高速破片冲击猪下颌骨对颞下颌关节损伤机制的研究

摘要

目的:研究不同速度的破片冲击猪下颌骨对其颞下颌关节损伤的力学机制.方法:采用离体新鲜猪头12 只,分为3 组(n=4),分别用1 g圆柱形破片在900、1 200、1 500 m/s下对其右侧下颌角部进行冲击,测量双侧下颌角部、额部的加速度和双侧髁突颈部应变的数据,分析各部位的受力特点.结果:迎弹侧、对侧和颅部加速度之间的比值在低速组为8:1.9:1,在中速组约为9.9:2:1,在高速组约为10.2:2:1.迎弹侧和对侧髁状突颈部应变的比值在低速组约为2.87,在中速组约为2.43,在高速组约为1.70.结论:在下颌骨受到来自侧向的高速破片冲击时,引起髁突颈部线性骨折的侧向力和关节窝损伤的轴向力主要作用在迎弹侧,在对侧也未大量衰减.%Objective:To study the mechanism of the temporomandibular joint(TMJ) trauma caused by the fragment impact with different velocity on pig mandibular.Methods:12 pig heads were penetrated at the right mandibular angle by 1 g cylindrical fragment with the speed of 900,1 200,1 500 m/s(n=4) respectively.The strain of the bilateral condyle necks and the acceleration of the bilateral mandibular angles and the forehead were measured,the stress characteristics of each part was analysed.Results:The ratio of acceleration of impact side the opposite side and the forehead was 8:1.9:1 in the low speed group,9.9:2:1 in the middle speed group and 10.2:2:1 in the high speed group.The ratio of strain of impact side and the opposite side was 2.87 in the low speed group,2.43 in the middle speed group and 1.70 in the high speed group.Conclusion:When the mandibular is impacted by fragment from the lateral,the lateral force which causes linear fracture of condylar neck is mainly on the impact side,the axial force which causes comminuted fracture of condylar neck,as well as on the opposite side.