Three-dimensional finite element analysis to evaluate biomechanical effects of different alveolar decortication approaches on rate of canine retraction.

INTRODUCTION: The aim of this study was to compare different corticotomy approaches and determine their biomechanical effects on rate of canine displacement when compared to conventional orthodontics. METHOD: Three-dimensional Finite Element Models with conventional non-corticotomy approach (model 1) and three corticotomy approaches ensuing buccal and palatal vertical cuts (model 2), interseptal bone reduction (model 3), buccal vertical cuts (model 4) were fabricated. Displacement of the canine and von Mises stresses in the canine and trabecular bone were calculated and compared under a distal retraction force of 1.5N. RESULTS: The maximum displacement of canine with minimum anchorage loss was seen in model 3 followed by model 2, model 4 and model 1. The maximum equivalent (von Mises) stress was concentrated mainly on the distal side of canine in model 3 and had a uniform distribution of stresses on entire root surface. CONCLUSIONS: Corticotomy approaches effectively accelerated maxillary canine retraction, exhibiting twice the rate of canine movement with minimum anchorage loss when compared to non-corticotomy approach. Corticotomy with interseptal bone reduction was most effective in terms of canine displacement and stress distribution.