key: cord-0899632-o8vdb72g authors: Meriç, Pamir; Naoumova, Julia title: Did Covid-19 Pandemic Effect Orthodontic Treatment Outcome? A Clinical Evaluation Using the Objective Grading System (OGS) And Peer Assessment Rating (PAR) Index date: 2022-05-11 journal: Am J Orthod Dentofacial Orthop DOI: 10.1016/j.ajodo.2021.12.017 sha: 81668bb4cbb35d2820ee4769752ea8a431e74ee8 doc_id: 899632 cord_uid: o8vdb72g Objective The aim of this study was to compare the treatment outcome of patients whose orthodontic treatment was completed before or during the Covid-19 pandemic. Materials and Methods Pre-treatment (T0) and post-treatment (T1) models of 100 patients treated with fixed orthodontic appliances were evaluated using the peer assessment rating (PAR) index. Post-treatment models and panoramic radiographs were measured and scored with the objective grading system (OGS). All patients had their treatment plans made prior to Covid-19 pandemic but the orthodontic treatment finishing date was either before (Pre-pandemic: group 1, N=50) or during (Pandemic: group 2, N=50) the pandemic. Intergroup comparisons were tested with Independent samples-t test or Mann Whitney-U test. Chi-square test statistics and Fisher’s exact test were used for comparison of categorical variables. Results Significant higher post-treatment weighted maxillary alignment score was found in Group 2 (0 vs 0.2±0.5). However, no significant difference was found between the groups concerning the mean total weighted PAR reduction (29.8±9.9 vs 25.6±8.7) and post-treatment total weighted PAR scores (2±2.3 vs 2.7±4). The PAR index score improvement (%) was similar between the groups (93.7±7.1 vs 89.9±13). No statistically significant difference was found between the groups for the total OGS score (33.8±10.1 vs 34.2±10). A lower score for marginal ridge height (4.3±2 vs 3 ±2.3) and a higher score for buccolingual inclination (7.1±5 vs 10.7±4.5) and a lower score for occlusal relationship (3 vs 1) was found in group 2. Cancelled appointments (1.1±0.7 vs 4.8±1.6) and number of missed appointments (0.6±0.5 vs 1.1±0.8) were statistically higher in Group 2 while as total number of appointments (27.3±8.8 vs 21.8±5.4) were statistically less. The treatment duration was comparable in both groups. Conclusion Reduced and irregular appointments during the pandemic resulted in significant higher post-treatment weighted maxillary alignment and worsening of the buccolingual inclination. The PAR score improvement, total OGS score and treatment duration, however, was not affected. In December 2019, a pneumonia pandemic of unknown etiology occurred in Wuhan City, Hubei province, China. A new coronavirus was identified by Chinese Centre for Disease Control and Prevention as the cause and was named COVID-19 (Coronavirus Disease 2019) by the World Health Organization (WHO) 1, 2 . Observations suggest that individuals of all age groups are generally susceptible to COVID-19. However, individuals with confirmed cases or close contact with asymptomatic carriers, including healthcare workers and other patients in hospitals and/or clinics, have been reported to have a higher risk of infection 3 . The dentistry profession is among the risky occupational groups because of the aerosol and droplets splashes from the oral cavity, as it requires treatment at close proximity with patients 4, 5 . Since dental clinics are a risky area for Covid-19 transmission, routine dental procedures were suspended for a while except for emergency procedures 6 . Studies have revealed that although individuals undergoing orthodontic treatment know that the Covid-19 virus is dangerous, they are willing to continue the treatment not to prolong the treatment period 7 . Since orthodontic patients could not wait until the end of the pandemic due to the problems that might occur by prolongation of the treatment and the economic consequences made it necessary for orthodontic clinics to reopen after the permission of the authorities in the light of newly published guidelines. Poor oral hygiene 8 , reduced cooperation due to emotional stress 9 and decreased doctor-patient communication 10,11 are among factors that will negatively affect the outcome of orthodontic treatment. To minimize these problems during pandemic, it is recommended to maintain doctor-patient communication with teleorthodontics 12,13 and to keep in contact with the doctor by taking pictures or videos when necessary. However, not all orthodontic procedures can be controlled in this way and orthodontists were caught unprepared against a pandemic and each physician tried to help their patients according to their own conditions. Quality control in orthodontics is important to set goals, establish standards, achieve a measurable finish of treated cases and for educational purposes. Different quantitative indexes have been developed to evaluate dental malocclusion, orthodontic need, and treatment outcome. 14,15,16,17 One of these indexes is the peer assessment rating (PAR) index 17 which has been widely used to assess treatments objectively in a variety of circumstances 18,19,20 . The PAR is an occlusal index that measures how much a patient deviates from ideal occlusion by comparing J o u r n a l P r e -p r o o f pre-and post-treatment dental casts 17 . Each component of the PAR index is assigned with weightings to reflect their importance and to produce a weighting PAR index score 21 . A greater reduction in the mean percentage of the weighted PAR scores implicates that a greater degree of improvement i.e., success of the treatment is achieved 17 . The PAR index has shown excellent validity and reliability 22,23 , however, it is not a precise system that can be used to quantify tooth positions. Therefore, a more detailed index called Objective Grading System (OGS) was formed by the American Board of Orthodontics (ABO). The OGS index evaluates objectively post-treatment dental cast and panoramic radiographs. The final occlusion is assessed using eight different criteria. A lower score indicates a better final occlusion 24 . The devastating effects of the pandemic raises the question whether delayed and irregular appointments affect the treatment outcomes of patients receiving orthodontic treatment. The aim of this study was therefore, to compare the treatment outcome, using the PAR index and OGS, on patients whose orthodontic treatment was completed before or during the Covid-19 pandemic. The null hypothesis is that there are no differences between the post-treatment total weighted PAR scores or the OGS scores of orthodontic cases who were finished before or during the pandemic. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Research Ethics Committee of X University Faculty of Medicine (approval no. xxx). Study sample selection was made from 175 patients (pre-pandemic: 103, pandemic: 72) who met the inclusion criteria. Cases meeting the inclusion criteria were individually numbered within their group and then randomly selected using a web-based randomization tool (www.randomizer.org). One-hundred patients who finished their orthodontic treatment between 2019-2021 at the Department of Orthodontics, Faculty of Dentistry, X University were included in the study. The sample was divided into 2 groups: prescription braces. All cases were finished by the physician's decision. All 3D models were obtained by scanning plaster models. The impressions were taken with plastic tray using alginate material (Zetalgin, Zhermack Group, Rovigo, Italy) and poured with type IV gypsum (Fuji Rock; GC Europe). The plaster models were scanned by the Maestro 3D model scanner (AGE Solutions S.r.l., Italy) and transferred to the computer. Orthomodel v1.01 software was used for millimetric measurements. The screen used for measurement was 21.5" in size. The measurements were made on the digital models at 2-time points; T0 (pre-treatment) and T1 (post-treatment). The PAR comprised 8 components: maxillary alignment, mandibular alignment, antero-posterior, transversal, vertical, overjet, overbite and centreline measurement. British weightings (UK) were applied to the components described by Richmond et. al. 23 . The improvement in the PAR scores (success of treatment) are categorized as: 'greatly improved' if there is more than 22 point of reduction in the score; 'improved' if there is a percentage reduction of more than 30% and 'worse or no difference' if the reduction is less 30% in PAR score. For OGS measurements, post-treatment study casts and panoramic radiographs were scored. The first 7 criteria of the OGS index: alignment and rotation, marginal ridges, buccolingual inclination, overjet, occlusal contacts, occlusal relationship, interproximal contacts were measured on the study cast using ABO gauge and the root angulation was measured on panoramic radiographs as described by Casko et.al 24 . After a total number of case points was calculated which indicates the relative deviation from ideal. A case that lost more than 30 points J o u r n a l P r e -p r o o f will usually fail the ABO clinical examination while a case that lost less than 20 points will pass. A case that lost 20-30 points is considered as 'maybe' (borderline). The data were collected by a single researcher and the models were blindly assessed by another researcher (XY). The PAR index measurements were completed first, and after an interval of two months the OGS measurements were determined. The sample size was calculated based on a previous data in the literature 19 . A type I error of 0.05 and a power of 90%, a sample size of minimum 46 subjects per group would be required. G*Power software (Version 3.1.9.6) was used to calculate the sample size 25 . All statistical analyses were performed with IBM SPSS Statistics 25 (IBM; Armonk, NY, USA). The statistical significance level was taken as 0.05 in all tests. Normality of the data was assessed using the Shapiro-Wilk and Kolmogorov-Smirnov tests. Intergroup comparisons were tested with Independent samples-t test or Mann Whitney-U test according to the normality of the data. Chi-square test statistics and Fisher's exact test were used for comparison of categorical variables when appropriate. For the assessment of intra-examiner reliability, 30 randomly selected models were scored 2 weeks later, and intra-examiner reliability of the data was evaluated by intra-class correlation coefficient (ICC). Intra-examiner reliability was found excellent for total weighted PAR scores (ICC = 0.996; 0.992-0.998) and OGS scores (ICC = 0.968; 0.935-0.985). Sample characteristics for both groups are presented in Table I . Patients' age and gender, angle classification, treatment duration and extraction therapy were not statistically significant between the groups. Group 2 had significantly less appointments and more cancelled and missed appointments than Group 1 (p<0.001). Distribution of the subjects by total weighted PAR index scores pre-and-posttreatment and by OGS score are shown in Table IIa and Table IIb , respectively, showing no significant differences between the two groups. Number of failed, borderline and passed cases were similar in both groups (Table IIb) . PAR score reduction and improvement (%) between the groups are presented in Table III . The mean total weighted PAR score reduction was less in Group 2 compared to Group 1 (25.68.7 J o u r n a l P r e -p r o o f vs 29.89.9, p>0.05). No statistical differences were found regarding the mean improvement rate in percentage between the groups (93.77.1 vs 89.913, p>0.05). Pre-and post-treatment weighted PAR scores of the groups are shown in Table IV. The mean pre-treatment maxillary alignment, transversal and centerline was significantly lower for Group 2 compared to Group 1 (p<0.05). However, a statistically significant difference was not found between the groups for the mean pre-treatment total weighted PAR score (31.810.2 vs 28.28.2). There were also no statistically significant differences in mean post-treatment weighted PAR scores between the groups, except for maxillary alignment which had a higher score in Group 2 (p<0.05). In addition, the mean post-treatment total weighted PAR scores were similar: 22.3 for Group 1 and 2.74 for Group 2 (p>0.05). Table 5 shows the comparison of the OGS scores between the groups. Similar total OGS score was found in both groups (33.810.1 vs 34.210) with no statistically significant difference (p>0.05). The only significant differences between the groups were marginal ridge, buccolingual inclination, and occlusal relationship. A lower score for marginal ridge height was measured in group 2 which indicates that there are smaller or fewer height discrepancies between adjacent marginal ridges (4.32 vs 3 2.3) (p<0.05). A higher score for buccolingual inclination was found in group 2 (7.15 vs 10.74.5) (p<0.05), indicating worsening of the buccolingual inclination. A higher score for occlusal relationship was measured in group 1 (3 vs 1, p<0.05) indicating that posterior teeth deviated more from ideal anteroposterior position. The purpose of this study was to compare the treatment outcome of orthodontic patients whose treatment was finished before or during Covid-19 pandemic, using the PAR index and the OGS. The main finding of this investigation was that the pandemic and the lock-down did not affect the post-treatment total weighted PAR score even though significant high post-treatment weighted maxillary alignment score was found in Group 2. The total OGS score was also nonsignificant between the groups. The null hypothesis can therefore be accepted. Since the PAR index measures alignment components and occlusal improvement that is influenced mainly by initial orthodontic treatment phase, which in the current study occurred outside the Covid-19 pandemic period. Therefore, the OGS that is more stringent in assessing J o u r n a l P r e -p r o o f treatment outcome was additionally used. The total OGS score between the groups was found to be similar (Table IIb) and the only significant differences was measured in buccolingual inclination, occlusal relationship and marginal ridge. The buccolingual inclination is related to torque control in posterior teeth and high scores indicate deficiency in placing adequate torque in the buccal segments. Although the malocclusion distribution between the groups were similar, a possible explanation to the higher buccolingual inclination score might have been influenced by the higher number of Class II and III malocclusions in the pandemic group. Occlusal relationship measures the sagittal correction of the dentition and despite that the prepademic group had more CL I malocclusions, higher occlusal relationship scores were found in the pandemic group indicating a better sagittal dental relationship. Marginal ridge discrepancies are related to settling of the occlusion after treatment which might be a possible explanation for the lower scores since the models were taken at debanding, in contrast to the ABO that allows final models to be taken up to 1 year after debanding 26,27 . The degree of improvement or the success is in the PAR index reflected by the difference between the pre-and post-treatment. A score close to 0 means that the deviation from normal is less but since this is not always achievable, a measure of ≤ 5 suggests an almost ideal occlusion and ≤ 10 indicates an acceptable alignment 23 . In this study, similar mean post-treatment total weighted PAR scores were obtained between the two groups: 22.3 vs 2.74 (Table IV) , which indicates acceptable alignment and occlusion according to Richmond et. al. 23 . The mean total PAR score reduction was similar between groups and no statistical differences were found regarding the mean improvement rate in percentage between the groups: 93.77.1 % vs 89.913 % (Table III) . To the best of our knowledge, there are no studies comparing treatment outcomes of cases treated before and during the pandemic. Despite of that, the obtained results from the current study are consistent with previous studies assessing the PAR index differences pre-and post-treatment 20,28,29,30,31 . A reduction of 30% in weighted PAR scores is considered as significant improvement in the standard of an occlusion and a reduction of 22 weighted PAR points is considered as greatly improved 17 , while improvements smaller than 30% are declared as worse or no different. Majority of the cases in the present study were improved or greatly improved (Table III ), yet 54-58% failed the OGS and only 4% would pass with certainty. These results are in agreement with others who did not found a correlation between the PAR score and the OGS, implying that prediction from the OGS scores cannot be made for the possible percentage improvement in the PAR index 19,30 . A recent study conducted during the pandemic shows that over 1/3 of the orthodontic patients experienced mental distress. The level of anxiety was affected by multiple factors such as type of orthodontic appliance, time since the last check-up and communication with the orthodontist 32 . Several newly published studies report that the major concern for patients with ongoing orthodontic treatment during the pandemic was the anxiety over the treatment duration 32,33,34 . Furthermore, patients believe that their treatment was negatively affected by the Covid-19 pandemic since they thought that their treatment was delayed 35 . The present study found no differences in treatment duration between the groups, which was measured from the time to appliance were placed to the time it was removed ( Table I ). Factors that may influence the treatment duration include age, gender, severity of malocclusion, extractions and how experience the clinician is 36 . The current study shows that PAR reduction or total OGS score were not associated with treatment duration even though group 2 had significant fewer and irregular appointments and significant less total number of appointments (Table I) , raising the question of whether some control intervals can be partly replaced by: tele-orthodontics. Perhaps the effect of the pandemic will accelerate this new ergonomic approach and reduce the number of face-to-face appointments. Another future fundamental change in orthodontics might be the increased use of appliances and techniques requiring fewer visits and emergency appointments 37 . Significant more appointments that were cancelled by the clinic and by the patients were observed in group 2 which was a consequence caused by the pandemic situation (Table I) . Patients were unfortunately not contacted via tele-orthodontics, which has been shown to be of great value and should be a part of future clinical protocol as orthodontic treatment is an ongoing process that needs consistent evaluation and adjustments. Virtual triage is of great help to differentiate and prioritize orthodontic emergencies that needs immediate attention from problems that can be self-aided by a home remedy, i.e., minimizing unnecessary visits to the clinic. Furthermore, it is a good communication tool with the patient, facilitating instructions about oral health maintenance, insertion of elastics and motivation to continue usage of elastics. Routinely and direct communication with patients via tele-orthodontics has shown to give less anxiety compared to patients who got notices from web sites or from other patients 38 . To overcome potential biases associated with matching cases based on only angle classification 39, 40 , patients in the present study were randomly selected from a consecutive sample that proved to be heterogeneous in terms of initial sagittal malocclusion, gender, age and extraction therapy (Table I) . Many different indices are mentioned in the literature, and every index has its advantages and disadvantages 14, 15, 16, 17, 41, 42 . The PAR index and OGS were chosen in this study since they have been extensively used in previous studies by orthodontists in different countries 18, 19, 20, 26, 27 . In addition, the PAR index has a good intra-and inter-examiner reliability, with intraclass correlation coefficients of 0.95 and 0.91, respectively 23 . This is in line with the intra-examiner reliability result found as well in the present study. The shortcomings of PAR index are that is fails to adequately record incisor torque, posterior alignment, and changes in the arch dimensions 43 . Furthermore, minor deviations from normal i.e., initial scores of less than 22 points cannot be greatly improved because the case is not severe enough pre-treatment 21 . Moreover, the PAR index uses a weighting system for several subcomponents of the index for example overjet that has a weighting of 6 which results in a high pre-treatment PAR score in cases with large overjet. For that reason, cases with high initial PAR scores are easier to realize remarkable changes in the PAR scores 44 . In contrast to PAR index, the OGS assesses more precisely minor discrepancies in tooth position in all three planes i.e., first, second and third order. The limitation of the OGS is that it only examines the final outcome and without considering the severity of the malocclusion of the difficulty of treatment 45 . Changes in facial profile or cephalometric parameters that reflects the skeletal component of the malocclusion are also not considered in the quantitative evaluation of both indices 23,24,30,44,46 . Patient cooperation which has a great impact on the treatment outcome, is also not considered. Furthermore, both indices are dental professional judgements and may not coincident with patient values. Further studies are needed to clarify the effects of pandemic in orthodontic treatment outcomes based on patient satisfaction. Moreover, since orthodontic practice and patient management must adapt to changes, more attention should be given to tele-orthodontics as it is a tool that seems to have come to stay. The results from the present study cannot be generalized since the intensity of Covid-19 waves differed around the world and clinical activities were suspended differently in different countries. In the present study, half of the treatment time occurred outside the Covid-19 pandemic period, therefore, the pandemic influence on the whole treatment outcome and treatment time could not be assessed. In addition, due to the retrospective study design, selection bias may be introduced as only subjects with complete records were included. Furthermore, only labial fixed orthodontic treatment cases were evaluated. Clear aligner cases, lingual orthodontics appliances and orthognathic surgery patients were not evaluated. • The pandemic group had lower score for marginal ridge height and a higher score for buccolingual inclination. • Final total weighted PAR scores and the total OGS score did not differ between patients that removed their fixed appliance during or before the pandemic. • Patients in the pandemic group had significantly more cancelled appointments and fewer total numbers of booked appointments, but the treatment duration did not differ between the groups. 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