上颌复合体两种工况下眶区有限元分析

Three-dimensional finite element analysis of the orbital region under the same load in different conditions

目的:了解正常上颌复合体在不同状态相同载荷条件下,眶区的应力分布变化情况,进一步探讨其本身的生物力学行为特征。方法:在自主建立的三维有限元模型基础上,利用ANSYS软件分别模拟张口位和正中咬合时,上颌复合体的边界条件,计算并绘制出不同状态相同载荷时各种应力、位移的数据和图像。结果:正常上颌复合体在正中咬合和张口位两种状态下,双侧第一磨牙受垂直集中压力作用,其眶区各部位应力和位移值不仅均较小;而且当受到相同的载荷作用时,其相应部位应力大小及位移值是不相等的。正中咬合时应力值小于张口位,特别是在眶外侧壁区域,这种差异更为显著,且此部位在张口位的位移也大于正中咬合位。结论:正常上颌复合体当双侧第一磨牙受垂直压力时,在不同状态各相应部位的应力和位移大小是不等的。正中咬合状态下,两者均小于张口位。尤其是在眼眶外侧壁上,张口位的应力值显著大于正中咬合位,且张口位位移最大值在视神经孔附近。初步认为,在临床工作中,应避免在张口位给上颌第一磨牙施加过大的垂直压力。

Objective： To find the changes of stress distribution in the orbital region of normal maxillary complex under different conditions and explore the feature of biomechanical reaction. Methods： Simulating the different boundary conditions at open-mouth position and centric occluding, the characters of stress distribution are analyzed and compared by three dimensional finite element method. Results： Under the same load, the stresses and displacements of the same region in the normal maxillary complex were distributed unequally. The limits of stress and displacement at open-mouth position were wider than that during centric occluding. Especially in orbit lateral wall, the stress at open-mouth position was much higher than that during centric occluding. Conclusions： The stress of the whole maxillary complex during centric occluding is lower than that at open-mouth position. The stress at open-mouth position is much higher than that during centric occluding, especially in orbit lateral wall the maximum displacement at open-mouth position is around the foramen opticum.