Displacement Patterns of the Maxilla During Parallel and Rotational Setback Movements: A Finite Element Analysis

BACKGROUND The purpose of this analysis was to evaluate the displacement patterns of the maxilla under parallel and rotational setbacks using the finite element method (FEM). MATERIAL AND METHODS A three-dimensional (3D) finite element model of a hemimaxilla was constructed. Through a conventional Le Fort I osteotomy, 2 and 3 mm of posterior movement in a parallel and rotational manner were simulated and the displacement pattern of the maxilla in each movement type was evaluated. RESULTS Both parallel and rotational setbacks resulted in lateral and inferior displacement of the maxillary segment. The largest inferior displacement was 3.0 mm and the largest lateral displacement was 1.84 mm. All lateral displacements in the anterior region were found to be more than 1 mm. CONCLUSIONS The results of this study may provide insight into how the maxilla tends to move during total maxillary setback surgery.