Comparison of the predicted and achieved labiolingual inclinations of the maxillary central incisors in adult Class II division 2 malocclusions treated with clear aligners.

Objective: This study aimed to compare the predicted and achieved labiolingual inclinations of the maxillary central incisors in adult Class II division 2 malocclusions treated with clear aligners using Power Ridges^® and composite attachments.

Methods: This retrospective study included 24 patients (mean age, 26.5 ± 3.3 years). The patients had Class II division 2 malocclusion and were treated with non-extraction with Invisalign^® clear aligners with either Power Ridges^® or composite attachments to enhance the predictability of required change in labiolingual inclination for the maxillary central incisors. Before treatment, treatment prediction and final digital models were exported as stereolithography files and superimposed using the eModel 9.0 "Compare" software. The predicted and achieved labiolingual incisor inclinations were compared.

Results: The mean accuracies of the achieved inclination of the central incisors were 68.3% in the Power Ridges^® group and 71.6% in the attachments group. No statistically significant differences in predictability were found between the groups (P > 0.05). A low positive correlation was observed between the predicted inclination change and the average absolute difference between the predicted and achieved inclinations (r = 0.19).

Conclusions: Predicted labiolingual inclination is not fully achieved with clear aligners in both the Power Ridges^® and attachment groups. Clinicians must take measures to counteract this limitation, specifically in Class II division 2 cases.