上颌骨缺损颧种植体功能设计及生物力学评价

Functional Design and Biomechanical Evaluation of the Maxillary Reconstruction with Zygoma Implant

利用Branemark颧骨种植体,结合显微外科骨移植技术重建半侧缺损和全缺损上颌骨的形态和功能,并对重建的生物力学效果进行评价.基于CT扫描和图像及图形处理技术,建立标准人的模块化颅骨三维几何和有限元力学模型.基于该模型,模拟不同颌面骨缺损状态,设计上颌骨半侧和全缺损颧种植体长度、植入位置、植入方向,及常规种植体分布和数量,并利用有限元方法评价该设计的生物力学性能.结果表明,腓骨移植Branemark颧骨种植体种植修复半、全侧上颌缺损模型的应力分布中,应力最大值出现在颧种植体植入颧骨的颈部,颧种植体上应力值较周围支持组织的大,起到了颧突支柱对牙合力的传导作用;种植体结构中弯曲变化的位移不明显,并且种植体整体位移在颧骨附近逐渐减小为零.故腓骨重建颧种植修复上颌骨缺损方法能够有效传导牙合力,其周围支持组织具有良好的应力分布,是一种安全有效修复上颌缺损、恢复咀嚼功能的临床方法.

Biomechanical evaluation and functional design ot the maxillary reconstruction memoa using me microsurgery fibula graft and Branemark zygoma implant were studied. Based on the CT scan and the image process technology, a modularized geometrical and finite element model of the human skull was built to simulate various defect patterns of the maxillary and design the position, direction, length of the zygoma fixture, and the number of the conventional fixtures. Biomechanical properties of the design were evaluated using finite element analysis （FEA） method. The findings are as follows. The highest stress peaks concentrate at the neck of the zygoma fixture on the zygoma, while the rest of the peri-implant bone appears to bear lower stress. The zygoma fixture plays a role in transmitting the occlusal force substituting the zagomatic process brace. The deformation tendency of the implants is identical, the displacement of bending is not obviously observed. The displacement of the zygoma fixture near the zygoma is greatly decreased to zero. The results show that the transmission of the occlusal force and stress distribution of the peri-implant bone of this repair method is very satisfying. The maxillary repair method using the microsurgery fibula graft and Branemark zygoma implant is secure and feasible.