Three-Dimensional Evaluation of Clear Aligner Transverse Treatment Outcome.

Objectives: Evaluate the predictability of clear aligner treatment in correcting maxillary transverse relations using Cone Beam Computed Tomography (CBCT).
Methods: This retrospective study included 19 orthodontic patients (6 males and 13 females, mean age 37.6 years). Subjects underwent orthodontic treatment using Invisalign® and their treatment included transverse correction. Predicted transverse tooth movements were obtained from Clincheck®, while actual transverse tooth movements were calculated by measuring the difference between Pre- and Posttreatment tooth position using CBCT. CBCT Measurements were done using Carestream Imaging Software (version 7). Statistical analyses were done using SPSS version 25. Paired sample t-test was used to compare the mean differences between predicted and actual transverse movements at the crown level.
Results: There was a significant difference between the actual and predicted expansion at the first molars, mean difference = -1.8, P<0.0001. No significant differences were found between the actual and predicted expansion measurements at the second premolars and canines, p = 0.22 and 0.76, respectively. There was a significant correlation between actual and predicted expansion at the premolar and canine level (r=0.66 and 0.63, respectively).
Conclusions: Orthodontic clear aligners seem able to achieve transverse corrections. However, transverse movements at the premolar and canine teeth are more predictable than in molar teeth.