Striving for Perfection: How Stable Is Orthodontic Treatment When Excellent Outcomes Are Achieved? A 9-Year Post-Treatment Retrospective Study.

(1) Aims: The main objective of this retrospective study was to assess the long-term stability of difficult orthodontic treatments treated to an excellent result and to correlate stability to possible prognostic factors. Secondary objectives were to observe the changes in retention protocol over time and to assess Oral Health-related Quality of Life (OHRQoL) after a long-term post-treatment follow-up. (2) Methods: Cases presented for final examination by orthodontic postgraduate students were retrospectively screened for eligibility. Eligible patients were recalled for a post-treatment recall appointment (T2), consisting of a clinical examination and intraoral scan, and were asked to complete the Oral Health Impact Profile-14 (OHIP-14-DK). Gender, age at treatment commencement (T0), treatment modality and duration, and retention protocol were extracted from the records. At T2, the duration of the retention period was recorded, and retainers in place were clinically compared to the original retention protocol. The following variables were assessed on the sets of models at T0, T1 (end of treatment), and T2: arch length and width, overjet and overbite, Dental Aesthetic Index (DAI), Peer Assessment Rating score (PAR), and Little's Irregularity Index (LII). Multiple regression models were conducted. (3) Results: Eighty-five subjects attended T2. The mean post-treatment follow-up was 9.4 years +/- 2.4. In the upper arch, at T1, 74 patients had a combination of fixed and removable retainers, while at T2, 55 had a fixed retainer only. In the lower arch, at T1, 67 patients had a fixed retainer only, with this number increasing to 76 at T2. From T0 to T1, the PAR score improved by 96.1%, with the improvement remaining at 77.5% at T2. The stability of lower inter-canine and upper inter-premolar widths was significantly correlated with the extent of changes during treatment. The presence of a lower fixed retainer at T2 and a low LII at T1 were prognostic factors for stability. The mean weighted total OHIP-14 score at T2 was very low (1.6 ± 2.4 points). (4) Conclusions: In a sample with an initial high-severity malocclusion and treated to an excellent outcome, long-term stability was very good. Good stability can be retained when a lower fixed retainer is present at T2 and when a low LII is achieved at T1.

Assessment of the outcomes and stability after mandibular incisor extraction in orthodontic patients: A systematic review and meta-analysis.

Background: This study assessed the stability of the outcomes after mandibular incisor extraction (MIE) using intercanine width and peer assessment rating (PAR) scores in orthodontic patients. Methods: PubMed, Cochrane Library, Science Direct, Google Scholar, Ovid, and SciELO were systematically searched without restrictions until August 2022. A risk of bias assessment was performed using Newcastle-Ottawa Scale (NOS). The Grading of Recommendations, Assessment, Development, and Evaluation tool was used to assess the quality of evidence. Random effects meta-analysis was performed using RevMan software. Results: Seven retrospective studies met the inclusion criteria and were included. Meta-analysis identified a statistically significant reduction in intercanine width with MIE after the retention period. The mean difference in post-retention changes concerning intercanine width (MD=0.14, 95% CI: -2.17-1.89; P<0.00001) was significantly higher in premolar extraction (PE) compared to incisor extraction and significantly less in non-extraction compared to incisor extraction (MD=0.72, 95% CI: -0.59-2.03; P<0.00001). Improvements in PAR scores from the start of treatment to the retention period indicated a high outcome standard (>70%) with MIE treatment, with no significant difference in the reduction percentage compared to premolar and non-extraction groups. Conclusion: With the existing retrospective studies of limited evidence, treatment outcomes with MIE were found to show good improvements in PAR scores. Some reduction in the intercanine width was evident after the retention period, which was observed even with the other two treatment modalities that were compared. Hence, with careful evaluation, MIE could be considered a valid treatment option.

Clinical Study on the Occlusal Change of Skeletal Class Ⅰ Malocclusion Treated with Invisible Appliance and Fixed Appliance / 昆明医科大学学报

Objective To compare the clinical efficacy of invisible appliance and fixed appliance in the treatment of skeletal class I malocclusion.Methods A prospective cohort study with a minimum sample size of no less than 19 subjects in each group was used,and 46 adult patients with bone type I were eventually enrolled.According to the type of appliance,they were divided into the invisible appliance group(group A)with 25 patients and the fixed appliance group(group B)with 21 patients.Data were analyzed before orthodontic treatment(T0)after(T1)between invisible and traditional fixed orthodontics.Results The static occlusion index and PAR score were improved after treatment,and the differences were statistically significant(P<0.01).The occlusal dynamic parameters including OT,OFAT,OFPT,AOF and DT were significantly improved after treatment(P<0.01).There were significant differences in AOF,forward and lateral DT between the two groups(P<0.01),the invisible group was better than the fixed group.Conclusion Both the dynamic and static occlusal changes can be greatly improved with invisible and fixed appliance in the treatment of patients with class I malocclusion.Invisible appliance is better than fixed appliance in balancing occlusion,eliminating and reducing occlusal interference.

Does quality of orthodontic treatment outcome influence post-treatment stability? A retrospective study investigating short-term stability 2 years after orthodontic treatment with fixed appliances and in the presence of fixed retainers.

OBJECTIVE: The present study aimed to evaluate stability 2 years after orthodontic treatment and to investigate the influence of various pre-treatment and post-treatment prognostic factors on stability. SETTING AND SAMPLE POPULATION: Consecutive patients treated with full fixed appliance and retained with fixed retainers were retrospectively assessed for eligibility. MATERIALS AND METHODS: Digital models were analysed at treatment start (T0), end of treatment (T1) and 2 years post-treatment (T2). The Peer Assessment Rating (PAR) index, Little's Irregularity Index (LII), arch width and length, overjet, overbite and presence of unexpected post-treatment changes were assessed. Multiple regression analyses were conducted to model the relationship of all outcomes with several prognostics simultaneously. RESULTS: The sample consisted of 287 subjects (mean treatment time: 25.1 months, standard deviation [SD] 7.5; mean post-treatment follow-up: 27.5 months, SD 6.1) with a mean weighted PAR score of 29.5 (SD 8.6) at T0, 1.8 (SD 2.9) at T1 and 3.2 (SD 3.6) at T2. At T1, 95% of the subjects had a perfect LII versus 86% at T2. An increased LII at T1 correlated with increased LII and PAR changes from T1 to T2. PAR at T1 as well as overjet at T0 was a significant prognostic factor for PAR at T2. At T2, five cases (1.7%) showed unexpected post-treatment changes related to fixed retainers. CONCLUSION: Short-term post-treatment stability with fixed retainers was very good. Prognostic factors for stability included LII and PAR at T1, suggesting that high-quality treatment outcome in the presence of fixed retainers may ensure post-treatment stability.

Validity and Reproducibility of the Peer Assessment Rating Index Scored on Digital Models Using a Software Compared with Traditional Manual Scoring.

The aim of this study was to assess the validity and reproducibility of digital scoring of the Peer Assessment Rating (PAR) index and its components using a software, compared with conventional manual scoring on printed model equivalents. The PAR index was scored on 15 cases at pre- and post-treatment stages by two operators using two methods: first, digitally, on direct digital models using Ortho Analyzer software; and second, manually, on printed model equivalents using a digital caliper. All measurements were repeated at a one-week interval. Paired sample t-tests were used to compare PAR scores and its components between both methods and raters. Intra-class correlation coefficients (ICC) were used to compute intra- and inter-rater reproducibility. The error of the method was calculated. The agreement between both methods was analyzed using Bland-Altman plots. There were no significant differences in the mean PAR scores between both methods and both raters. ICC for intra- and inter-rater reproducibility was excellent (≥0.95). All error-of-the-method values were smaller than the associated minimum standard deviation. Bland-Altman plots confirmed the validity of the measurements. PAR scoring on digital models showed excellent validity and reproducibility compared with manual scoring on printed model equivalents by means of a digital caliper.

Class II Division 1 malocclusion treatment with extraction of maxillary first molars: Evaluation of treatment and post-treatment changes by the PAR Index.

OBJECTIVE: To investigate occlusal result and post-treatment changes after orthodontic extraction of maxillary first permanent molars in patients with a Class II division 1 malocclusion. SETTING AND SAMPLE: Retrospective longitudinal study in a private practice, with outcome evaluation by an independent academic hospital. Ninety-six patients (53 males, 43 females) consecutively treated by one orthodontist with maxillary first permanent molar extraction were studied, divided into three facial types, based on pre-treatment cephalometric values: hypodivergent (n = 18), normodivergent (n = 21) and hyperdivergent (n = 57). METHODS: Occlusal outcome was scored on dental casts at T1 (pre-treatment), T2 (post-treatment) and T3 (mean follow-up 2.5 ± 0.9 years) using the weighted Peer Assessment Rating (PAR) Index. The paired sample t test and one-way ANOVA followed by Tukey's post hoc test were used for statistical analysis. RESULTS: PAR was reduced by 95.7% and 89.9% at T2 and T3, respectively, compared with the start of treatment. The largest post-treatment changes were found for overjet and buccal occlusion. Linear regression analysis did not reveal a clear effect (R-Square 0.074) of age, sex, PAR score at T1, incremental PAR score T2-T1, overjet and overbite at T1, and facial type on the changes after treatment (incremental PAR score T3-T2). CONCLUSIONS: The occlusal outcome achieved after Class II division 1 treatment with maxillary first permanent molar extractions was maintained to a large extent over a mean post-treatment follow-up of 2.5 years. Limited changes after treatment were found, for which no risk factors could be discerned.

Peer Assessment Rating (PAR) Index as an Alternative for Orthodontic Treatment Need Decision in Relation to Angle Classification.

OBJECTIVE: This study aimed to determine cut-off points for the Peer Assessment Rating (PAR) index in relation with Angle classification to use as an alternative index for the treatment need assessment. METHODS: This study included 607 orthodontic patients aged between 9 and 18 years. Angle classification, PAR, and dental aesthetic index (DAI) scores were determined. The DAI was used as the gold standard to evaluate the subjects for treatment need. The receiver operating characteristics (ROC) analysis was used to evaluate the PAR index in relation to treatment need assessed by DAI. RESULTS: The mean PAR scores for Class I, II, and III malocclusions and total sample were 17.54, 14.27, 18.7, and 20.04, respectively. The areas under the ROC of PAR scores in relation to the DAI assessment were found as 68.3% for the total sample, 66.6% Class I, 59.2% Class II, and 71.3% Class III malocclusions. For the total sample, the optimum cut-off PAR score was 14 in relation to DAI assessment. The cut-off scores for Class I, II, and III malocclusions were 13, 11, and 16, respectively, but considering psychosocial aspects, the recommended score is 14 for Class III. CONCLUSION: The PAR index can be considered to have an acceptable level of validity for the assessment of orthodontic treatment need regarding Angle classification.

Relationships of maxillofacial morphology and malocclusion with handgrip strength in adult women.

OBJECTIVES: Maxillofacial morphology and malocclusion are related to maximum occlusal force (MOF). Although it has been reported that MOF was related to handgrip strength (HS), the relationships between maxillofacial morphology/malocclusion and HS remain unclear. This study aimed to examine the relationships between maxillofacial morphology, malocclusion and HS. SETTING AND SAMPLE POPULATION: Eighty-five women with malocclusion, aged 18-40 years, were selected. MATERIALS AND METHODS: Lateral cephalometric radiographs (SNA, SNB, ANB, mandibular plane-FH, and gonial angles, overjet and overbite), the Peer Assessment Rating (PAR) index and HS were measured. Subjects were classified by the Japanese normal mean value of cephalometric analysis or the reference value which was defined by degree of malocclusion in each PAR index measurement item (small/low: value < mean/reference value, large/high: value ≧ mean/reference value). Measurements were then compared between groups. RESULTS: HS of the large-gonial angle group was lower than that of the small-gonial angle group. In the small-overbite group or high-transverse (PAR index score showing crossbite/scissor bite in the canine and molars) group, HS in the large-gonial angle group was significantly lower than that in the small-gonial angle group. CONCLUSIONS: Our results suggest that gonial angle is the largest factor affecting HS. HS may be especially low in those subjects with a large gonial angle and a small overbite or a crossbite/scissor bite in the molar section.

Comparison of early treatment outcomes rendered in three different types of malocclusions.

OBJECTIVE: To evaluate the outcome of early treatment in Class I, II, and III malocclusions based on the reduction of weighted Peer Assessment Rating (PAR) scores. MATERIALS AND METHODS: Two hundred thirty subjects (female = 105; male = 125) selected from 400 cases were divided into three groups based on their malocclusions (Class I, II, and III). The PAR index was evaluated prior to early treatment (T0), at the end of phase I (T1), and after completion of phase II therapy (T2). The reliability of overall PAR scores was assessed by Bland-Altman plot and intraclass correlation coefficient. The starting age, total weighted PAR scores and their changes after phase I and II treatments, treatment time, and the percentage of correction in the three different malocclusions were assessed by repeated-measures analysis of variance with post hoc analysis. The level of significance was set at P < .05. RESULTS: More than 30% reduction of the weighted PAR scores and less than 10 points of the remaining weighted PAR scores were observed in all malocclusion groups at T1. The Class III group had the highest percentage of correction during phase I treatment. CONCLUSIONS: Early treatment effectively reduced the complexity of Class I, II, and III malocclusions and accounted for 57%, 64%, and 76% of the total correction, respectively, after phase I treatment, as indicated by an overall reduction in weighted PAR scores. The Class III group responded most favorably to early treatment followed by the Class II group.

Stability of anterior tooth alignment 10 years out of retention.

OBJECTIVE: Long-term posttreatment stability of anterior tooth alignment is of major interest to both patients and orthodontists. In the present study we examined the long-term outcome 10 years postretention and investigated the possible influence of treatment-related factors on posttreatment stability of maxillary and mandibular anterior tooth alignment. METHODS: The sample comprised 51 patients treated with full fixed appliances in a university clinic. Average retention time was 1.8 years. All patients received a Hawley appliance in the maxilla and a bonded canine-to-canine retainer in the mandible. The Peer Assessment Rating (PAR) Index, Little's Irregularity Index (LII) and dental cast variables were recorded at pretreatment, posttreatment and 10 years out of retention. Stability of occlusion was assessed with the PAR score percentage improvement method. For each jaw a multivariate regression analysis was performed to identify the influence of treatment-related factors on postretention tooth alignment. RESULTS: The PAR Index percentage improvement decreased from 73.1% posttreatment to 53.5% 10 years out of retention. For both jaws posttreatment increase in anterior irregularity was significantly correlated with the degree of treatment correction. The strongest association was found in the maxilla. Premolar extractions were associated with increased stability of mandibular alignment. CONCLUSIONS: The need for retention appears to increase with the degree of alignment correction, particularly in the maxilla. Extraction of premolars significantly improved long-term stability of mandibular incisor alignment.

Evaluation of orthodontic treatment in patients with extraction of mandible first molar using PAR index and cephalometrics / 口腔疾病防治

Objective@#To access the clinical effect of orthodontic treatment in patients with extraction of mandible first molar. @*Methods @#Nineteen patients (three male and sixteen female) with extraction of mandible first molar because of caries, periapical disease were collected as experimental group. The age was 21.37 ± 5.07. Nineteen patients (seven male and twelve female) with extraction of four premolar as control group, The age was 20.42 ± 4.23. All the patients were treated with orthodontic space closure using MBT preadjusted appliance and sliding mechanics PAR index and cephalomertics that were compared before and after orthodontic treatment. @*Results @#The two groups’ reduction in weighted PAR score and each of the PAR score differences were statistically significant (P<0.01). There was no significant difference between the two groups after treatment in PAR. There were significant changes in U1-NA (°)、U1-NA(mm)、U1-SN(°), but not in the rest of the value in experimental group (P<0.01). The L1-NB(°)、 L1-NB (mm) was significant difference before and after treatment. Extraction spaces of mandible first molars were closed (P<0.01); Good occlusal relationships and soft tissue profiles were achieved in all cases. @* Conclusion @#If the mandibular first molars have serious caries or periapical lesions, removal of mandibular first molar, making full use of the mandibular third molar and keeping health premolars for orthodontic treatment could receive satisfactory results.

Another way of looking at treatment stability.

OBJECTIVE: To determine the contribution of normal physiological changes to the overall manifestation of a relapse after orthodontic treatment. We analyzed long-term changes in the dentition of patients with Class I malocclusions after orthodontic treatment compared with a representative group with untreated Class I malocclusions. MATERIALS AND METHODS: Study participants (n  =  66; mean age, 12 years at treatment initiation) were treated for Class I malocclusions. Dental changes were evaluated at 2, 5, 10, and 15 years after treatment. Control participants (n  =  79) had untreated Class I malocclusions (n  =  53 evaluated at ages 12 and 22 years; n  =  26 evaluated at ages 19 and 39 years). Dental changes were evaluated with the Peer Assessment Rating (PAR) index. RESULTS: In untreated and treated groups, PAR scores increased over time with gender-specific changes. In the untreated groups, the PAR score significantly increased in male participants between the ages of 12 and 22 years (P  =  .04) and in female participants between the ages of 19 and 39 years (P  =  .001). In the treated group, early posttreatment changes were primarily related to the initial treatment response. Later changes in the PAR score could be attributed to physiological changes, with the same gender-specific changes as those observed in the untreated group. CONCLUSIONS: The pattern of physiological changes in dentition for participants between the ages of 12 and 39 was different between sexes. Females showed more relapse than males between 10 and 15 years posttreatment. This distinction should be considered when evaluating long-term orthodontic treatment responses.

Anterior tooth alignment: A comparison of orthodontic retention regimens 5 years posttreatment.

OBJECTIVE: To assess orthodontic treatment outcome at debonding and at 3 and 5 years after orthodontic treatment and to investigate the influence of different retention protocols on anterior tooth alignment. MATERIALS AND METHODS: Using the Peer Assessment Rating (PAR) Index, 169 patients (74 boys, 95 girls) were analyzed at four stages: pretreatment (T0), posttreatment (T1), 3 years posttreatment (T3), and 5 years posttreatment (T5). The PAR anterior component scores (ACSs) were compared between groups with different retention protocols. In the maxilla, protocols were removable retainer until T3 (MAX1), removable and fixed retainer until T3 (MAX2), and removable retainer until T3 and fixed retainer until T5 (MAX3). In the mandible, protocols were no retainer (MAND1), fixed 3-3 retainer until T3 (MAND2), and fixed 3-3 retainer until T5 (MAND3). RESULTS: Mean weighted improvement in PAR score was 88.3% at T1, 86.4% at T3, and 82.1% at T5. The ACS for the maxilla showed no significant differences between the retention protocols at any time point. In the mandible, the group without retention showed a gradual but not significant deterioration in ACS throughout the posttreatment period. At T5 there was a significant difference in ACS between the group that had the retainer removed at T3 and the group that kept the retainer. CONCLUSION: The 5-year treatment outcome, as measured by the PAR Index, was good. Stability of the maxillary anterior alignment 5 years posttreatment did not appear to be influenced by choice of retention protocol. Mandibular anterior alignment was significantly better for the group using a fixed retainer compared with the group where the retainer was removed 3 years posttreatment.

The PAR index for evaluation of treatment outcomes in orthodontics: a clinical audit of 50 cases.

In the context of this study, a clinical audit of cases treated by a single orthodontist was carried out to illustrate one practical application of the PAR index. Fifty pairs of dental casts taken from the patient group before and at the end of orthodontic treatment were evaluated by an orthodontist trained in the use of the PAR index. This evaluation shows that the average overall PAR score for the subjects included in the study fell from an initial value of 25.64 ± 11.73 points to 1.78 ± 2.79 points at the end of orthodontic treatment. The average reduction attributable to orthodontic treatment was 23.86 ± 0.95 points, for an average percentage reduction of 93.36 ± 9.02%. When cases were classified according to the degree of improvement suggested by the nomogram of the PAR index, 23 (46%) were in the "Improved" category after treatment, and 27 cases (54%) in the "Greatly improved" category. This adds up to a total of 100% in these two categories, with none in the "No better" or "Worse" categories. It should be recalled that a high standard of orthodontic treatment is considered to be reached when the average percentage reduction of the PAR score exceeds 70% and when the number of cases in the "Worse or no better" category is below 5%.

Evaluación de la confiabilidad del índice PAR en modelos de estudio físicos y digitales / Reliability assessment of PAR index plaster and digital study models

Introducción y objetivo: El índice PAR evalúa los resultados del tratamiento de ortodoncia en términos de mejora y la calidad técnica de la atención. Se puede utilizar para evaluar las normas de tratamiento de ortodoncia. Una buena oclusión tiene un récord nominal de menos de 5 puntos PAR. El objetivo de este estudio es evaluar la confiabilidad del índice PAR medido en los modelos dentales digitales y físicos para el diagnóstico de problemas oclusales. Materiales y métodos: Este estudio se realizó en 21 modelos de estudio correspondientes a individuos distribuidos equitativamente tanto del sexo femenino como masculino, con diferentes rangos de edades entre 6 y 17 años y en tres tipos de maloclusión (clase I, clase II y oclusiones ideales) escogidos al azar entre 480 modelos disponibles en el grupo de investigación del GIB. Para la medición digital a los modelos de estudio se les tomo un registro de mordida con cera para modelar; las mediciones manuales se realizaron con un calibrador digital y la regla correspondiente al índice PAR; se calibraron 2 investigadores en forma ciega en dos momentos diferentes para la realización de las mediciones. Resultados: Se encontró una excelente confiabilidad de las medidas del índice PAR entre los modelos físicos y los digitales con un coeficiente de correlación intra clase (CCI=0,99) y un intervalo de confianza de 95%. (0,98; 0,99) Conclusión: La medición del índice PAR es igualmente confiable cundo se mide en modelos de yeso que en modelos digitales.

Introduction and objective: The PAR index evaluates the results of orthodontic treatment in terms of improving the technical quality of care. It can be used to assess orthodontic treatment standards. A good occlusion has a nominal record of less than 5 PAR points. The aim of this study was to assess the reliability of the PAR index measured in physical and digital dental models for diagnosing occlusal problems. Materials and methods: This study was conducted in 21 study models of both female and male patients, with different age ranges between 6 and 17 years and three types of malocclusion (Class I, Class II and ideal occlusions) randomly selected from 480 models available in the IPF Research Group. In order to make digital measurements of study models bite registration with modeling wax were taken; manual measurements were made with a digital caliper and ruler for the PAR index; two researchers were blindly standardized at two different times in order to perform the measurements. Results: An excellent reliability of PAR index measurements was observed between physical and digital models with intraclass correlation coefficient (ICC = 0,99) and a confidence interval of 95%. (0,98; 0,99). Conclusions: PAR Index measurements are equally reliable when measured on plaster or digital models.

Evaluation of mandibular incisor extraction treatment outcome in patients with bolton discrepancy using peer assessment rating index.

OBJECTIVE: Mandibular incisor extraction in carefully selected cases as an alternative option to four bicuspid extraction or non extraction treatment has been advocated. The purpose of this study was to determine the degree of improvement in occlusion in patients with Bolton discrepancy treated by one lower incisor extraction using Peer Assessment Rating Index (PAR indexes). MATERIALS AND METHODS: Pre and post treatment dental casts of 14 patients treated with one lower incisor extraction were included in the study. Pre and post treatment dental casts were scored with PAR index. 70% reduction in PAR index was considered as high standard improvement. To test the hypothesis that the mean improvement in dental occlusion after one mandibular incisor extraction is at least 70%, one-tail one-sample student t-test was used. RESULTS: The mean improvement in dental occlusion in this group of patients was 78%. Fifty percent of the cases finished with a post treatment PAR score of 2. Spearman correlation coefficient was 0.763 (p<0.01), showing that more severe cases had greater post treatment PAR scores. CONCLUSION: Mandibular incisor extraction treatment may provide a high standard treatment outcome.

Análise dos resultados do tratamento ortodôntico por meio do índice PAR / Analysis of the results of orthodontic treatment using the PAR index

Introdução: para que se tenha uma avaliação fidedigna dos resultados finalizados ortodonticamente, é necessário que seja aplicado um índice oclusal para que determinadas falhas possam ser diagnosticadas. O índice PAR foi desenvolvido com o intuito de avaliar objetivamente alterações oclusais que podem ocorrer após o tratamento ortodôntico como também comparar as melhoras conseguidas. Objetivo: diante dessa necessidade, resolveu-se avaliar quantitativamente, através do índice PAR, os resultados dos tratamentos ortodônticos finalizados e quais parâmetros oclusais mais influenciaram nesses resultados finais. Material e Métodos: foram analisados os modelos pré e pós-tratamento de 58 pacientes, obtendo decada um o índice PAR inicial (TI) e final (T2). A idade média dos pacientes foi de 13,82 anos e com tempo de tratamento médio de 3,3 anos. Resultados: através da análise estatística descritiva, observou-se um índice PAR inicial médio de 19,22, sendo reduzido a um índice PAR final de 3,97, tendo uma redução de 79,13% com o tratamento ortodôntico. Houve uma correlação significativa (p < 0,001) entre os índices PAR inicial e final como também entre o PAR inicial e a correção deste índice durante o tratamento. O componente oclusão posterior foi o que mais influenciou no valor do índice PAR inicial e final. Conclusão: pode-se concluir que houve bom padrão de finalização, ou seja, os casos finalizados tiveram resultados clinicamente aceitáveis.

Introduction: to have a reliable evaluation of the results of completed orthodontic treatment is required to be applied to an occlusal index that certain faults can be diagnosed. The PAR index was developed with the aim of objectively evaluating occlusal changes that may occur after treatment but also to compare the improvements achieved. Purpose: given this need, we decided to assess quantitatively, through the PAR index, the results of completed orthodontic treatment and occlusal parameters wich most infl uence these outcomes. Material and Methods: it was analysed the models pre- and post-treatment of 58 patients, giving each of the initial PAR index (T1) and fi nal (T2). The average age of patient was 13.82 years and mean treatment tima of 3.3 years. Results: through statistical analysis, we observed an average initial PAR score of 19.22 was reduced to a fi nal PAR index of 3.97, with a reduction of 79.13% with orthodontic treatment. There was a significant correlation (p < 0.001) between the initial and fi nal PAR index, but also between the initial PAR and correction of this index during treatment. The component “posterior occlusion” was the strongest influence on the value of initial and final PAR index. Conclusion: it can be concluded that there was a good ending pattern, ie, the cases were finished clinically acceptable results.

Quantitative evaluation and affecting factors of post-treatment relapse tendency / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to quantitatively evaluate relapse tendency after orthodontic treatment and determine the contributing factors by using the American Board of Orthodontics objective grading system (ABO-OGS). METHODS: The subjects were 80 patients with more than 2 years of retention period after completing orthodontic treatment at the dental hospitals of Busan University, Kyunghee University, and Dankook University. The posttreatment (T2) and post-retention (T3) ABO-OGS measurements were analyzed in relation to age, gender, Angle's classification, extraction, retention period, and pretreatment condition (initial peer assessment rating (PAR) index, T1) by multiple regression analysis. RESULTS: Among the 7 ABO-OGS criteria, alignment worsened but occlusal contact and interproximal contact improved in T3, but not in T2 (p < 0.01). The 4 other criteria showed no significant differences. Multiple regression analysis showed that alignment, occlusal relationship, overjet, and interproximal contact were significant linear models, but with a low explanation power. Age, gender, Angle's classification, extraction, retention period, and pretreatment condition (initial PAR index, T1) had little influence on the ABO-OGS changes between T3 and T2. CONCLUSIONS: An orthodontist's understanding of post-treatment relapse tendency can be useful in diagnosis and during patient consultation.

The objective and quantitative analysis of malocclusion: Part 1. Objective malocclusion severity and subjective treatment difficulty / 대한치과교정학회지

The evaluation of malocclusion has to be done quantitatively and qualitatively. This will be lead toward an analysis of malocclusion severity as well as treatment difficulty. The method of proper evaluation of malocclusion severity and treatment difficulty is necessary to assess treatment effect and efficiency for the orthodontists and to establish fundamentals for planning and executing the health-related policies in private and public institutions. The purposes of this study as the first part of the objective and quantitative analysis of malocclusion were 1) to measure treatment difficulty based on the opinions of several orthodontists, and 2) to investigate the relationships between objective malocclusion severity and subjective treatment difficulty. 100 pairs of dental casts that had various types and severity of malocclusion were selected from the orthodontic departments of Kyunghee University and Samsung Medical Center. The objective malocclusion severity was measured with the PAR (Peer Assessment Rating) index and the subjective treatment difficulty was evaluated by 8 experienced orthodontists. The relationships between objective malocclusion severity and subjective treatment difficulty were statistically evaluated. There were significant relationships between objective malocclusion severity and subjective treatment difficulty, especially in the measurements of the upper anterior alignment, the buccal occlusion, the overjet, the overbite and the midline discrepancy in the malocclusion components. The results of this study can provide the background knowledge to develop a new occlusal index, which contains both the malocclusion severity and treatment difficulty for Korean orthodontists.

The objective and quantitative analysis of malocclusion: Part 2. Influence of malocclusion compenents to treatment difficulty / 대한치과교정학회지

As one of the variations in growth and development of the craniofacial complex, malocclusion shows lack of concordance in the recognition and severity of malocclusion for dentists as well as the acceptance and need of orthodontic treatment for the patient. The purposes of this study were 1) to examine the relationships between objective malocclusion severity and subjective treatment difficulty, 2) to evaluate the effect of malocclusion components to the subjective perceived difficulty of treatment, 3) to establish the weighted values of malocclusion components to reflect the treatment difficulty. 100 pairs of dental casts with the general characteristics of malocclusion, were selected from the orthodontic departments of Kyunghee University and Samsung Medical Center. The severity of malocclusion was evaluated by the author with the PAR index. The perceived treatment difficulty and the estimated treatment duration on these dental models were evaluated by 8 experienced orthodontists. The relationships between the objective malocclusion severity and the subjective treatment difficulty were statistically evaluated, and the weighted values of malocclusion components to reflect treatment difficulty were statistically formulated. There were significant relationships between objective malocclusion severity and subjective treatment difficulty. The malocclusion components which significantly affected the treatment difficulty and their weighted values in parentheses were as follows; upper anterior alignment (1), overbite (2), buccal occlusion (3), midline (4), and overjet (5). This study provides the fundamental principle to evaluate the objective malocclusion severity which is reflected by the subjective treatment difficulty of Korean orthodontists.