三维有限元法对下颌角骨折内固定的生物力学分析

Biomechanical Study of Rigid Internal Fixation for Mandibular Angle Fracture Through 3-D FEM Simulation

目的应用三维有限元方法,对不同固定方式的下颌角骨折进行生物力学分析,为临床选择下颌角骨折固定方式提供理论依据。方法应用螺旋CT扫描及相关软件,建立下颌角骨折内固定系统三维有限元模型,并利用MSC.Marc软件对模型进行应力分析。结果张力带固定时应力集中分布于钛板中部,而双列小型板固定时最大应力位于上缘钛板中部。张力带固定时骨折断端的最大相对位移大于双列小型板固定。在健侧后牙咬牙合和前牙咬牙合情况下,张力带固定的安全咬牙合力范围分别在102.7 N和40.3 N以下。结论下颌角骨折时,双列小型板固定的稳定性优于张力带固定。选取适当的咬牙合方式,张力带固定也可以达到下颌骨骨折固定的安全范围。

Objective To observe the stress distribution of mandibular angle fracture under different rigid internal fixation （RIF） methods by developing a three-dimensional finite-element method （3-D FEM）. Methods CT scan technology and related software were used to develop a 3-D FEM of mandibular angle fracture under different RIF. On this basis, the mandibular stress distributions were analyzed by MSC.Marc software. Results The yon Mises stress mainly concentrated on the middle of the titanium plate in tension band fixation, while in two mini-plate ~ixation, it concentrated on the middle of the superior titanium plate. In the tension band fixation, the max-values of displacement was more than that in the two mini-plate fixation. When the biting force dropped to 102.7 N （LMOL） and 40.3 N （ICP）, the furthest fracture mobility got into margin of safety under the tension band fixation. Conclusion The two mini-plate fixation was more stable than the tension band fixation. Choosing the suitable occlusion, tension band fixation could also provide sufficient stability for the mandibular angle fracture.