下颌角稳定型骨折坚强内固定后对髁突影响的有限元分析

Finite Element Analysis of Stress Distribution on Condyloid Process after Internal Rigid Fixation of Mandibular Angle Stabilizing Fracture

目的:分析下颌角稳定型骨折坚强内固定以后对髁突应力分布的影响,探讨下颌角骨折引起颞下颌关节紊乱病的生物力学机制。方法:采用螺旋CT技术、计算机图形图像处理功能、有限元处理分析软件Ansys建立下颌骨正常有限元模型及下颌角骨折有限元模型并模拟坚强内固定,定量对比分析髁突应力分布状况。结果:患侧髁突表面应力分布发生了明显改变,尤以髁突前斜面和嵴顶部最为显著;健侧髁突表面应力分布未发生明显改变。结论:下颌角稳定型骨折在外斜线行坚强内固定后髁突表面应力分布发生了异常改变,破坏了颞下颌关节的生物力学环境,可能是下颌骨损伤后颞下颌关节紊乱病的致病原因之一。

Objective： To analyze stress distribution in mandibular condyloid process and realize the possible biomechanical mechanism of the temporomandibular joint disorders （TMD） caused by mandibular angle stabilizing fracture. Methods： Spire CT scan image ,computer image technique and finite element method were used to construct three-dimensional finite element models of normal human mandible and mandibular angle fracture with internal rigid fixation. Stress distribution in mandibular condyliod process of the two models were analyzed and compared. Results： In the injured side, the stress changed obviously, especially in anterior oblique surface and transverse ridge of condyloid process. In the unin- jured side, the stress only locally changed in lateral of posterior oblique surface. Conclusion： The change of stress in condyloid process, after internal rigid fixation of mandibular angle stabilizing fracture, may damage the biomechanical environment of condyie and it may be one of reasons that cause to TMD.