Evaluation Of Orthodontic Treatment Outcome In Patients With First Molar Extractions By Means Of PAR Index

ObjectiveTo assess the clinical effect on orthodontic treatment with first molar extractions using the PAR (Peer Assessment Rating) index. The aim of this research is to provide the references for the clinical plan of orthodontic treatment.Methods20 cases treated with first molar extractions were chosen from the Department of Orthodontics of stomatological hospital of China Medical University from 2003 to 2010. There were 6 males and 14 females, aged from 12 to 25 years with an average age of 16.5 years. All of them treated with 1 to 4 first molar extractions. Pre-and post-treatment study models of 20 cases with first molar extractions were assessed by the PAR (Peer Assessment Rating) index.ResultsThe PAR score of 20 cases was 29.56±7.07 before treatment, which was 2.00±2.00 after treatment, and decreased significantly after orthodontic treatment(P＜0.01); The weighted PAR score of 20 cases was 24.25±8.77 before treatment, which was 1.94±2.54 after treatment, and decreased significantly after orthodontic treatment(P＜0.01). The PAR score of the teeth alignment, buccal occlusion, overjet, overbite and centerline condition was significantly different after orthodontic treatment(P＜0.05). The mean reduction of PAR total score was 27.56±6.39, with the mean percentage reduction of (93.63±6.02)%. The mean reduction of the weighted PAR score was 22.31±9.18,with the mean percentage reduction of (90.40±15.53) %.12 cases (60%) with malocclusion were classified as'greatly improved',8 cases (40%) were classified as'improved', and none were'worse or no different'.When treatment finished, all the 20 cases gained satisfactory results, all the teeth lined up in order, normal overjet and overbite were achieved, molar space was completely closed, good occlusal relationship was established.Conclusions1. Assessing the clinical effect quantitively with the PAR (Peer Assessment Rating) index on orthodontic treatment with first molar extractions is relatively objective.2.Orthodontic treatment with first molar extractions could achieve satisfactory curative effect, which was a viable clinical treatment program.