人下颌骨撞击伤有限元模拟及生物力学研究

Biomechanical study on the impact injure of human mandible by finite element method

目的:利用有限元法建立人颌骨模型,动态模拟不同撞击力致伤下颌骨,探讨撞击伤发生时,下颌骨生物力学变化。方法:依据正常成人颌面部CT扫描数据,利用Mimics等软件建立人颌骨有限元模型,在LS-DYNA等软件中模拟撞击物以不同条件致伤人下颌骨的过程,分析损伤过程中下颌骨生物力学变化。结果:建立了人颌骨有限元模型,模拟了不同撞击力致伤人下颌骨的过程;下颌颏部、下颌角及髁突颈部为应力集中区;离撞击部位越近,质量越大,速度越大,应力峰值越大。撞击伤应力由撞击点呈放射状向四周传导,传导中应力逐渐减小。横截面积较小的部位易出现应力集中,损伤最严重。结论:撞击物的质量、速度、撞击角度是损伤严重程度的影响因素。

Objective： To investigate biomechanical changes of mandible in the impact injure simulated by finite element method（ FEM）. Methods： Mimics and Comsol software were used to build a FEM of human craniofacial bone based on CT scan data of a normal adult. LS-DYNA and Hypermesh software were used to simulate the impact with different quality,velocity and angulation produced injures of human mandible,the biomechanical parameters of the mandible in the impact injury process were analysed. Results：A FEM of human maxillofacial bone was established,and the dynamic process of different impact force produced damage was simulated. Mandibular chin,angle and condylar neck was the stress concentrated area in the process of mandible injury. There was higher stress peak at the site which was closer to the impact position,the stress peak arrival time was also earlier. When the impactor with the same quality,the bigger the velocity,the greater the stress peak. When the impactor with the same velocity,the bigger the quality,the greater the stress peak. When the impactor with the same velocity and quality,there was greater stress peak under the impact to mandible from angulation of 0 degree. Stress transfered to the surrounding bone from the impact position radially and gradually reduced. The bone area with small cross-section was prone to high stress and more serious damage. Conclusion： The quality,the velocity,the impact angle and the impact site are the factors affecting the severity of impact injury.