上颌复合体两种工况下眶区有限元分析

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。

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

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.