The objective of this study is to assess the biomechanical efficacy of different attachment systems in facilitating the lower canine retraction using clear aligners by means of a finite element method (FEM) analysis.

A FEM was developed by utilizing intraoral scan data and CBCT data from an 18-year-old female with ideal occlusion. Four experimental groups were assessed: group 1 (unattached), group 2 (single vertical rectangular attachment), group 3 (double vertical rectangular attachments), and group 4 (optimized quarter-ellipsoid attachments). The study evaluated the stress distribution, plastic deformation and displacement of the crown and root during simulated canine retraction.

Highest bodily translation (85–90%) was observed with optimized attachments (group 4) attaining nearly equal crown and root displacement. Tipping was observed in group 1, less of bodily movement was seen (60–65%) compared to group 2, which demonstrated better physiological translation (70–75%), while group 3 further enhanced efficiency to 75–80%. Group 4 exhibited the most uniform stress distribution, and plastic deformation was minimal (0.01 mm), suggesting superior force application and aligner stability.

The efficiency of canine retraction was considerably improved by optimized quarter-ellipsoid attachments, which resulted in minimal stress concentration and deformation. These findings substantiate the use of optimized attachments to improve the results of clear aligner treatment. Further clinical research is advised to verify these findings and investigate alternative attachment designs and materials to optimize aligner therapy.