骨性Ⅲ类错正颌手术前、后面部软、硬组织变化比率的三维研究

目的 研究骨性Ⅲ类错畸形患者面部软、硬组织三维方向上变化的相关性,以及手术前、后软、硬组织的变化比率,以期更好地对术后软组织外貌进行预测。方法 对20例骨性Ⅲ类错畸形成人患者分别于术前2周及术后3个月进行颅面CT扫描和三维重建及面部软组织3D摄影成像,将采集的数据导入Dolphin软件,转换为三维面像数字化模型,建立三维测量坐标系(轴面、矢状面及冠状面),筛选19个软、硬组织标记点并进行测量、对比和配对,共12对。读取标记点的三维坐标（X、Y、Z）,进行手术前、后的定点对比测量,采用 SPSS 22.0 软件包对测量数据进行统计学分析。结果 12对软、硬组织标志点在X轴即左右方向仅Pn/A、Gn'/Gn及Me'/Me存在相关性,在Y轴即上下方向仅Gn'/Gn存在相关性,在Z轴上所有软、硬组织配对点均存在相关性。除UL'/UI及UL/SPr外,均为高度相关。手术前、后,下颌的软、硬组织测量标志点的变化比率大于上颌。结论 骨性Ⅲ类错畸形患者双颌手术前、后软、硬组织的变化主要集中于Z轴即前后向的变化,各软、硬组织配对标志点间呈线性相关关系,且下颌软、硬组织位移比率大于上颌。

Three dimensional study on change ratios of hard and soft tissue after orthognathic surgery

PURPOSE: To investigate the change ratios of soft and hard tissue after orthognathic surgery three-dimensionally in osseous Class Ⅲ patients, in order to predict postoperative soft tissue three-dimensionally. METHODS: Twenty adult patients were selected as the experimental group, craniofacial spiral CT and three-dimensional (3D) stereophotogrammetry were conducted 2 weeks before surgery and 3 months after surgery. Dolphin imaging software was used to establish 3D image digitizing model and 3D measurement coordinate system. Nineteen soft and hard tissue land marks were selected and matched into 12 pairs. 3D coordinate value of these landmarks were read both before and after surgery and were used for statistical analysis with SPSS 22.0 software package. RESULTS: There was a linear relationship only in Pn/A, Gn'/Gn and Me'/Me in X axis, in Gn'/Gn in Y axis and all pairs of landmarks had a close correlation except UL'/UI and UL/SPr in Z axis. Additionally, the change ratio between soft and hard tissue landmarks of mandible was greater than maxilla. CONCLUSIONS: The changes of soft and hard tissue after orthognathic surgery only lie in Z axis(forward and backward), each pair of matched landmarks exhibits a linear relationship, and the change ratio of mandible is greater than the maxilla.