上颌骨改良Le FortⅠ型截骨术的三维建模和术后咬合有限元分析

Three-dimensional modeling of modified Le FortⅠosteotomy of the maxilla and finite element analysis of postoperative occlusion

目的根据CT扫描数据,基于4种软件建立光顺的上颌骨三维几何模型,模拟改良Le FortⅠ型截骨术及固定方案,对患者术后咬合情况进行有限元分析。方法使用Mimics软件初步处理CT图像,建立STL模型。将模型导入Inspire Studio软件中,建立光滑的PolyNURBS几何模型。使用SpaceClaim软件,模拟手术截骨及钛板、钛钉固定方案。使用ANSYS Workbench软件,对术后患者咬合情况进行三维有限元分析。结果仿真结果显示,在磨牙咬合状态下有限元模型的连接关系建立准确无误。在共计6 N的咬合力作用下,钛板最大等效应力为73 MPa。结论本研究采用的上颌骨建模和分析方法可获得适用于仿真分析的光滑几何模型,有限元分析结果可以为各类正颌手术的固定方案提供参考。

Objective To establish a smooth three-dimensional(3D)geometric model of the maxilla based on CT data using four different software packages,to mimic the modified Le FortⅠosteotomy and its fixation scheme,and to perform a finite element analysis of the postoperative occlusion.Methods CT data were preliminarily processed using Mimics software to produce an STL 3D model.The model was then imported into Inspire Studio software to create a smoothed PolyNURBS geometric model.SpaceClaim software was used to model the surgical osteotomy and fixation schemes.Finally,ANSYS Workbench was used to conduct a 3D finite element analysis simulating the patient’s occlusion after surgery.Results The simulation results showed that the connection relationship of the finite element model was accurately established under the molar occlusion condition.Under a total occlusal force of 6 N,the maximum equivalent stress of the titanium plate was 73 MPa.Conclusion The maxillary modeling and analysis method used in this study can produce a smooth geometric model suitable for finite element simulation.The results of this study can provide reference for various fixation schemes in orthognathic surgery.