正颌外科术后髁状突移位的三维CT研究

目的 探讨正颌手术后髁状突在三维方向上位置变化的规律。方法 应用3-DCT观查了正颌手术矫正的患者10例。结果 CT片上横断面双侧髁突角的变化统计学分析有显著性差异，而冠状面值变化无差异。多元逐步回归检验结果只有横断面左侧髁状突的角度变化可构成方程，入方程的变量为左右移动幅度。结论 在冠状面上髁状突内外无明显移位，而横断面上髁状突长轴发生了旋转。髁状突移位与左右移动幅度显著相关，与原下颌骨形态、下颌骨前后及上下移动幅度无关。

A study on the condylar displacement following orthognathic surgery b y 3-D CT

Objective To analysis condylar position change following orthognathic surgery on the 3-D planes.Methods 10 cases with severe dentofacial deformities corrected by bimaxillary surgery,bilateral ramus split osteotomy (BSSRO) rigid internal fixation with monocortical miniplate were evaluated of the condylar position changes one-week after operations by 3-D CT.Results The changes of bilateral condylar angles on the axial plane of 3-D CT were significant but not significant on the coronal plane.Multiple stepwise regression test showed that left condylar angle change on axial plane was related to the transeverse mandibular movement magnitude.Conclusion On coronal plane condyles are not found to have any lateral movements.But on axial plane condyles rotate a lot,their internal extremities displaced to anterior and external extremities to posterior.The transverse movement of the mandible is a contributing factor to the condylar displacement.However,it is not found that any relationship between condylar position changes and the preoperative mandibular form,mandibular movement magnitude on the sagittal plane existed.