颞下颌关节与咬合关系研究三维有限元模型的建立

目的：建立生物相似性和力学相似性都较高的、包括下颌骨和颢下颌关节(TMJ)的计算机三维有限元模型。方法：以正常咬合、青年尸体头颅为标本，用CT断层和手工断层相结合的方法分别建立下颌骨及TMJ硬、软组织模型，并给髁突赋予实验测得的正交各向异性参数；以光弹实验测得的咬合力向量进行加载，以二维平衡力系计算结合约束的方法进行边界约束。结果：建立了包括下颌骨、髁突、关节盘、关节软骨的三维有限元模型，并真实再现了同一个体的盘-突关系。结论：本研究可有效地提高下颌骨及TMJ有限元模型的生物及力学相似性，为一系列咬合对TMJ应力影响的生物力学研究奠定基础。

Establishment of three-dimensional finite element model of TMJ for relation analysis with occlusion

Objective: To establish the three-dimensional finite element model of mandible and temporomandibular joint (TMJ),which has higher similarity to the real TMJ in vivo. Methods: A young skull with normal occlusion was adopted for CT scanned transverse section and manual slice section to establish hard and soft tissue of TMJ respectively, in which the condyle was defined as orthotropic material. Contraction and dynamic equilibrium calculation were both used for boundary condition. The whole model was loaded with the occlusal vector resulting from photoelastic analysis. Results: The three-dimensional finite element model including mandible, condyle, disc and articular cartilage was established, in which the normal condyle-disc relationship in real TMJ in vivo was present. Conclusion: The above-mentioned methods could improve the biomechanical similarity of finite element model of mandible and TMJ effectively, which establishes good foundation for a series of biomechanical studies on effects of occlusion to TMJ stress.