面中部牵张成骨有限元研究

Three-dimensional Finite Element Study on Middle Face Advancement with Distraction Osteogenesis

对一骨性 类面型女性的面部软组织进行了计算机三维图形构建 ,并应用有限元法对牵张成骨手术的L e Fort 、 、 型三种手术方案进行三维有限元仿真。预测了术后面部软组织变化 ,确定颜面部特征点变形和截断骨块牵移量的比例 ;分析 L e Fort I型上颌复合体截断骨块前移的阻力中心 ,定位于软组织 A点约 30 mm后的小区域。结果表明 ,三维有限元仿真研究应用于牵张成骨手术中 ,能够很好的为手术实施中前牵引力作用点和方向提供指导 。

Based on the anatomic structure of a girl with calss III skelet al malocclusion, a three dimensional finite element biomechanical model of facial soft tissue was established. With the use of this model, three surgery plans of distraction osteogenesis, LeFort I,II,III maxillary complex advancement in the direction of functional occlusal plane, were simulated. As a result, the facial soft tissue deformation was predicted and the ratio of the facial location deformation to the free bone advancement was calculated. The facial shape after surgery could be viewed in 3D. In addition, the location of center of resistance was investigated when the free bone was protracted forward in the process of LeFort I maxillary complex advancement; it was located at a site about 30mm posterior to the soft tissue A point. The research result indicates that three dimensional finite element research on distraction osteogenesis can provide instruction for setting the suitable protraction point and direction of the protraction force in surgery, and by predicting the facial soft tissue deformation, it also can provide the surgeon and patient with information on the options and reference to the surgery plans.