A comparative evaluation of the hybrid technique for fixation of the sagittal split ramus osteotomy in mandibular advancement by mechanical, photoelastic, and finite element analysis.

OBJECTIVE This study evaluated the mechanical characteristics and stress distribution of the hybrid technique fixation of the sagittal split ramus osteotomy. STUDY DESIGN In the mechanical test, 10 polyurethane replicas of human hemimandibles of each group were submitted to linear loading test. For the photoelastic evaluation, 3 hemimandible replicas of photoelastic resin were subjected to photoelastic analysis. In the finite element analysis, 3 computer models simulated the displacement and the results of maximum principal stress were analyzed. RESULTS The results of this study demonstrated that the fixation technique with 3 bicortical screws presented better mechanical resistance and stress distribution pattern when compared with the hybrid technique that, on the other hand, presents better results in comparison with a miniplate and monocortical screws. CONCLUSIONS The results suggest that the hybrid technique increased the resistance and improved stress distribution of miniplate/monocortical screw fixation, maintaining most of the advantages of this technique.