Análise de elementos finitos de cinco técnicas de fixação na osteotomia sagital minimamente invasiva

Abstract

There are many studies about fixation techniques in conventional bilateral sagittal split osteotomy, but little is known about these in anterior oblique sagittal split osteotomy frequently applied in the minimally invasive approach. The present research aims to compare five fixation techniques in anterior oblique sagittal split osteotomy, using finite element analysis. In this in silico study on a hemimandible, an 8 mm linear advancement was performed, and five 2.0 mm system fixation groups were created: three bicortical screws in a straight line (group 1); one straight four-hole miniplate (group 2); one straight four-hole miniplate associated to one bicortical screw (group 3); one straight four-hole miniplate associated to two bicortical screws (group 4) and one straight six-hole orthognathic miniplate (group 5). Then, a 260.68 N vertical load at their first molar was applied. Maximum principal stress at the cortical bone, von Mises stress on each fixation, stress distribution and distal segment dislocation were measured and compared between all groups. Groups 1 and 4 presented similar maximum principal stress and von Mises stress measurements, but dislocation was lower and stress distribution was better in the last. Group 5 performance was the most unfavorable among the sample studied, indicating a higher susceptibility to failure from a clinical perspective.