Oral Health Status, Knowledge, and Practices in an Amish Population


Vol. 48, N o .  3 .  Summer 1988 I47 

Oral Health Status, Knowledge, and Practices in an Amish 
Population 

Robert A. Bagramian, DDS, DrPH 
Chairman 

Sena Narendran, BDS, DDPH, MSc 
A. Mahyar Khavari 
Department of Prevention and Health Care 
School of Dentistry 
University of Michigan 
A n n  Arbor, MI 481 09-1 078 

Abstract 
This study was conducted in the summer of 1985 to 

assess the oral health status, knowledge, and practices 
of an Amish population in southwest Michigan. Dental 
caries experience, periodontal health, and oral hygiene 
status were recorded using decayed, missing, and 
filled surfaces (DMFS), periodontal index (PI), and sim- 
plified oral hygiene index (OHI-S). Data on oral health 
knowledge and practices were collected by interviews 
using a structured questionnaire. Results showed sig- 
nificantly lower levels of disease among Amish. DMFS 
scores for 5-1 7-year-old Amish children were almost 
half that of the US general population (NIDR 1979-80). 
PI score of all ages combined was 2.0, which was 3.6 
times lower than a national sample (1971-74). Lower 
levels of disease in Amish could be related to their way 
of life and dietary patterns. A relatively higher level of 
unmet need for prosthodontic care, inadequate oral 
health knowledge, and barriers to dental care in the 
study population emphasize the need for dental public 
health and health education programs. 

Key Words: Amish, caries, periodontal disease, oral 
hygiene, oral health knowledge, oral health practices 

The oral health of numerous contemporary a n d  in- 
digenous populations has been studied in different na- 
tions (1-11). These studies were both anthropological 
(1-3) a n d  epidemiologic (4-11) in nature. In the United 
States, national surveys d o n e  periodically have docu- 
mented the oral health o f  American citizens (11-13). 
Further, in the US the oral health of a group of native 
Americans, the Pima Indians, has been investigated 
recently (14-15). There is a lack of documentation of oral 
health status of the Amish population, which differs 
from the general population primarily in its life-style 
and dietary habits. Amish are a g r o u p  of settlers from 

Send correspondence and reprint requests to Dr. Bagramian. This 
paper was presented a t  the American Association for Dental Re- 
search annual meeting, March 12-15, 1986, Washington, DC. Manu- 
script received: 5/8/87; returned to authors for revision: 611 1/87; ac- 
cepted for publication: 4/18/88. 

northern Europe w h o  first arrived in the United States 
during the latter half of the 18th century (16). 

In the US, the Old Order Amish number over 75,000 
persons. Over 80 percent of the Amish population live 
in Pennsylvania, Ohio, a n d  Indiana; more than 50 per- 
cent of these live in the counties of Lancaster (Pennsyl- 
vania), Holmes (Ohio), a n d  Lagrange-Elkhart (Indiana) 
(17). The Amish settlement in southwestern Michigan 
constitutes approximately 2,000 people originally from 
northern Indiana. The Amish life-style is dependent o n  
farmland; settlers moved from lndiana to Michigan in 
the late 1970s in search of more available land at cheap- 
e r  cost. 

The unit of a n  Amish society is the church district, 
which is determined by the number o f  people who can 
be accommodated in a farmhouse for religious services 
a n d  h o w  far o n e  can travel conveniently by horse and 
buggy to attend. The districts are ruled over by lay 
clergy called bishops w h o  are chosen by l o t  (17). The 
present investigation appears to be the first oral health 
study of this g r o u p  (18-19). 

The association between diet a n d  dental caries has 
been well documented (20-22). The Amish have a 
unique life-style, generally abstaining from processed 
food items, a n d  relying o n  homegrown foods. Since a s  
much a s  80 percent or more o f  the sugar consumed in 
developed countries is in hidden form (23), i t  could be 
suggested that dietary habits of Amish might have a 
beneficial effect o n  their dental health. 

The purpose of this study was to assess (1) the oral 
health status of a selected Amish population, (2) their 
knowledge a n d  attitude to oral health, a n d  (3) their 
dental health behavior. 

Methods 
The study population was composed o f  121 subjects 

from 21 Amish families living in southwest Michigan. 
The local bishop was contacted concerning participa- 
tion in the study. Initially 26 families were contacted, of 
whom 21 (81%) agreed to be included in the study. The 
families contacted for the study were those within one 
church district in southwestern Michigan. Of the 21 
families that consented, all of the members present at 
the time of examination agreed to participate in the 



I48 Journal of Public Health Dentistry 

study. This sample may not be representative of the 
Amish population due to the small numbers of partici- 
pants in the study and potential selection bias. 

There were 68 subjects younger than 17 years of age 
with 37 males and 31 females, and 53 older than 17 
years of age including 25 males and 28 females. Dental 
examinations included caries experience, oral hygiene 
status, and periodontal health and were carried out in 
the summer of 1985 by an oral epidemiologist with the 
help of an experienced recorder. Dental examinations 
were conducted in natural light with subjects seated on 
a straight-back chair using a mouth mirror and No. 17 
explorer. 

Diagnostic criteria for dental caries were the same as 
those used by the National Institute of Dental Research, 
NIDR (11). Softness or definite break in continuity of 
enamel was a prerequisite for a tooth to be considered 
carious. Each tooth space was recorded only once. The 
reason for a missing tooth, either because of caries or 
for any other reason, was assigned by the examiner 
based on the caries experience of the respective subject. 
Wherever necessary, teeth were probed to confirm the 
presence or absence of dental caries. Radiographs were 
not used. Caries experience of each subject was record- 
ed using decayed, missing, and filled surfaces (DMFS). 

Periodontal disease status was assessed by applying 
the periodontal index (PI) of Russell (24), with criteria 
based on signs of periodontal inflammation, pocket 
formation, and loss of function. Each tooth in the 
mouth was scored; scores were totaled and then divid- 
ed by number of teeth present. This mean score repre- 
sents the periodontal condition of the teeth in the 
mouth. The PI was used in this study to allow compari- 
sons with existing national and international data. The 
mesiobuccal area of every permanent tooth was exam- 
ined for periodontal pockets using a modified probe, 
which has a 2 mm black band around the shank starting 
at 4 mm from the tip and ending at 6 mm from the tip. A 
score of four was given if the metal tip was no longer 
visible when the probe was inserted to the depth of the 
pocket and the black band remained visible. A score of 
six was given if both metal tip and the black band was 
submerged in the pocket. 

The simplified oral hygiene index (OHI-S) was ap- 
plied to measure oral hygiene status (25). OHI-S has 
two component parts, debris and calculus, each having 
a range of scores from zero to three. Six representative 
surfaces were scored in each mouth and a mean was 
derived for each person by dividing the total scores by 
six. 

Data on oral health knowledge and practices were 
collected by face-to-face interviews. A survey instru- 
ment was developed and pretested among family 
members of the Amish bishop ( n  = 7). The question- 
naire included 25 questions, four open-ended and 21 
precoded. The responses to open-ended questions 
were coded before the statistical analyses. The number 
of choices to precoded questions ranged from two to 
eight. Forty-eight percent of the questionnaires were 
related to oral health knowledge, 44 percent to dental 
health practices, and 8 percent to general items of inter- 

est such a s  sources of drinking water. The average time 
for the interviews was 18 minutes, with a range of 12 to 
27 minutes. 

Results 
Dental Caries. Caries experience ranged from 1.92 

DMFS for children under 11 years to 34.61 for adults 
over 35 years (Table 1). Approximately 25 percent of the 
population under 17 years was caries-free. Distribution 
of DMFS scores was not normal as indicated by relative- 
ly higher standard deviations. The finding of a higher 
standard deviation (compared to the mean) is often 
encountered in many epidemiologic studies following 
the recent decline in dental caries in children. The dis- 
tribution of DMFS scores by age and sex showed fe- 
males with higher scores than males in all groups ex- 
cept 18-24 years. Analysis by age group indicated that, 
with increasing age, contribution from decayed sur- 
faces (D) to DMFS scores remained constant, while 
those from missing (M) and filled surfaces (F) in- 
creased. 

Relative contributions of decayed (D), missing (M), 
and filled (F) to DMFS scores are shown in Table 2. The 
ratio of decayed D to DMF surfaces was 5.4 percent, 
indicating very little unmet needs of dental caries in 
this population. The MS/DMFS ratio of 46.5 percent 
reflects a high missing component, and also a high level 
of unmet need for prosthodontic care. The FS/DMFS 
ratio for the 5-17-year-old age group in the study popu- 
lation was 62.6 percent. 

Oral Hygiene Status. Oral hygiene scores ranged 
from 0.93 in children under 11 to 1.72 in adults over 35 
years. The OHI-S scores shown in Table 3 indicate a 
higher score for males compared to the females. There 
appears to be a typical decline in OHI-S scores around 
the time of puberty for both sexes followed by an in- 
crease in scores after age 25. 

TABLE 1 
Caries Experience (DMFS) by Age 

<11 
12-17 
18-24 
25-34 
35 + 

49 1.92? 3.99 
19 3.79 ? 4.83 
16 9.38 ? 6.99 
14 15.79 ? 8.18 
23 34.61 ? 19.33 

TABLE 2 
Ratios of Decayed, Missing, and Filled Surfaces to DMFS 

Status of 
Surface Mean?SD Ratio 

D 0.60?1.23 DS/DMFS (x 100) = 5.4% 
F 5.2956.77 FSlDMFS (x 100)=48.1% 
M 5.12'11.19 MS/DMFS (x 100) = 46.5% 
DMF 1 1.02 ? 15.60 - 



Vol. 48, N o .  3, Summer 1988 I49 

TABLE 3 
Mean OHI-S Scores by Age and Sex 

Males Females 

Age (yrs) n OHI-SkSD n OHI-S 2 SD 
~~ ~ ~~~ 

<11 5 0.9320.66 5 0.9320.15 
12-17 12 0.9320.74 7 0.8120.38 
18-24 7 0.81k0.39 9 0.72 -C 0.56 
25-34 8 1.48k0.85 6 0.75 2 0.76 
35 + 10 1.7220.51 13 1.0020.92 

TABLE 4 
Mean PI Scores by Age and Sex 

Males Females 

Age (yrs) n PI'SD n PI k SD 

<I1 5 0.05*0.11 5 0.11 k0.17 
12-17 12 0.24+0.22 7 0.09 * 0.09 
18-24 7 0.31k0.30 9 0.03f0.06 
25-34 8 0.23k0.20 6 0.26 f 0.33 
35 + 10 0.36k0.47 13 0.26e0.16 

Periodontal Health. Periodontal index scores for this 
population were consistently low, a s  shown in Table 4. 
Periodontal index scores increased with age from a low 
of 0.05 for children under 11 years of age to 0.36 for 
adults over 35. As with OHI-S scores, males generally 
had a higher PI than females. Of the 53 adults examined 
for periodontal pockets using a specially marked probe, 
only two subjects had periodontal pockets. One subject 
had two 4 mm pockets and the other had two pockets 
that were more than 5 mm deep. Both subjects were 
over 35 years of age. 

Dental Health Behavior. Almost two-thirds of this 
Amish population reported brushing their teeth less 
than once a day, while only 1.3 percent brushed twice 
or more a day; 2.6 percent reported never having 
brushed their teeth. 

Knowledge. In general, respondents exhibited inad- 
equate knowledge of the available preventive methods 
for dental diseases. An open-ended question on pre- 
vention of periodontal diseases showed that 73 percent 
of respondents were unaware of any preventive prac- 
tices for controlling periodontal disease. To a precoded 
question on prevention of dental caries, 55 percent 
agreed that fluoride is helpful in preventing tooth de- 
cay, while 26 percent did not know the beneficial role of 
fluoride. Almost all who agreed on the cariostatic role 
of fluoride, however, obtained this information from 
their dentists. 

Treatment Needs. The majority (61%) of the Amish 
in this study perceived themselves as possessing good 
dental health. Only 7 percent believed their teeth were 
in poor condition. About one-third of the population 
did not perceive themselves as having good dental 
health status and felt the need for dental treatment. 

Dental Visits. The study population appeared to 
consist mostly of irregular dental attenders. Among the 
respondents, more than one-third (35%) reported visit- 
ing a dentist every six months to one year, 19 percent 
visited every 12 to 24 months, and 46 percent visited 
less frequently than every two years. In other words, 
nearly half of the study population was made up of 
irregular attenders of dental care. 

Financial barriers seemed to be the most important 
factor for Amish not seeking dental care regularly. 
About 55 percent of the respondents felt dental services 
were expensive, 8 percent cited pain as a barrier to their 
being regular attenders, and availability of dental serv- 
ices was a problem for 6 percent. About one-third (31 
percent) did not perceive themselves as needing dental 
care. 

Discussion 
Given the poor oral hygiene status and lack of ade- 

quate knowledge concerning dental health and prac- 
tices, a s  well a s  existing barriers to seeking dental care, 
it was surprising that levels of dental diseases were so 
low in the Amish population. Such low levels of dental 
diseases could be explained by their dietary habits and 
possibly herd immunity (collective resistance to the dis- 
eases displayed by the community). 

A comparison of dental caries experience between 
the Amish and US children aged 5 1 7  (11,12) indicated 
DMFS scores of Amish children to be approximately 
one-half to one-third of non-Amish. Amish children in 
the present study had a DMFS score of 2.4, while non- 
Amish children of similar age groups had DMFS values 
of 7.1 in 1971-73 and 4.8 in 1979-80 (11,lZ). Some of the 
differences between the Amish and non-Amish may be 
explained by the secular decline in dental caries first 
evident in 1979-80 and probably continuing during the 
1980s. 

Low levels of dental caries found in Amish children 
could be attributed to infrequent snacking habits and 
consumption of sugar only at meal times. The latter 
concept is in agreement with the landmark Vipeholm 
study (20) on the association of sugar and dental caries. 
Amish homes d o  not have the usual food products such 
as prepared, precooked, frozen, and baked products 
that can be purchased in supermarkets. Although these 
families reported eating three large meals per day in- 
cluding dessert containing a large amount of sugar, 
they are not in the habit of constantly snacking between 
meals, like the general public. Analysis of well water 
revealed a low fluoride level, thus ruling out fluoride as 
a factor in low levels of dental caries seen in the 
population. 

The Amish d o  not purchase any type of health insur- 
ance plan, including dental insurance (16). Since their 
population consists primarily of irregular dental at- 
tenders, a high D/DMFS ratio, indicating unmet restor- 
ative needs, was expected in Amish children. O n  the 
contrary, the D/DMFS ratio was only 5 percent and the 
DMFS scores were mainly made u p  of missing (M) and 
filled (F) components. The F/DMFS ratio for 5-17-year- 
olds in this study was 62.6 percent, compared to 80.3 



I50 Journal of Public Health Dentistry 

percent in non-Amish children from NIDR Region 111 
(12). Factors such as financial barriers, lack of dental 
insurance, and availability of dental services might 
have contributed to the difference in the filled surface 
(FS) component of DMFS between these two groups. 

The low level of treatment needs for dental caries in 
the study population should be interpreted cautiously. 
This low D/DMFS ratio may be d u e  to a selection bias in 
the sample, with the dentally conscious Amish more 
likely to have consented to participate in the study. The 
high M component could also have contributed to the 
low D/DMFS ratio. A study on a larger scale is needed 
before this finding of low D/DMFS ratio can be general- 
ized to the entire Amish population. 

The relatively high M/DMFS ratio is similar to that of 
the New Zealand population that participated in the 
International Collaborative Study (8). The Amish, like 
New Zealanders, are predominantly farmers and face 
certain barriers to seeking dental care. They may be 
reluctant to invest their time in traveling, waiting, and 
receiving treatment. Also restorative care would in- 
volve follow-up visits for completion and replacement 
of restorations. Along with the time factor, financial 
barriers and a lack of availability of dental services 
might have contributed to the relatively high M/DMFS 
ratio. A high M component and edentulousness appear 
to be the social norm among New Zealanders, as seen 
in the International Collaborative Study. We are not 
certain whether the Amish possess similar social and 
cultural values; thus, there is a need for further re- 
search on sociological and cultural aspects of the Amish 
population. 

%Although these families reported eating 
three large meals per day, including 
dessert containing a large amount of 
sugar, they are not in the habit of 
constantly snacking between meals, 
like the general public." 

OHI-S scores of the Amish were higher than those of 
the non-Amish who participated in the NCHS survey 
of 1971-74. In addition, Caucasians aged 6 7 6  (1971-74) 
had 3.6 times (0.76 vs 0.21) higher mean PI scores than 
this study population (26). The high OHI-S and low PI 
scores suggest that certain features in the oral flora as 
well as the immune system of the Amish may be re- 
sponsible for their being less susceptible to periodontal 
diseases. The oral flora of the Amish should be a subject 
of further research. The finding that females in general 
have better oral hygiene and periodontal health status 
than males is not unique to this study. The small sam- 
ple size in the present study warrants caution in gener- 
alizing to the rest of the Amish population the finding 
of better oral hygiene and periodontal health in the 
Amish females than males. 

The lack of knowledge and attitudes concerning den- 
tal health can be attributed to the low level of literacy of 
the Amish. The Amish d o  not encourage education of 
their children, who only attend their own schools to the 
eighth grade. In addition, without electricity and tele- 
phones, there is relatively little communication with 
the outside world. The Amish have limited contact with 
the media since they d o  not possess radios o r  televi- 
sions. This study showed a high level of unmet need for 
prosthodontic care in the Amish population. Nearly 
one-half of those who participated in the study w e r e  
reported to be irregular attenders of dental care. All 
these factors indicate that a n  urgent need for dental 
public health programs-preventive, curative, and ed- 
ucational-for this population. 

This study is unique in that there has apparently 
been no documentation of dental health status in the 
Amish previously. This is d u e  primarily to the life-style 
of the Amish, who are reluctant to have contact with 
groups other than themselves and d o  not easily consent 
to participate in any study. Members of the Amish 
community d o  not wish to have their life-styles threat- 
ened by contact with the outside world. This is part of 
the basis for not having modern conveniences such a s  
electricity, radio, and TV. Access to the population was 
very difficult and required contact and discussions with 
the designated bishop of the community. 

Limitations of this study include small numbers of 
subjects and selection bias, which indicate the sample 
may not be representative. The conditions under which 
dental examinations were conducted limited the use of 
certain dental indices. Biases might also have been in- 
troduced by refusals and "non-contact" prior t o  the 
study as well as during the interviews. The lack of 
representativeness of the study population is often a 
limitation in such studies. A representative sample 
would entail not only a large investment of resources, 
but also cooperation of subjects, which may not be 
possible in a detached community such a s  the Amish. 

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