Comparison of 2 Invisalign tray generations using the Peer Assessment Rating index

Abstract

This study aimed to establish if there is a significant difference in effectiveness between 2 generations of Invisalign trays in terms of Peer Assessment Rating (PAR) score reduction for finished patients from a graduate orthodontic clinic. Forty-five pretreatment and posttreatment patients treated with the previous Invisalign material and 49 pretreatment and posttreatment patients treated with SmartTrack material were scored using the Peer Assessment Rating (PAR) index. Both groups were controlled for initial weighted PAR score, age, gender, and treatment time. The 2 generations were compared in regard to absolute reduction, percent reduction, and great improvement in PAR score. The mean absolute reduction in weighted PAR score between the groups was not statistically significant (P=0.526). The mean percent reduction in weighted PAR score between the groups was not statistically significant (P=0.210). The proportion of great improvement between the groups was not significant (P=0.526). Only 6 of the 8 components of occlusion had enough variation to be modeled. An absolute reduction in unweighted PAR score was not significantly different between the groups for maxillary anterior alignment, overjet, or mandibular anterior alignment (P=0.996, 1.000, and 0.114, respectively). Percent reduction in unweighted PAR score was not significantly different between the 2 groups for an anteroposterior, overbite, or transverse (P=1.000, 1.000, and 1.000, respectively) relationships. Our study indicates that both generations of Invisalign aligners improved the malocclusion to a similar degree according to the PAR index. Patient-centric benefits of SmartTrack aligner should also be considered by the provider.