【摘要】 目的:通过建立颞下颌关节-上下颌骨-牙列-矫正装置的有限元模型,分析不同力值的颌间Ⅲ类牵引对颞下颌关节区应力分布和位移的影响。方法:对正常志愿者行多层螺旋CT扫描,提取上下颌骨及牙齿数据,利用mimics软件、Geo-magic逆软件、建立颞下颌关节-上下颌骨-牙列-矫正装置的三维有限元模型,ANSYS软件10.0分析分别加载100g,150 g,200 g力值的长(短)颌间Ⅲ类牵引时,髁突各部分的受力及位移情况。结果:当加载颌间Ⅲ类牵引时,颞下颌关节区应力分布情况为髁突受到的拉应力主要集中在前斜面,压应力主要集中在后斜面,且随着力量的不断增加,髁突前斜面受到的拉应力、后斜面受到的压应力都逐渐增加;颞下颌关节区位移情况为髁突出现后上位移,且随着力量增大,位移量也逐渐增加。加载在同一力值时,长颌间Ⅲ类牵引对髁突作用效果强于短颌间Ⅲ类牵引。结论:颌间Ⅲ类牵引时,颞下颌关节区前部收到拉应力,后部受压力,总体位移方向为后上,出现后上方向旋转。更多还原

【Abstract】 Objective: To establish temporomandibular joint(TMJ)-maxilla-mandible-teeth- appliance model to analyse the influence of stress distribution and displacement on TMJ by different forces of class Ⅲ elastics. Methods: The data of mandibular and teeth were obtained by CT scaning of the healthy volunteers, and the three-dimension finite element models for TMJ-maxilla-mandible-teeth-appliance was constructed with mimics, Geo-magic. The stress distribution and displacement of condyle on the condition of the long (short) class Ⅲ elastics with 100 g, 150 g, and 200 g were analysed by using ANSYS 10.0 software package. Results: When using class Ⅲ elastics, the stress distribution and the displacement on TNJ were acquired .The stretching stress centred on the frontal surface of the condyle, while the compression stress centred on the posterior surface of the condyle. The displacement of condyle was backward and upward. With the force increasing, the influence was more obvious. The effect on condyle with the long class Ⅲ elastics was stronger than the short one when loading the same force on TMJ. Conclusions: The stretching stress centred on the frontal surface of the condyle while the compression stress centred on the posterior surface of the condyle, and the condyle rotated backward and upward with direction of displacement when using class Ⅲ elastics.更多还原