Early treatment outcome assessed by the Peer Assessment Rating index

In this study, the Peer Assessment Rating (PAR) index was used to objectively evaluate early treatment outcomes. Pretreatment and posttreatment casts of 103 consecutively treated patients were analyzed. The mean chronological, skeletal, and dental ages were 9. 82, 9.76, and 9.32 years, respectively. Calibrated examiners scored all models using the PAR ruler. PAR scores were weighed by means of a validation exercise. Cronbach alpha reliability analysis was used to establish the consistency of the subjective rating among 10 orthodontists of the severity of malocclusion. Pearson's correlation coefficient was used to assess the association among the orthodontists and the total PAR scores. Multiple regression analysis was used to determined the optimum weight of the PAR scores. Pretreatment and posttreatment differences were evaluated with t tests. The association between PAR scores and classification of malocclusions and treatment categories was assessed by means of multivariate analysis of variance (MANOVA). A reduction in the PAR index was observed for the mean raw and weighted scores, from 15.82 to 8.82 and from 5.28 to 3.73, respectively (P <.001). Twenty percent of the sample greatly improved the PAR index, by a 70% reduction.3 Forty-eight percent improved scores by at least a 30% reduction.4 The remaining 32% did not reduce scores by at least 30%. Subjects with both Class I and Class II malocclusions reduced their scores similarly. There was no statistically significant association between reduction of PAR scores and treatment modalities.