Biomechanical analysis of mandibular bilateral sagittal split ramus osteotomy with bicortical screws internal fixation / 实用口腔医学杂志

ABSTRACT

Objective: To study the mandibular bilateral sagittal split ramus osteotomy (BSSRO) with bicortical screws rigid internal fixation(RIF) with the three-dimensional finite element method, and supply directions for clinic practice.Methods:CT scanned technology and the finite element software (Ansys) were used to establish the three-dimensional finite element model of BSSRO with bicortical screws RIF. The stress distribution of the mandible and the RIF and the displacement of split mandible were calculated under three kind of occlusion situation.Results:Under the same kind of occlusion situation, the stress and displacement of the split mandible with single upper screws fixation was higher than that with the reverse "L" screws fixation, the stress and displacement of the split mandible with 2.0 mm diameter screws fixation was higher than that with 2.7 mm diameter screws fixation. With the same kind of fixation method, the stress and the displacemen of the mandible under the incisor occlusion was the highest.Conclusion:The fixation distance, position, distribution angle of the bicortical screws all have effects on the fixation stability. The patient should avoid the incisor occlusion after the surgery.