A comparison of orthodontic treatment outcomes using the Objective Grading System (OGS) and the Peer Assessment Rating (PAR) index

Orfan Chalabi,Charles Brian Preston,Sawsan Tabbaa,Thikriat S Al-Jewair

doi:10.21307/aoj-2020-150

Orfan Chalabi, Charles Brian Preston + Show 2 more

Open Access

https://doi.org/10.21307/aoj-2020-150

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Abstract

Abstract Introduction The use of objective criteria is essential to uniformly quantify and measure the severity of malocclusions and the efficacy of different treatment modalities. The Peer Assessment Rating (PAR) index and, more recently, the American Board of Orthodontics Objective Grading System (OGS) were developed to fulfill this need. Aim The aim of this retrospective study was to assess and compare treatment outcomes using the UK and US weighted PAR and the OGS. Materials and methods The sample consisted of randomly selected records of 50 patients treated by residents in one postgraduate orthodontic clinic. UK and US weightings for the PAR index were applied and compared with OGS. Results There was no statistically significant association between the OGS and the PAR index grading systems. Neither the UK nor the US PAR weightings showed statistically significant correlation with the OGS. All cases were ‘greatly improved’ or ‘improved’ according to the PAR index, while most cases (62%) failed according to OGS. There was a statistically significant correlation between the unweighted PAR index and the OGS (r = −0.32, p = 0.024). The US and the UK weightings for the PAR were highly correlated (r = 0.90, p < 0.001). Both weighting systems were also highly correlated with the unweighted PAR (p < 0.001). There were no gender differences found in any of the scoring systems. Conclusions The current PAR index cannot replace the OGS for evaluating treatment outcomes. The current OGS cannot detect the improvement achieved in a treated case.

Highlights

The use of objective criteria is essential to uniformly quantify and measure the severity of malocclusions and the efficacy of different treatment modalities
The American Board of Orthodontics (ABO) has published the Objective Grading System (OGS) to evaluate treatment outcomes using post-treatment dental casts and panoramic radiographs.[3]
The results showed the mean percentage improvement was 84.62% ± 11.16% and 81.05% ± 14.18% for the Peer Assessment Rating (PAR) UK

Summary

Introduction

The use of objective criteria is essential to uniformly quantify and measure the severity of malocclusions and the efficacy of different treatment modalities. Orthodontic treatment results are most often subjectively graded but may be assessed by objective methods, either in clinical settings, study groups, national or state board examinations.[1] Several indices have been used to impartially evaluate a malocclusion and treatment outcome.[1,2]. The American Board of Orthodontics (ABO) has published the Objective Grading System (OGS) to evaluate treatment outcomes using post-treatment dental casts and panoramic radiographs.[3] The OGS. Another popular assessment tool is the Peer Assessment Rating (PAR) index,[4] which measures occlusal traits and allocates scores for tooth alignment, dental impaction, relationships of the buccal segments, overjet, overbite and midline discrepancies. The mean percent reduction in the PAR scores ranged from 68% to 78% in several studies.[7,8,9]

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