A retrospective study of two-stage treatment outcomes assessed with two modified PAR indices

This retrospective study was undertaken to evaluate the long-term outcome of two-stage (functional/fixed) Class II treatment. A modified peer assessment rating (PAR) was applied to the records of 27 patients who had been recalled an average of 9 years after the completion of the second phase of treatment. UK and US weightings were applied. Analysis of variance identified significant differences among treatment stages. The greatest change in PAR score occurred during the first (functional) phase of treatment. By the end of the second phase, there had been an 83% reduction in PAR score. At recall, however, the PAR scores had increased significantly, due largely to relapse in overjet and in the lower labial segment. These results call into question the ultimate utility of early, two-stage treatment regimens. Although the differences between the UK and USA weightings were smaller than anticipated, the nature of the relapse seen here argues against the American exclusion of the lower labial segment.