下颌骨撞击试验与有限元分析

目的 利用MTS-858生物材料试验机进行下颌骨撞击试验和三维有限元分析方法揭示下颌骨骨折生物力学机制.方法 根据Hanau合架原理,3例标本分别制备成下颌骨撞击模型,MTS-858生物材料试验机进行下颌骨颏部水平方向撞击试验.人体下颌骨标本利用激光三维扫描系统获得下颌骨模型,有限元软件ANSYS7.0分析.结果 3例标本均在颏部骨折,下颌骨颏部撞击力峰值为(2151.10±125.18)N;响应时间为(17.3±2.3)ms.ANSYS动态显示下颌骨颏部受到撞击后下颌骨内部的应力变化,颏部撞击点应力最大,应力变化曲线显示在颏部距上缘1.92 cm处出现峰值,最大应力为3201.35 kPa.结论 下颌骨撞击试验和三维有限元方法结合量化了颏部受力下颌骨骨折的有关参数,为揭示任意合位下颌骨撞击下颌骨骨折的生物力学机制奠定基础.

Finite element analysis of the biomechanics of human mandible in response to impact force

OBJECTIVE: To explore the biomechanical mechanism of impact force-induced mandibular fractures and its finite element analysis. METHODS: Three mandibular impact fracture models were prepared using intact human mandibular specimens and simulated maxillary models according to the Hanau principle of articulator and a MTS-858 biological material testing machine. Mandibular impact was delivered in the direction of the chin level at the mandibular postural position (MPP) on MTS. The computerized mandibular model was then established from 3-dimensional laser scanning images for finite element analysis using ANSYS7.0. RESULTS: The 3 mandibular specimens were fractured at the chin, where the maximum force was 2151.10-/+ 125.18 N with response time of 17.3-/+2.3 ms. Impact simulation with ANSYS mimicking stress changes in the internal jaw suggested the chin as place where maximum stress occurred. According to the stress curve, the maximum stress of 3201.35 kPa occurred at the point 1.92 cm from the upper edge of the chin. CONCLUSION: The combination of mandibular impact experiments and finite element analysis allows quantification of several parameters of the jaw and provides clues for understanding the biomechanical mechanism of mandibular impact fractures.