颧骨“L”形截骨降低术的三维有限元模型的建立与分析

目的:建立关于颧骨"L"形截骨降低术的三维有限元模型,探讨该术式在生物力学方面的特点。方法:采集高颧骨畸形患者术前头颅螺旋CT,将数据导入相应医学图像处理软件,对颧骨复合体及手术相关区域进行分体三维重建、手术模拟,应用有限元软件对模型进行网格划分,通过CT扫描灰度值的转换,对各部分材质的弹性模量、泊松比参数进行赋值,再模拟术中对颧骨、颧弓的施力,分析颧骨复合体生物力学情况。结果:建立了颧骨"L"形截骨降低术的三维有限元模型,其几何相似性、力学相似性高。运用三维有限元法生物力学分析,术中按压颧骨复合体,颧弓根部出现一个明显的应力集中,颧骨颧弓产生向内侧的形变。结论:在颧骨"L"形截骨降低术术中按压颧骨复合体,是能够在颧弓根部造成预期的青枝骨折,使颧骨产生内收、降低的形变。

Three dimensional finite elements modeling and analysis of the reduction malarplasty with L-shaped osteotemy

Objective To establish three dimensional finite element model of the Reduction Malarplasty with L-shaped Osteotemy,and to explore biomechanical characteristics of the surgery.Methods By using medical image processing software,three dimensional reconstruction and L-shaped osteotemy simulation were performed based on the CT data of a patient with prominent malar complex.Followed the 3D model remeshing,material properties assignment with gray value conversion,and setting the boundary conditions,the finite element model of the Reduction Malarplasty with L-shaped Osteotemy was established.The FEA model was carried out biomechanical analysis under the load of simulated zygomatic pressure.Results The finite element model established in this study has high geometric and mechanical similarity.The zymomatic pressures performed in operation caused a single stress concentration on the root of the zygomatic arch,and an inward displacement of the malar complex.Conclusion Pressing the zygoma in the Reduction Malarplasty with L-shaped Osteotemy can lead to an expected greenstick fracture just on the root of the zygomatic arch,which result in an inward and lower deformation.