中文摘要：

目的通过对不同关节盘移位的数值模拟，探究各种移位情况下颞下颌关节（temporomandihularjoint，TMJ）内各结构的应力分布规律。方法依据CT图像，建立包含下颌骨、全牙列、关节盘和关节软骨的正常TMJ三维有限元模型；参考天节盘前、后、外、内移位的临床特征，建立对应的4个模型。关节盘与关节软骨问考虑接触，用缆索元模拟下颌韧带和关节盘附着，施加正中咬合荷载。结果前移位将导致关节盘中带产生过高的压应力，达剑3．23MPa；后、内、外移位时关节盘的整体应力水平比前移位和正常TMJ高；各种移位都使关节结节后斜面的应力值大幅度增加，但对髁突关节面的影响却不大。结论各种移位都将导致关节盘和关节结节后斜面产生过高的应力，且后、内、外移位更为危险，更容易造成关节结构和功能的损伤。

英文摘要：

Objective To investigate stress distributions on temporomandibular joint （TMJ） with different disc dis- placements through numerical simulation. Methods A three-dimensional finite element model of normal TMJ in- cluding the mandible, teeth, discs and articular cartilage was established according to CT images of a volunteer with asymptomatic joints. Based on the model, four corresponding models with the anterior, posterior, lateral and medial displacement of the disc were developed. Contact elements were considered to simulate the interaction between the discs and articular cartilages of the condyle and the temporal bone. Cable elements were used to simulate the ligaments and attachments of the disc. The muscle forces and boundary conditions corresponding to the centric occlusions were applied on the models. Results The maximum compressive stress occurred at the intermediate zone due to the anterior displacement of the disc, which was as high as 3.23 MPa. The model with the posterior, lateral and medial displacements of the disc had higher stresses than the model with the anterior displacement of the disc and healthy TMJ model. The stresses at the back of the articular eminences in four mod- els with disc displacements were much hiqher than those in healthy TMJ model. However, the effects of disc dis-placements on the stresses of the condyles were not obvious. Conclusions Disc displacements could cause higher stresses in the discs and at the back of the articular eminences, especially in the model with the posterior, lateral and medial displacements of the disc, which was likely to cause damage to TMJ structure and function.