目的应用无单元-有限元耦合法探讨正常人牙尖交错位紧咬牙时颞下颌关节内的应力分布情况。方法利用中国可视化人体图像数据建立包括上下牙列、下颌骨、颞下颌关节在内的三维有限元模型和三维无单元-有限元耦合模型,用自行编制的耦合程序对已建立的正常颞下颌关节三维无单元-有限元耦合模型进行应力分析。结果无单元-有限元耦合模型与有限元模型所反映的颞下颌关节应力分布特点基本相同,但耦合模型对关节盘的应力分析更精细。颞下颌关节关节盘最薄弱的中间带区是应力最集中的地区,双板区也是高应力分布区,提示这两处是关节盘最易受损伤的区域。结论无单元-有限元耦合法是一种有效的数值模拟方法,计算过程大大简化,计算精度显著提高,在生物力学研究中有推广应用前景。
Objective To investigate the stress distribution in the normal temporomandibular joint (TMJ) during clenching using a coupled meshless-finite element method. Methods On the basis of images of the Chinese Visible Human, the three-dimensional finite element model and the coupled three-dimensional meshless-finite element model were established, including dentures, mandible, TMJ and so on. The stress distribution in the coupled three-dimensional meshless-finite element model of the normal TMJ was analyzed by a self-developed processor. Result The stress distribution analyzed by the coupled meshless-finite element model was consistent with what was analyzed by the finite element model. However, the former was more precise than the latter: the highest stress region was distributed at the top of the intermediate zone which was the weakest area of the TMJ. Another high stress region was observed in the bilaminar region. All the results suggested that the intermediate zone and the bilaminar region were the most damaged areas. Conclusion We can reasonably conclude that the coupled meshless-finite element method is an effective tool for numerical simulation, and the process of calculation is more simplified and the precision is raised significandy. The coupled meshless-finite element method is able to be successfully applied in other fields within biomechanics.