Does intraoral miniplate fixation have good postoperative stability after sagittal splitting ramus osteotomy? Comparison with intraoral bicortical screw fixation

Purpose Bicortical screw fixation systems and miniplate with monocortical screw fixation systems have been reported mainly in bilateral sagittal split ramus osteotomy (BSSO). This study compared postoperative stability between these 2 fixation systems by an intraoral approach. Materials and Methods This was a retrospective cohort study. The study sample was composed of patients treated by BSSO at the authors' institute from January 2006 through December 2012. All cases had facial symmetry and were performed by setback surgery. The predictor variable was treatment group (intraoral screw fixation [SG] vs intraoral miniplate fixation [MG]), and the primary outcome variable was stability defined as the change in the position of point B. Other outcome variables were stability defined as the change in the position of the menton, blood loss, incidence of postoperative temporomandibular joint disorder, and nerve injury. Descriptive and bivariate statistics were computed and the P value was set at.05. Results Seventy-five patients (35 men and 40 women; mean age, 25.8 yr) were divided into 2 groups (39 SG cases and 36 MG cases). Postoperative changes at point B and the menton in the 2 fixation groups were not statistically different. Lingual nerve injury occurred only in SG cases. Moreover, total blood loss was greater in SG cases. Conclusion An intraoral miniplate with monocortical screw fixation system is recommended over intraoral bicortical screw fixation for bone segments in setback BSSO in patients without facial asymmetry.