Outcome of Invisalign® Orthodontic Treatment using PAR Index

The Invisalign® system uses a series of clear plastic aligners to straighten teeth. Objectives: The objective of this study was to assess the outcome of orthodontic treatment using the Invisalign® system. Methods: The Peer Assessment Rating (PAR) index was used to assess pre- and post-treatment study models of 55 patients in a clinical trial evaluating different attachments. Subjects with teeth needing rotations, intrusive and extrusive tooth movement not done commercially were treated in this trial. Contact point displacements, buccal occlusion, overjet, overbite, and midlines were scored. Results: Mean PAR score decreased from an initial 19.82±7.24 to final 9.77±5.93 (p<0.0001). Maxillary and mandibular contact point displacements decreased from 4.24±1.99 to 1.6±1.77 (p<0.0001) and 4.53±2.57 to 1±1.55 (p<0.0001) respectively. Initial scores for occlusion(2.89±1.3), overjet(1.53±1.03), overbite(0.89±0.85), and midline(0.07±0.26), decreased to 2.53±1.17(p=0.02), 0.4±0.6(p<0.0001), 0.36±0.59(p<0.0001), and 0.04±0.19(p=0.32) respectively. Conclusion: There is significant improvement in outcomes in patients treated with Invisalign® as measured by the PAR index. This research was supported by UFCD Student Summer Research Fellowship, CollaGenex Pharmaceuticals, Inc., and Align Technology.