Iterative Finite Element Analysis of Buccolingual Width on Canine Distal Movement in Clear Aligner Treatment

This study investigated the biomechanical effects of varying buccolingual beam widths in maxillary first premolar extraction spaces on canine distal bodily movement during clear aligner treatment. Using finite element analysis, four distinct models were constructed, incorporating beam designs with widths of 0 (edentulous), 1, 2, and 3 mm within the extraction space. Each model underwent a comprehensive 50-stage iterative simulation to evaluate canine displacement patterns, tipping, rotational movements, aligner deformation characteristics, and magnitudes of forces and moments applied to the canines throughout long-term tooth movement. Group 0 (no beam, 0 mm beam width) exhibited the greatest crown displacement and tipping angle. In contrast, Group 2 (2 mm beam width) most effectively reduced the final angulation of the canine, whereas Group 3 (3 mm beam width) was most effective in controlling unwanted rotation and minimizing deformation of the clear aligner. Furthermore, an increase in the beam width was associated with a trend of higher initial force and lower initial moment. Notably, relatively high levels of both force and moment were maintained during the later stages of the simulation, which is advantageous for sustained control of tooth movement. In conclusion, incorporating a beam of 2–3 mm width into the maxillary first premolar extraction space appears to be optimal for managing canine tipping and rotation while promoting bodily movement of the tooth.