We retrospectively evaluated the results of mandibular setback by sagittal splitting ramus osteotomy performed by our department between 1989 at 2005. Two hundred-one patients were grouped into three categories; nonrigid fixation using intraosseous wiring with a mean intermaxillary fixation (IMF) period of 38.9 days (52 cases), rigid fixation consisting of positioning screw (18 cases, mean IMF period; 21.7 days) and mini-plate (131 cases, mean IMF period; 21.4 days) were reviewed. Regarding functional disturbance after surgery, a higher incidence of neurosensory deficiencies of mental nerve and TMJ disorders were observed in cases in which positioning screw or mini-plate were used, in comparison with wire osteosynthesis cases. To determine skeletal relapse within 12 months after surgery, lateral cephalograms were employed for cases in which the amount of R-, L- set back differences were less than 3mm. The relapse was minimal in positioning screw cases, while the mini-plate fixation showed a greater amount of relapse compared to wire fixation, suggesting that three-dimensional repositioning of temporomandibular joint and longer term intermaxillary fixation were useful to obtain skeletal stability.
下顎枝矢状分割法における骨片固定法の違いによる術後成績の比較検討
