids and forced them later- v mil iMtammt'ion set in. Wedges were put upon u . 1 -f tin- -n,v. iK-ing inserted between the cusp,, s h, l.,ml in"-*. (Fig. 61). The laterals, being ; sokc a. ful.-nii.i-, and -the cuspids were easily forced into hliv The* were th.-n fastened by ligatures. To more tin- lateral incisors a short screw was employed, with wulp* in which holes had been drilled, n-ntral a li.n-n thread was tied and then carried around the | ttll .ml ow the end of the wedge on the screw, pan ! ; .:. FIG. 62. thrmijrh the holes and tied fast (Fig. 62). By turning the crew the laterals were not only forced outward, but were rotated in their sockets. When this was accomplished, a plate was fitted to retain the teeth in place and also to draw the tvntnils hark into the arch. This was done by running a piece of gold wire across the labial surfaces of the centrals, frniu which a rubber band was carried posteriorly to a loop in tlu- rubber plate. As soon as they reached the proper position, another plate was inserted, with a gold band passing f the teeth to hold them in place. PART II TREATMENT. 107 ELASTIC FORCE. Each of the six mechanical forces has its proper place in the art of regulating teeth, and when skillfully applied is an effective agent. The application of these forces, how- ever, is limited. In looking about* for effective powers wi- find that the force of elasticity as found in India-rubber and the spring of metals combines all that is necessary to render effective either the most rudimentary or the most intricate appliance. The simplicity of fhe application of this force makes it very desirable in dentistry. Elastic bands cut from French rubber tubing can be universally used, and are applicable to every case of irregularity of the teeth. There is a power in elasticity peculiarly adapted to the correction of irregularities, and which cannot be obtained by any of the forces previously mentioned, viz., a constant, equable pres- sure, which may be either increased or diminished by the application of larger or smaller bands. This constant pres- sure produces a rapid absorption of the bone which opposes the restoration of the tooth to its normal position. When the rubber bands are applied to the teeth, the point of resistance becomes a very important feature. The resistance must equal or exceed that of the body to be moved ; otherwise. the weaker will be moved by the stronger force. If a tooth upon one side be irregular, a tooth, or, if necessary, several teeth, at the opposite point must be selected to withstand the pressure of the tooth to be moved. This not only requires a thorough knowledge of the anatomy of the teeth and . but ability to judge the comparative resistance of each tc We once tried to draw by the gold band and screw po< right superior cuspid into the space made vacant by t of a first bicuspid. The point of resistance was the >. bicuspid and the first permanent molar. It was founc M ; turning the nut two or three days, that the molar had been drawn forward half the space instead ing the cuspid into the expected position When the rubber bands are employed in cases rec much force, it is generally a good plan to fit a rubber P fc I0g IRREGULARITIES OF THE TEETH. othetet-th and jaws, to which arms of rubber or gold are . - .!. / K^ r> from rubber dam, model of the teeth of a boy fourteen years of age. Kio. 63. Fio. 63. ! I FIG. 66. jaw occludes outside of the upper jaw. A plate with gold band attachment (Fig. 64) was made to fit the jaw, extend- ing from tho first bicuspids around the incisors and cuspids, separated from tlu-m by a distance of a <|unrh>r of an inch. 1-late was secured to the first molars and first lik-uspids. Robber-dam rings were fastened to the band and carried iiu-isors and cuspids. The teeth were in a short PART II TREATMENT. lflg time brought out in place, as illustrated in Fi* 65 n, between the central incisors. By this means the teeth a" readily brought mto their proper position, When moving teeth or twistmg them in their sockets by elastic bands, it is des,rable to start the teeth with wedges of wood or rubber FIG. 67. or with the jack-screw, to produce absorption of bone about the roots and make the resisting power less complicated when the bands are finally applied. Fig. 67 represents the model of the mouth of a woman twenty-six years of age. The central incisors diverge from the median line, and are also twisted in their sockets. Kul>- *ber bands were placed about the teeth to draw them together. The pressure required was so great that two bands, each one- fourth of an inch wide, with a linen ligature tied with a sur- geon's knot on the outside of the bands, were required. Even with this powerful force it took three weeks to bring the teeth 110 IRREGULARITIES OP THE TEETH. -ether. Having produced absorption of the alveolar pro- 2TSe teeth were easily rotated in their sockets m the "' AMnd Xtlnum was accurately fitted to the crown and eoldere.1 \ hH.k was made by inserting and soldering a fr,,,, an artificial tooth into a hole drilled in the labio- !litul angle of the band; this band was fastened upon the t,H.tli with oxyphosphate of zinc ; a band of rubber was then attached at one end to the hook, and at the other to a bicus- pid, the tooth being thus rotated into place. Another plan is to dry the tooth, coat it with sandarac varnish, and while moist to wind about it a strip, cut from rubber dam, three- Fio. 68. sixteenths of an inch wide and two inches long, with a string tie slip upward toward the gingival margin, this inay U ol.viated hy an attachment in the shape of a small hook reMinj; upon one of the teeth. The apparatus acts as a lever, the power being the elastic- ity <>f tin- bow spring, the fulcrum, the teeth used for anchor- age, and the resistance the tooth or teeth to be moved. Kul.U-r Lands may also be used as auxiliaries. This appliance is ingenious and possesses many advan- tages. It is claimed by the inventor that any form of irregu- larity can be successfully treated with it. Only one band is needed, and no impression of the mouth is required; being conijKsed entirely of incorruptible metal, it is easily and thoroughly cleansed, and without removal from the mouth. It can also be adjusted or tightened at any time without removal. It can he applied to either jaw with equal facility. The principal objection urged against this appliance is that the teeth used as fulcrums or attachments are some- times not sufficiently firm to resist the pressure they are required to sustain, and in that case will move before the tooth which is being operated upon. This could probably be obviated by attaching to more teeth. The construction must, of necessity, be accurate, and if made by the dentist, requires great nicety of workmanship. Hut all difficulties of this nature are banished by the fact that it can be obtained at the dental depots. THE FARRAR METHOD. the distinctive systems of apparatus for regulating the :hat devised by Dr. J. X. Farrar, of New York, was ong the first to be presented to the profession. It was PART II TREATMENT. 115 introduced by him about 1876. The principle upon which it operates is peculiar to the system, which is called by the inventor The Positive System." In all (or most) methods employed previously, the endeavor was to bring to bear upon the tooth or teeth to be moved a force that should be, so far as possible, continuous. Wedges, rubber bands, springs^ etc., even the inclined plane, are all examples of this con- tinuous force, which it is the endeavor to continue, in greater or less degree, from the beginning to the end of the operation. Dr. Farrar's system is peculiar in this, that he uses only FIG. 71. the screw as a power, which he considers to be the only force capable of being applied with a definite and positive result. His theory is that a tooth should be moved a certain distance, as far as it is safe or proper, at one push or thrust, and then retained immovable in that position for a certain length of time. By this means he claims that the tissues in front of the advancing tooth are compressed, and kept com- pressed to such a degree that absorption takes place readily and without inflammation, thus making place for the toot being moved, while at the same time a deposition of 116 IRREGULARITIES OF THE TEETH. takes place bthind the tooth, tending to retain it in its new position This, then, is the principle of the Farrar method : a pwitivr thrust to a known and definite extent, the tooth _ retained hy tin- appliance in the new position, and a ,.i ,,f |H rfect rest allowed to intervene before more force l- applied. The apparatus by which the results are accomplished is constructed of ls-carat gold. An illustration of this appli- ance is shown in Fig. 71. In all (f his appliances a screw is to be found, upon which tin- thn-ads an- cut sixty to the inch. The end of the screw is fittnl t<. IK- turned with a watch key (Fig. 72) ; one-half a turn twin- a day will move the tooth y^ of an inch a day, which rate of progress Dr. Farrar finds, by experiment, to be about th- maximum rapidity consistent with safety ; and he Flo. 72. claims that this will produce only a slight uneasiness or sense of tightness, and no pain. He also claims that patients may be easily instructed to turn the screw them- selves, and to regulate the pressure by the sense of tight- ness, thus saving many visits to the office and the time of the operator. THE BYRNES METHOD. v Byrnes, of Memphis, has devised a method of whieh is worthy of notice.* He uses thin gold D or 22 carats fine, the motive power being the force of the bands. No plates are used, the tong obtained upon such of the teeth as are fixed points having been determined, the ited are connected to them by means of a * *>ttal Coanos, May, 1886. PART II TREATMENT. 117 thin gold band. This is so manipulated as to form a spring or series of springs, so adjusted as to bear most pow- erfully on the misplaced tooth or teeth. For instance, in the case of a misplaced incisor, to be drawn inward, a con- tinuous band embracing the first molars on each side is fitted around the outside of the arch. With a dull-pointed instrument like a burnisher, the ribbon is then pressed into the interstices of the teeth over which it passes, thus forming it into a series of small springs. The incisor, being the most prominent point, will naturally be most affected by the pressure exerted by the springs, and in a short time it will be found to have moved away from the band, so that it is no longer affected by the tension of the springs. The apparatus is then removed, the ribbon is annealed, straightened, anc small piece cut out of it; the ends are soldered and replaced, and the band formed into a spring as befc This method is stated to be equally applicable \ simple and complex conditions Sometimes the band may be advantageously supplement,,! aids, as the insertion of a rubber wedge a part u-u r^T^r^s^; r ; SraSsss.Tjsr.tt H8 ^REGULARITIES OF THE TEETH. behind the band opposite to one of the int^ rice? ,h,.n being fetched, it can be worked to the desir.,1 POL vltrn the enda should be clipped off nitrate, a case treated and described by Dr. Urn* T!i.- iiti.-nt was a young lady of eighteen yea,-. whl> ha( , 1,,,, ih, ri-l.t superior central at the age of eleven. X vulrinif plati- ha.l IKM-II xv..rn fi.r three and a half years. Th- remaining upin-r anterior teeth had been forced out- : unti l ,l u . v st.KHl at an angle of forty-five degrees when .,,-n The lower incisors stood inside the arch, and the Chin WM cunM^uently wrinkled and upturned. The lips ,nt ix)ut, the mouth being what is termed peaked, the molars being the only teeth that occluded rly. Ki... 74- In treating this case, it was the object, 1st, to correct the " peakedness " by producing a broader and more oval arch ; K- n-liirtiiiii ..f tlie projecting teeth; 3d, the improve- ment .f (li. articulation, and 4th, the closure of the spacv caused by the loss of the central. The last was undertaken firet A ht-avy Land (Fig. 74) was used to force the cutting edges of the right central and left lateral together. A very thin narrow jr,,M l, ;m .l was then fitted to eml.nuv the neeks these Urth. and a wedge of wood was inserted on the side tlit- .-uttina c( i ges> causing the teeth to move vertically rard each oth, r. Another band (Fig. 75) was then con- to move the incisors backward, and was placed ition without removing the first. It embraced the PAET II TREATMENT. 119 cuspids and bicuspids on each side; the connecting band was pressed into the interstices, and rubber wedges inserted. The effect of this was not only to cause backward pressure upon the incisors, but an outward pressure on the cuspids and bicuspids. At the end of three weeks the work un- practically accomplished, and the fixture was replaced by that shown in Fig. 76, which completed the movement of the teeth, and acted as a retaining piece. The small hook counteracted the tendency to slip up toward the gum. The regulation of the lower teeth was begun soon after that of the upper jaw was completed, and was carried through in about three weeks. A band, shown in Fig. 77, was used, clasping the first molars, passing around the bicuspids and FIG 76. FIG. 77. behind the incisors. A wooden wedge was placed between the incisors and the band, and springs formed by pr< the latter into the interstices between the cuspids and pids In two weeks this apparatus was replaced by shown in Fig. 78. A little block of rubber under each c the rings, which rested upon the cuspids complete work in a week. The rings being pressed back to presen the ground already gained, the piece was worn as a * plate. The final result is shown in I Fig. 80 illustrates the teeth of a lady aged t^nn The lower cuspids closed in front of the upper theden sapientes were erupting into a crowded arch, and pu 110 IRREGULARITIES OF THE TEETH. Fio. 79. I : - . FIG 81. Fio. 82. PART JI TREATMENT. ]2l the lower cuspids still further forward. The first bicuspid* were extracted to make room, and the cuspids were n.ovr.l backward by means of a band, shown in Fig. 81, which embraced the first molar and cuspid. The molars \\. -n- capped to prevent occlusion, but the age of the patient pre- venting rapid movement, the bands were cut and tightened only twice a week. In ten weeks the work was completed Fig. 82 showing the appearance at the conclusion of tin- treatment. Fig. 83 shows the upper jaw of a lady aged twenty-two, who fell at the age of ten years, striking the superior teeth in such a way as to knock out the right lateral and dislocate the other incisors, the left central remaining at an angle of thirty -five degrees after its attachment was again renewed. The incisors were separated from each other, and the deform- ity much more marked than shown by the cut. Fig. 84 shows the appliance in position used by Dr. Byrnes in this case, by which the regulation was completed in eight sittings. The connecting band was crimped as shown, thus converting it into a series of springs. Fig. 85 was used in a case in which the right central overlapped the lateral. The springs were adjusted so as to turn the tooth, the wtartin-point. and gives thereby the greatest elasticity and 1,-n-th of arms. When necessary, the Ion- end of the wire ran In- bent with square-nose pliers to make it on the same plane with the other arm. Fig. 89 shows the coil spring. FIG. 89. The coil of the spring works on the same principle as the mainspring of an American watch, which between two jM.int> measure^ a uniform period of time. The extremities of the arms of the spring travel over a given space with like uniformity, which gives a mild, uniform pressure to the jaws anl uvth. The arms may be hent or cut at any length to suit the cast- in hand. They may be used in connection with a rul.U-r plate, or with bands of gold or platinum "'1 t., the teeth with oxyphosphate of zinc. With properly drilled in the plate or bands, and the arms itu-d into them, the spring will stay in position. When the >pring i, ,,.,! without a plate, it may be well to fasten the nre to some of the teeth to prevent its being swallowed. PART II TREATMENT. f the 12? in The following models of the mouth of a girl sixteen years f age were presented to the author by Dr. J. F. Austin, of FIO. no. Chicago. The right cuspid had encroached upon the lateral incisor to such an extent as to twist and force it out of posi- tion, leaving only about one-half the space necessary to FIO. 91. rotate the tooth into place. A plate was made to fit th.- mouth and teeth, and a coil spring inserted, with arm- meeting the cuspid and central incisor. The spring was IRREGULARITIES OF THE TEETH. ,,,n,l to tin- plate by a pin driven into the plate (Fig. 90) v the lateral j.n-un- of the spring the teeth were pushed .part, makin, * the teeth to be rotate,! into place .howi the tooth secured in position by the Magil retainer. >l'l;i:\I>IN<; THE DENTAL ARCH. On mi exact plusti-r model of the case to be regulated a thin, narmw vulcanite plate is formed, with a short vertical poll fixed, either before vulcanizing or afterward by drilling rally in tin- j.late pivading the dental arch that has !'.,. jily used by the author is illustrated in Fig. - ,,f a rubber plate made to fit the teeth and jaw. Tin- pljit.- i> then sawed lengthwise commencing at a point anterior ! the teeth to be moved; a hole is drilled at the jMiint \\heiv the slot stops, to prevent the arms breaking. At the extreme end holes are drilled to receive the spring. dju-t the plate press the arms together and drop the plate into plan-. Kiir. iH5 shows the plate out of the mouth. This can ! removed and inserted ad libitum by the patient. A form of dental irregularity very difficult to correct is Km. 9.1. FlO. 96. - ..: :ound when the cuspids are situated near or in contact with the eentrak while the laterals stand inside of the arch, and when the jaws are closed pass behind the inferior incisors. laterals are in near relations to each other, it is by Unary mean* well nin-i, impossible to interact upon them ''i'-nt pressure to force them apart; the space being B too short to admit a jack-screw. Fig 517 repreeente such a condition. The cut is made a* of a case in practice, the patient being a young eenycftM^ag^whoeame under my care in -Hperi,,r laterals were then only one-fourth of an PART II TREATMENT. firml xe Wll oxyphosphate of zinc. A , bent into the form shown by Fig. 98, the ends of ,,.,. being turned at a sharp angle and cut short as sec,, in ,1,, figure. The spring was then put in place, the arm ends entering the holes in the collars, and the curved arms found to be so osely conformed to the surface of the gums and palatine 3 that the fixture was no obstruction to occlusi.m. and yet could be easily sprung out of position for cleansing pur- FIG. 98. poses or for increasing the expansive power of the spring, by simply widening the lateral spread of the arms. Fig. 97 shows the progress made in four weeks' treatment. \Vhen the laterals had been moved past the sides of the centrals, they were by other means forced outward into line. KEGULATIXG INDIVIDUAL TEETH. To force out central and lateral incisors, 1 have fmind the following methods useful: Around the tooth to be in.\vd. and around the molars as nearly opposite the direct i..n the incisor is to travel as possible, fit platinum collars Solder cups upon the collars directly opposite and in line. Make a spring of piano-wire (Fig. 99), and spring i , t OF THE TEETH. Fio. 100. Fio. 101. Fio. 102. PART II TREATMENT. 133 the cups soldered upon the collars. In Fig. 100 the apj.!!:, is seen in place. Another method is to make a plate to fit the teeth, thick- ening it nearly to the cutting edge of the tooth to be mov ,1. arid drilling a hole through the thickened part. Dinvtly opposite, at some convenient point on the back part of the plate, drill another hole just deep enough to hold the spring in place (Fig. 101). If the hole in the thickened part be drilled in the proper place, the end of the spring will hit the tooth midway between its cutting edge and the margin of the gum. This spring is very effective. The pressure is constant, and the spring is readily removed for adjustment or. for any other purpose. We frequently find a single tooth situated inside the dental arch, and have trouble in contriving an apparatus suited to the correction of such an irregularity. The illustrations represent some simple appliances that have been thoroughly tested and found satisfactory, in that they do the work effectively, are easy of adjustment and removal, and may be readily cleansed. Fig. 102 illustrates a second inferior bicuspid of the right side, having a lingual presentation equal to one-half the thickness of the tooth inside of its normal position. cut also shows teeth in other malpositions, but for < present purpose these are not considered. For this case a thin, narrow, close-fitting vulcanite pla was made, and a hole was drilled through the mid the plate opposite the centre of the tooth to be movec the other side another hole was drilled, but not quite thn, the plate. A suitable spring (Fig. 103) was th,n ma* piano-wire, having a single coil, A, and the ends of 1 bent at about a right angle. One of these ends short to enter the corresponding hole m the 1 , at, other end, B, left long enough to go through the impinge on the lingual surface of the birusj, fulfeighth of an inch between ** arm of * the plate, as is clearly shown by Fig. 1 134 IRRKGUI.ARITIER OF THE TELTH. |-,th nmi". n B, of the same length, to pass tlirough the plat.- and impinge m the lingual surfaces of teeth upon QppOl in.') slmws an appliance for pulling out the central A FIG. 101. A An illustration of the manner of the articulation will he found in Fig. 17, page 35. A plate is innde to fit tin- jaw ami teeth, ami into it were vulcanized two of the TalUt springs at the lateral incisor region. The wire arms turnnl into loops at the extremities to secure a ligature. Fi... th,. pl.-.te was adjusted the arms were bent liori/cn- broughl inclose proximity to the lal.ial surfaces ntral in.-isors and securely tied. Hv this means ant pressure was appli,,!, and the teeth were carried outside of the inferior incisors. CHAPTER V. TREATMENT OF SPECIAL FORMS OF IRREGULARITIES. ROTATING TEETH IN THEIR SOCKETS. THE FARRAR METHOD. Dr. Farrar has devised for this purpose a modification of his "positive system," which is illustrated in the following cuts : Fro. 10R. FIG. 108. FIG. 107. A Figs. 106 and 107 represent screw-wrenches ma dr "f 1 carat gold, with the exception of the screw in I'V- I" 7 - which may be made of brass or steel, as dcsiivd. If tin- form represented in Fig. 106 be used, it is adjusted on t tooth, and the thin gold of which the band is compa made to hug it by tightening the nut, B, and the bar, F, resting firmly against the adjacent tooth : the nut once or twice a day causes the tooth to n the box-wrench (Fig. 107) be used, the arm acts u ,- to which is attached a band of rubber, and ligatun- a* to a firm tooth, as shown in Fig. 108. Or, both forms , 135 J36 IRREGULARITIES OF THE TEETH. be uacd.ns in Fig. I" 1 -'. ll>' P"^ r bein g obtained by a scivw nitiiiiiiu' in a ^vivrl. A', attached to a distant tooth. , in ..mil 111 show another form of apparatus, so siinjili- and so plainly shown by the cuts as to require little iption. The strip of plate resting on the palatal sur- feoea, of the adjoining teeth serves as a fulcrum, and the tooth operated on is rapidly drawn into line and rotated. 1 in represents an actual case treated by Dr. Farrar, and, ;, },. the patient, about thirty years of age, manipu- lated the apparatus himself, reporting only once during the week that the operation was in progress. Fig. 11- illustrates a right-angle key or wrench, with Level pinions similar to the right-angle engine attachments which Dr. Farrar uses for turning nuts in localities such as that shown in Fig. 110, or in other localities where it is dif- ficult to use the ordinary wrenches. l>r. Farrar's " triplex system " is also adapted to the treat- ment of cither of these varieties of irregularity, as illustrated in Fig. 113. "The bearings of the bands upon the different |M)ints of the teeth and the directions of their movement are indicated by the arrows, while the details of construction are shown in the figure, and the device is made as follows : A stitf strip of plate, T, is bent on a, form to loosely fit the necks of the teeth at certain points under the free margin of the jruins. and prevent the plate from slipping from the teeth; and the <-nds of the plate are so shaped as to bear firmly on the distal comers of both teeth. These bearings may be lian-rd l,y properly bending the ends of the plate as the "l-en.tion advances. The bridge, C, carries two rollers, H' n which the thin ribbon loop, /,, passes, and is 1 it< fold on a wire attachment to the middle of bar, shown in position on the tooth. The screw, S, is swiveli-d * tf end of the metallic ribbon loop, and screws into the '"'I- with the effect of separating the ends of the "'!' thus moves the bridge toward the bar and Mates both incisors. modifications of this device may be adapted to PART II TREATMENT. 137 *WI different presentations of this class of cases, the main thing to be kept in view being the points of bearing of the bri.l^ C, and the bar, T; for while the apparatus will work ^ FIG. 109. FIG. 110. FIG. 111. FIG. 112. FIG. 113. 10 JRRWJULARITIES OF THE TEETH. when the teeth have small necks, it is difficult of retention ui->n taiN-rng teeth. . . -, - i n nmeou^ a firmer hold on the teeth may be obtained l,v u ..air ..f narrow loops, the folds of which pass on either ,,,- )h( . l, ;ir . around the ends of a pin pass..,- through im d nmj.rtii.Li from the middle of the bar, as shown in I- ig. HI Tin- har thus made and connected is easily detached bribe pupae of bmding its arms to obtain rotative bear- in-:*. A key f..r turning the screw may be readily made fn.in an .\ravat<.r. shaped as shown at K, Fig. 114." THE (iriLKOBD METHOD. Dr. S. lUiuilford has devised a little fixture for correct- ing malposition- of the central incisors, shown in Figs. 115 and !!'. At-c'inling to his description, it is constructed as Km. 115. Fio. 116. follows: A piece of gold backing one-eighth of an inch wide and sufficiently long to extend along and a trifle ln-yund the palatal >urfai-es of the centrals, is bent to conform as closely as possible to their lingual surfaces, and forward so a> \<> -lightly clasp (lie disto-palatal angles, as shown at Fig. 1 17. To this are Mildi-n-d two strips cut from plate-scrap, u little narrower than the first pieee.jmd bent in the form of // and c 117 1. n-peetively. which are sufficiently long to extend ly over the anterior and posterior surfaces of the teeth. hem-: pruperly shaped to fit the model, their backs are -old.r.d t.MMherand to the part, as shown in Fig. 118. The part h r, which passes between the teeth, is ^1T reduced sufficiently with a file, or the teeth ^^^**s may be separate. 1 l,y wedging, to allow the insertion of the fixture. The labial part should rest against PART II TREATMENT. 139 the teeth just at or slightly above the most prominent part of the convexity, while the lingual portion should be near the gum, but not quite touching it. The slightly-mm-d ends will catch just above the little nodule usually found on the disto-palatal angle near the gum. Thus secured, it can- not be easily displaced. Bend the long palatal arms slightly toward the short labial ones daily, and spring them int.. position on the teeth. The elasticity of the gold, stiffen ut in uome cases it hi-nums necessary to move the whole root For this puqiose, although the power may be the same, yet it must IK- iiuuli' to act in a different manner. In ordinary moving of teeth, the power is at one end, the UKv at the other, while the fulcrum is in the middle <>i tin- tooth to be removed. This is illustrated in Fig. 121, vli.-iv r \< thr power, .F the fulcrum, and S the resistance. |M.\ver being continued, the teeth arc drawn in the tion indicated by the arrows, [7. The first effect of this movement, so far as the roots are concerned, will be to cause t< impinge against the septum B, at the point F, and PART II TREATMENT. J 41 also against the socket wall at the point 8. They will also separate from the sockets at the points A and C', as indicated by the arrows. If the force be continued in this diiv,-ti,, n until the points touch, as in Fig. 122, the lever is chan-:.-.! into one of another variety, in which the power is applied FIG. 123. between the fulcrum and the resistance (X, Fig. 122). Thus, the same power from the same apparatus acts in exactly the opposite manner, causing the roots to approach each otlu-r throughout their length (the fulcrum being at 0, Fig. ! FIG. 125. Fir,. 126. and leave the socket walls in the same manner. Fig. 1 shows the completion of the operation. The appliance used by Dr. Farrar in this open* shown in Figs. 125 and 126. " It is mad, up of I clamp band to draw the teeth together, and ft lock poi j ,-j lUUKGULARITIES OF THE TEETH. to hold rfrfdnaiy the cutting edges of the teeth; Imt while ,,.,,!, aw being drawn together, only the band portion ,,,! | H . wed on each extremity <>f a band made ..t lighl Hlll | .tron- n.lled win- is soldcn-d a nut, one of them being i \v nut Tli rough these nuts pa^e< a little gold screw, havimr a head titled to a watch key. Tin- main point to li.'.l.l in view in constructing this elanip portion is to insure a ( .|o,c iN-aring at the -ruin border, to prevent it from slipping ,,tr tin- teeth. The lock portion, for preventing the over- lapping of the crowns when the force is continued after the teeth have hc,-n brought in contact, is a simple device, easiest mad.- by U-nding a -mall piece of plate about one-<|iiarter of an inch xjuaiv. .r a little larger, trough-like, so as to fit the - of the teeth : to this is soldered at right angles another ,,f plate extending far up between the teeth nearly to the ..MUM : on the upper end of this is soldered, tran-\ eisely, alH.ut one-eighth of an inch of small tubing (smooth bore). through which passes the bolt of the clamp band and from which it is loosely suspended. This part (the trough por- tion) may be constructed skeleton-like, as shown by Fig. 1 _'". and is more easily kept clean. The clamp is first applied, the force being interniittingly applied two or more times a day. or every time the band loosens by the move- ment of the teeth : but this should never be powerful enough to eau-e pain. After the teeth are brought in contact or nearly .. the inm-h portion is added, and the force of the clamp hand continued until the roots are brought into the d position." FORCED ERUPTION OF THE TEETH. THE MATTESON METHOD. Mally a single impacted tooth in the jaw does not work its \\-ay.luwn sufficiently to occlude with its opposite t-H.th. or the incisors do not meet when the jaws are closed. Such teeth are to be treated so as to make them as nature ntended. Dr. A. K. Matteson, of Chicago, has been success- ful in using the following methods : A rubber plate was PART II TREATMENT. 143 made to cover the roof of the mouth and to fit the necks if the teeth closely, a French clock spring being adjustc.l with one end riveted into the central posterior part of the plate i 127) ; when the spring was inserted and forced up again-' plate, the distal end of the spring touched the necks of tin- teeth to be drawn out; ligatures were then fastened to tin- necks of the teeth, and the spring carried up to tin- pi ate ami fastened to the teeth. If the spring be sufficiently powerful, from two to four teeth may be operated upon at one time. The spring being movable upon the rivet in the plate, one tooth at a time can be erupted, and then the point of tin- spring may be turned to the next tooth. Fig 128 shows a similar appliance for erupting th- fyili on the lower jaw. Erupting teeth is u,,lik, jnyof ( regulating operations, as no pressure to produce " Zen tteral pressure has been removed.,!,. ,nild,,, ^ is sufficient to draw a tooth out of the pM - are conical and the pressure is diredcd away to instead of against it, THE AUTHOR'S METHOD. J44 IBRKcM I .AKITIES OF THE TEETH. n .,,tiv -f the space made l.y the missing tooth (Fig. 1'J'.'). Tin- hoi.-, wliirli i< smaller than the coil-wire spring, holds one arm of the spring. The other arm (ii})on the end of which a loop has been made) meets the neck of the tooth to be moved, and is there -mred with a ligature. It' the tooth lc imbedded in the alveolar process and a ligature cannot be bound to it, a platinum hand, with a hook sol- dered upon it, may be forced up under the gum and secured with ovvptio>phatc of zinc. Should this fail, as a last iv-ort a huh- may U- drilled into the crown, and an eyeholt fastened in with ceiii.-nt, to which a spring may be fastened with a ligature. If inure spring to the wire be required, the hole may IK- drilled in the plate at a longer distance from the (".til t<> !> moved, thus giving a greater sweep to the arm. CHAPTER VI. PROTRUDING TEETH. KINGSLEY'S CASE. The following case, with the accompanying illustrations is reported by Dr. Kingsley : Fig. 130 shows the condition of the teeth of a child of nine years of age, for which no -adequate cause could be given, as it was not hereditary nor the result of thunilt- sucking. Treatment was not begun until the patent \v;i< Fin. 130. when the had all - : - ..... , 46 ,KUF,-I I.AUITH- OF THE TEETH. forward and .-au^ht ,,n projecting spurs of the gold -Ina . FIR. 133. the result shown in Fig. 133. 148 IRREGULARITIES OF THE TEETH. FARRAR'S CASES. When tin- abnormal protrusion of the six upper front tit-tli i- v.-ry marked, the correction of the irregularity may rvi|iiire a ^renter degree of anchorage than is afforded by tin- interior terth. Dr. Farrar has devised an appjmitu.- to , cases, known as a "bridle apparatus," which is illustrated in Fig. 134. Tlii^ i- constructed as follows: "A gold strap of rolled \viiv, havini: a smooth nut on each end, is bent to conform to the anterior surface of the four or six front teeth, and so fastened 1 ! '- v n "' :l11 ^ "'' - ''lamp Viands on the posterior teeth, as shown in Kijr. 1:;."). T- prevent tliUhaml from slipping up toward the uuni "u^hs have I,,-,.,, tried, hut they collect food and injure the "He . more T pieces made to fit between the ll. FIG. 135. gold (about No. 12 gauge), that project t,,nvan _ ward, thence pointing toward the es <; '.',',',. * front band (Fig. 134). To preven fcj curved cheek-wire, one side of the) m flat, and the ferrule shaped to correspond a hammer; but this is seldom . , ,,, . ,. "In some cases, in '****" ' b ,,,,,-,,! to* of no-consideration, the cheek-wires u> b 100 IRKKJI'LARITIEB OF THE TEETH. to tli.- front l>anuter extremities of these check- win- an- .screw-cut for drag nuts, one modification of which bfltateated l.y K, 137. H \\iivs may be in two or more pieces, but as this W< "<**, which may crowd upon the W^ |^. of the mouth, it > much better to -m one piece, which, if l properly, PART II TREATMENT. J-j will arch from the cheek to the ear-ring without hein^ j n contact Avith the cheek. "In fact, my experience teaches me that the latter is much the better form. The screw extends through the holes in opposite sides of a small ring, which is caught on our ( ,f several hooks soldered to a much larger ring extending around the ear of the patient (Fig. 134). This lar^r ring (which is necessary to prevent interference with tin- ear) is fastened to inelastic straps extending around the hack of the head and held in place by other straps, as -hown. The loAver straps and ear-rings constitute the uneh" apparatus. The ear-rings should be about IAVO and a half by three inches in diameter, underlaid by soft leather or felt rings about one-quarter to one-half inch wide, to > r\ cushions to protect the skin. In order to have the-e ring- FIG. 138. FIG. 139. rest in their proper places around the ears, and \<> i-nmt the harness to bear equally, so as to prevent headache, tl several straps should be made capable of being tigfa loosened at will by means of buckles. -When the apparatus is in position, the firienda patients are instructed to tighten the posterior Uiu turn the nuts within the smaller rings da ily. is advised to call at the office once or tui.v a u the position of the teeth has changed suffic.enlv to 1 the front bands liable to slip off, the dm,t,,n should be changed by raising the nut ring from a 1- ' " on the ear-ring to one " to the profession by Dr. Fnrmr 152 iKUKca-I.AKITIES OF THE TEETH. s j,ts of bands of gold or platinum extending around flu molar- an-1 bicuspids upon cither side of the arch. A nut l.U-red UIN.II tlu- Imccal surfaces for carrying a long screw. A band of gold encircles the arch, and is secured by hooks Jm.lwuv between the rutting i-dgrs and mrks of the Lncisoi t.i-tli. The ends of the hand are bent at right angles, hav- ing hole- through the ends for the free movement of the acre**. The hands and teeth enclosed are the fixed point-. and by turning the screws twice a day the anterior teeth are nirri.il t-> the posterior part of the alveolus. This appliance rlaim- cleanliness and the advantage of being out of sight ta >trong (Niints for its recommendation to our use. Km. 140. - : PROTIM SION OF THE INFERIOR MAXILLA. ALLAN'S CASE. FIJI. 141 reprints a case of protrusion of the inferior :!ary treat. -d l,y Dr. George S. Allan, of New York. The irn-giilarity {.ertaining solely to the jaw, that alone "- 11 "I A brass plate was made to fit the chin, not with honked ends arranged so that the distance ''"'" -"uld he altered by pressing then, apart or A network was adjusted upon the head, having "" *ew attached foupligatofee ,,f onlinarv elastic opewtion proceeded rapidly, and at the end of PART II TREATMENT. loo cartilage METHODS OF EE T ENTION No element of regulating the teeth is more difficult ,ln, that of securing the teeth firmly after they have Jn fo Fro. 141. into their new positions. The inclination to ivtimi t<> tln-ir original places is increased when the teeth ;irc nmvfl t'a-ti-i- than the physiological process of filling in new material i- accomplished. Pressure of the lips and tongue exerts influ- ence in producing backward and lateral pressure UJKHI tin- teeth. The greatest help in this direction is t<> -> plan the operation, either by extraction or by inward or outward pressure (as the case requires), that when completed thr posterior teeth will occlude in such a manner that they will 11 |54 IKKKUITLARITIES OF THE TEETH. hold one another iii proper positions. Dr. Kinsley, in his 1 Defctmtties/'says: "The articulation of masticating ,,f iinu-h more importance than their number, and a | mi j,,,| number of grinding teeth fitting closely on occlu- -i..n will l>e of tar -rivater benefit to the individual than a mouthful .f teeth with the articulation disturbed."* Occlusion, however, will not retain the anterior teeth in lotion. Nor will it be safe to depend entirely upon occlu- MIIII to hold th<- interior teeth in position. In most cases other menn< must be devised for holding the anterior teeth in iMisition. Cases of this kind are apt to be those in which th- an-h of the superior or inferior maxilla has been spread or the anterior teeth have been moved inward or outward. It i- then frequently necessary to spread both arches by -imply carrying the teeth of one jaw out to the proper dis- tance and M,-imi,,r ,}., w j t h a reten tion plate; the teeth of '!" "piH.sit,. jaw will in most cases be forced into their p. their grinding surfaces coming in contact in nms- "ation. Fig. 142 shows one of these retention plates. It J roof of the mouth and teeth accurately, and can be removed for cleansing. Such a plate is of service ither jaw for preventing one or all the teeth from back toward the inner part of the mouth. "/' "'/-, p. 43. PART II TREATMENT. loo KIXGSLEY'S RETAINER cation w,ll not serve when the teeth are crowded RICHARDSON'S RETAINERS. Where all the teeth in the jaw have been moved, particu- larly if some have been rotated into position, a retentive plate that comes in contact with all the teeth should be FIG. 143. used. A rubber plate will fit each tooth accurately without trouble or expense. Dr. Richardson gave his retentive plate to the profession many years ago, and in many respects it cannot be improved upon. Fig. 144 illustrate* this appli- ance. It is composed of two pieces of rubber, vulcanized upon the labial and lingual surfaces of the teeth of the plaster model. These are trimmed to about a quarter of an inch in width, and fitted to the necks of the teeth and gums. When a tooth is missing upon either side of the jaw, or when spaces exist between the teeth, or there is room In-hind the molars, the rubber may extend from the outer to the inner , M IRRBOO.ABITIE8 OF THE TEETH. I ihu< Hi'' two l' ieees >* mnde int " e ' K> "'* '" ! "",,, .'I, n , ,v te little or no room to carry the rabbet ";;;, ,* -ndgoM wire may " vuln... as to hold the w.n> in pos.tion. .,.,. ,,,, lv ,,l,j,Hi,.n . this appliance s its unsightly ap- ,,n.i..v It MB, however, I- iv"."v,,l by the patient for i;l l-.IU.i; ri.ATKS WITH GOLD BANDS AND BARS. When sinirle teeth have been rotated in their sockets, or in or out for the purpose of perfecting the contour, a , arrangement for retaining the teeth is to fit a rubber to the palatine or lingual surfaces of the teeth, and Vl... Flo. 14--,. attach a liar or clasp of gold to the teeth that have IKVM iuovcar attaclinl for holding the superior central incisors in their ixi-itioii after regulating. The bicuspids and molars may In- I -ituilarly. KuhU-r retainers are apt to be inconvenient for cleansing properly. Patients are inclined to be careless on this account. hut sliniiM In- instructed to attend to this duty after ea< li BMal to prevent the secretions from becoming vitiated, the JIUIIIH intlaiued. and the U-etli decayed. Great improvements these appliances have heen made in the past few years, as will W observed on examining some of the methods below. PART II TREATMENT. 157 FARRAR'S RETAINERS. Dr. FarrarX New York, has invented some in,,,,i,,u> Ap- pliances for holding teeth in proper positions, called - Retain mg or Anchor Clamps." Some are composed of one piece .,f gold, others of two pieces. Those having one piece ( I are made from square, 18-carat gold wire. This will '"takr a size to correspond with the tooth and the amount of reewt- ance required to hold it in place. A thread is rut fn,,,, one end to about a third of its length, the remainder of th.- win- is rolled or hammered into a thin band, about No. 35 .. American gauge, and about one twenty-fourth of an inch in breadth. At the distal end a hole is drilled, large enough to allow the screw end to pass through with a thread cut upon it. Small projections should be soldered upon tin- band and bent so as to catch upon the tooth. Wlu-n \\\- FIG. 146. FIG. 147. Ki.;. 148. pieces of gold are used, the band is made in the manner described in the first case, and bars of the same carat <. r "ll rolled to Nos. 22 and 23, American gauge. One end of Un- bar is bent to an angle of forty-five degrees to prevent tin- band from slipping. Near the other end of the bar a hole is drilled for the passage of the screw end of Fig. 147. Both bands may be used for rotating teeth in their sockets and also for retaining them in place. Fig. 148 show- I >v. Farrar's retaining band in position. DR. MAGILL'S BETA IN Ki;. Dr. Magill's retainer consists of a band of gold or plati- num (Fig. 149) swaged or fitted accurately to the tooth of sufficient strength to resist the rotary strain and fricti- mastication. By trimming the labial surfaces as narm IKKEOULARITIES OF THE TEETH. with strength, the band will not appear con- ,,,. It ^hould U' adjusted midway between the cutting iu.ling edges and the gum, and there cemented to the t.Hith with oxypli.xphate of zinc. This can be worn indefi- nitely without atfecting the gums or teeth, and can he cleansed perfectly: hence tin- hands, Lars or levers may be Fni. H9. FlO. 150. finnly >ol. It-red for rotating or retaining the teeth after regulating. Fig. 150 shows the application of one of these device-, when two teeth a iv secured in position by a bar ex- tending past fixed trrth on both sides. When two or m<>iv t.t-th an- to ! held in position, the Itands may be secured to the bicuspids or molars on both sides, and a bar of gold FIG. 151. d.-d from one to the other, upon the lingual or labial surface, as illustrated in Fig. 151, from Dr. Guilford's colh'.- " 1'latimim hands \veiv fitted to the two cuspids, and nnect.-d l,y a very thin platinum wire passing along and conform in- to the outline of the labial surface's of the 1 PART II TREATMENT. 159 THE AUTHOR'S RETAINER. This retainer consists of a band of platinum or gold titt-l .to the tooth or teeth, with a tube of the same material. th- width of the tooth, soldered lengthwise of the band, as illus- trated in Fig. 152. The band is fastened to the tooth with oxyphosphate of zinc, and a piece of gold, platinum or piano-wire is passed through the tube and allowed to come in contact with the surface of a firm tooth. Should the tooth that has been regu- lated move, the wire may be bent so that the tooth may be restored to its proper position. Two or more teeth may be retained in the same manner. The tube may be attached to the labial, buccal, palatine or lingual side of the band, according to the requirements of the case. LENGTH OF TIME REQUIRED TO RETAIN THE TEETH IX THEIR PLACE. Two reasons governing the time required to retain th- plate upon the teeth are, first, the age of the patient; ond, the nature of the operation. The time cam definitely stated for all persons, even of the same condition of case; an approximate period only can 1, In young and healthy persons, in whom reconstruct tissue is rapid, the retainer will be needed but a compavat, v, short time If the superior or inferior arches ha pids and molars. ],;,, IRREGULARITIES OF THE TEETH. T1,,- most difficult teeth to retain are those that have Urn rotated in their sockets. The difficulty of correcting tin- tendenev t" return to their original positions is so great that the retainers must be kept in place from one to t\v. years. a ,,,l ,,, -, -annually even longer than this. The operator will have t<> use his best judgment as to the proper time to remove them. The number of teeth being moved does not ; the time re. jui red, as the bone is as rapidly deposited in ,,ne part of the jaw as another. The health of the patient will have e..nsiderahle influence in the time required. A strong, ruliu-t person will recover from the operation more rapidly than one that is ana-mic. The retainer should remain as loin: as eiremnstamvs will warrant, when a model should be secure- 1. Alter the lapse of not longer than a day an exami- nation should be made. If the teeth have not deviated, a week may elapse before making another examination. Thaw examinations should be continued until the operator i-tied that the teeth are secure. If the teeth should move, the retainer must be replaced, and allowed to remain for from three to six months, when it can be removed and anv deviation noted. INDEX. Age, question of, in regulation, 73, 90. Allan's case of protruding lower jaw, 152. Alveolar plates, 17. process, absorption during regu- lation, 95. inferior, 18. superior, 17. processes, 36. Alveoli, 18. Alveolus, of temporary teeth, absorption of, 62. Antrum, 11, 12. Arch, dental, 27. spreading, 128. high, association with V-shaped and other arches, 58. - saddle-shaped, 51, 56. primary cause of, 57. typical, of American woman, 28. vaulted, 40. V-shaped, 41, 51, 92. Arches, of idiots, 68. Austin, 127. Axle, in regulating, 99. Ballard, 40. Bennett, 103. Bicuspids, 24. importance of occlusion ot, 89. irregularities of, 45. removal of, in regulating, 93. Black, 109. Bridle apparatus for protruding teeth, Byrnes' method of regulating, 116. Cartwright, 49, 53. Chinese, teeth of, 49. Coffin's method of regulating, 131. split plate method, 123. Coil spring, in regulating, 126. Coleman, 49. Coles, 53. Cooke, impression cups, 87. Crowns, 29, 38. moving, 140. Crypts, 37. Cuspids, 23. _ abnormal position of, 4,5. _ irregular eruption of, 44. Cuspids, irregularities of, 43. large, 33. temporary, extraction of, 63. importance of, 60. Decay of teeth, 78. Deformities, congenital and acquired, 51. from arrested dcvelopim-nt. 50, 52. Dentine, 21. Development, of jaws, arrested in i.lit-. 71. Down, 68, 71. Dwinell, 102. Elastic force, in regulating, 107. Elasticity of metals, 112. Enamel, 20. Eruption, of teeth, forced, 142. Matteson's method, 1 1:'. _ order of, 38. _ Talbot's method, 143. Expansion plate, Coffin's, ll'l. Extraction, early, irregularities from, 62. Farrar's cases of protruding teeth. 1 1-. method of moving crowns and roots, 141. _ of regulating, 114 _ _ of rotating teeth. retainers, 157. triplex system, 136. Fees, 80. Filling, of temporary teeth, 6J, OJ. Force, application of, 93. Guilford, 91. Guilford's method of rotating teeth. 1- Heredity, relation to irregularities, 45 Idiots, constitutional irregularities of, 69. _ irregularities of teeth of, 68. vaulted arch of, 40.^ Impression cups, 84, 85, 87 _ of lower ja" Impression* of mouth and jaws, 8. __ how to take, 82, 83. Incisors. -- central, 4-. _ pulling out, 134. inferior, irregularities of. 9- 161 1 ;_ lagton, lrr*jrulsriti of, 43. Utrl Ifi'lon*. firth of, 49. lrrl.nl INDEX. . , iutioni, of toon, 9. _ correction of, relation of gr to, 90. <-ti"l>'jry, SI- from arrested develop- ment, 50. _ contact, 45. _ _ early extraction, 02. retention of tem- porary molars, 60. retention of tem- porary teeth, 58. heredity ami, I >. rinniimt teeth, 33. of teeth of idiots, 68. of temporary teeth, HI. fpecial forms of, 135. Jaekferew, compound, 102. in rt>(fulntin>r. HC'. of Lee and IJennett, 103. Jaw, lower, impreMion of, 84. protrusion of, 68. pruirnat>p>iiv Mddle.haped, 56. dupe, changed by thumb-sucking, 41. *pper, protrusion of, 65. cause* of, fifi. Ja. contraction of, interfering with tpeeeb, 78. imprewiono. -:'. irregularitic* of, from arrested development, 50. of idioU, 69. Ktafdey. 53, 54. 6s. Stapler ' cam- of protruding teeth, 145. retainer for anterior teeth. IM. L*r, in refnlating and moving, 87. I.Klure, in regulating, 111. MeTullom, 102. children, jaws of, 71. Maiir, band. 111. Maon. . '! method of forced eruption, Maiilla, Inferior, 14. protrunion of, l.,j. Maxilla, inferior, protru.-i I. Allan's case, 152. superior, 9. Maxillary development, irrc^ulariiii-> Iron), 50. Mechanical forces in regulating, 97. Membrane, peridental, 20, 30. Metal*, elasticity of, 112. M iriorophalous children, jaws of. 7 I . Modeling compound impression-. M. Models, how to make, 85. mounting, 86. study of, 88. study of teeth by the, 79. Molare, 25. importance of occlusion of, 89. irregularities of, 45. temporary, causing irregulari- ties, 60. extraction, causing irregularities, 63. Mouth, impressions of, 82. Mummery, 49. Nichols, 49. Occlusion, 79. anterior, failure of, 65. not retaining anterior teeth. 154. Pain, in regulating, 76. Patrick method of regulating, 113. Piano-wire in regulating, 125. Plane, inclined, in regulating, 100. Plaster impressions, 82. Plates, retentive after regulation, 77. with gold bands, 156. Pressure, in regulation, 76. steady and intermittent, 77. Process, malar, 12. nasal, 12. palatine, 13. superior alveolar, 17. Pulley, in regulating, 99. Pulp of teeth, 21. Regulation, age for, 73, 90. application of force in. '.i:>. coil spring for, 126. elastic force in, 1117. inclined plane in, 100. jack-screw in, 102. late. 7 I . lever in, 97. lijra Mires in, 111. mechanical forces in, !7. methods of, 113. Byrnes', 116. Coffin's, 121. Farrar's, 111. Patrick's, IIM. Talbot's, 126. INDEX. 163 Regulation, of individual teeth, 131. piano-wire in, 125. pressure in, 76. proper time, 72. pulley, wheel and axle in, 99. rapid, 95. removal of teeth for, 90. retention of teeth after, 153. retentive plates after, 77. screw in, 101. wedge in, 104. Retainers, Farrar's, 157. Magill's, 157. Richardson's, 155. Talbot's, 159. Retention, length of time for, 159. of teeth after regulating, 153. plate, 154. prolonged, irregularities from, 58, 60, Richardson's retainers, 155. Roots, 29. moving, 140. Rotated teeth, difficulty of retaining, 160. Rotating teeth in sockets, 135. Rotation of teeth, 75. Farrar's method, 135. _ Guilford 138. Talbot's 139. Rubber bands, in regulating, 107. Saddle-shaped jaw, 56. Salter, 34. Screw, in regulating, 101. Septa, dental, 19. Shepard, 44. Speech, interfered with by contraction of jaws, 78. Stellwagen, 68. Talbot's method of forced eruption, 143. regulating, 126. rotating teeth, 139. retainer, 159. Teeth, absence of, 34. anatomy of, 20. anterior impression cups for, 87. arch of, 27. crowded and irregular, 90. Teeth, crowns of, 29, 38. cuspid, 4:'.. decay of, 7*. description of, 21. etiology, 31. examination < forced eruption of, 14L'. im-ixirs. 1L', 43. irregularities of, 33. occlusion of, 27. of idiots, irregularities of, 68. permanent, 20, 33, 34, 36. physiological changes of, "5. physiology of, 20. position of, 29. prehistoric, 36. protruding, 145. Farrar's case*, 14 v Kingsley's owe, 14.">. regulation of. See Jityulaliun. removal of, in regulating, 90. retention of, 58. after regulating. roots of, 29. rotated, difficult to retain, 160. rotating, in sockets, 135. - septa of, 19. sockets of, 18. supernumerary, 34. temporary, 20, 25. cleansing and filling of, 62, 63. extraction of, 39. _ _ irregu- larities from, 62. irregularities of, 33. time for removal of, 63. wisdom, 35. Thumb-sucking, 31, 40, 41, 56. and V-shaped arch, 53. Tomes, 34, 35. 38, 52. Van Marter, 36. Wedge, in regulating, 104. Wheel, in regulating, 99. White, 68. Wilmarth, 71. Winchell, 35. Wire, piano. 1L'.">. NOV BIO' orm L9-40-5,'67(H2161s8)4939