下颌骨颏部正中牵张成骨过程中颞下颌关节的应力分布

Three-dimensional finite element stress analysis of the temporomandibular joint during mandibular osteodistraction

目的 :建立包括下颌骨的颞下颌关节 (TMJ)三维有限元模型 ,分析该模型在下颌骨颏部正中牵张成骨过程中颞下颌关节的应力分布特征 .方法 :以活体人颅为标本 ,用螺旋CT扫描技术、图形数字化处理在计算机上建立模型 ,然后在下颌骨颏部正中行水平加载 ,采用ANSYS6 .1有限元分析软件进行分析 .结果 :建立了包括下颌骨的TMJ有限元模型 ,在此模型上进行下颌骨颏部正中牵张成骨的力学加载 ,此时颞下颌关节的应力分布表现为 :随着加载力值的增加 ,关节内压应力、拉应力的大小也随着增加 ,但分布区域不变 .压应力和拉应力均表现为外侧高于中、内侧 .结论 :在下颌骨颏部正中行牵张成骨时 ,结果提示TMJ内最大压应力部位在髁突软骨的外后 ,最大拉应力部位在髁突软骨的内前 。

AIM: To establish a temporomandibular joint (TMJ) model including mandible by means of three dimensional finite element methods and to analyze the stress distribution of TMJ during mandibular distraction osteogenesis in the middle of the chin. METHODS: The three dimensional finite element model was developed by helix CT scanning and the stress distribution was analyzed by three dimensional finite element method. RESULTS: In this model the stress values increased with the increasing loads but the distribution area was invariable. The exterior stress was greater than the interior or the middle. CONCLUSION: The maximal compressive stress may distribute in the posterior exterior condylar cartilage and the maximal tensile stress may distribute in the interior anterior condylar cartilage.