目的 对下颌角肥大钻凿法截骨整形手术进行生物力学研究,并探索该术式的优化改进。方法 采用有限元方法,建立下颌角钻凿法截骨整形手术及其改良术式的三维有限元模型并进行应力分析、比较。结果 模型-1(钻凿法下颌角截骨整形手术模型)下颌角断裂失效载荷在所有术式中最高,为2426N。其余的改良术式模型(模型-2~7)失效载荷均低于模型-1,分别为2018N、1854N、1447N、1183N、1028N、876N。同时,模型-7与其他模型对比,其应力分布范围最小,关节盘von Mises应力手术侧大于非手术侧,大部分区域为0.52～3.25 MPa之间,最大不超过9.86 MPa。结论 在非均匀钻孔加去下颌角颊侧皮质骨的同时施加最大咬合力和下颌支后缘约束的手术方法最优。

Objective To study the biomechanics of osteotomy surgery for mandibular angle hypertrophy with drilling method and to explore the optimization and improvement of this operation. Methods Using the finite element method, the three-dimensional finite element models of osteotomy surgery for mandibular angle hypertrophy with drilling method as well as its modified operations are established,meanwhile, the stress analysis and comparison are performed. Results Model-1 (mandibular angle osteotomy surgery model by drilling method) had the highest fracture failure load among all surgical methods, which was 2426N. The failure loads of the other modified surgical models (model-2 ~7) were all lower than that of model-1, which were 2018N, 1854N, 1447N, 1183N, 1028N and 876N, respectively. Meanwhile, compared with other models, the stress distribution region of model-7 was the smallest, with the von Mises stress in operating side of the articular disc was greater than that of the non-operating side, and most of the area was between 0.52～3.25MPa and the maximum of 9.86MPa. Conclusion The non-uniform drilling and removal of the buccal cortical bone of the mandibular angle are combined with the maximum occlusal force and the constraint of the posterior margin of the mandibular ramus is the best operation method.