上颌复合体两种工况下应力传导路的研究

目的：了解正常上颌复合体在不同状态条件下的应力分布情况,初步探讨其本身的应力大小、方向及传导路。方法：在自主建立的较理想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,相同载荷时主应力矢量图。结果：正常上颌复合体在正中咬合和张口位两种状态下,双侧第一磨牙加载垂直集中力时,各部位受力是不均匀的。集中表现在上颌骨的三对支柱上。在正中咬合时应力主要沿颧突支柱和尖牙支柱传递;在张口位时,应力在颧突支柱传导比例增大,尖牙支柱上的力减小。结论：尖牙支柱在磨牙受力时也发挥着重要作用,三对支柱不能孤立、割裂地认识,而是一个共同作用的整体。

The finite element analysis of the stress conducting pathway in the normal maxillary complex under the different conditions

Objective;To find the changes of stress distribution in the normal maxillary complex under different conditions and explore the stress conducting pathway in it. Method; Simulating the different boundery conditions during open-mouth position and centric occluding, the characters of stress distribution are analyzed and compared by three dimensional finite element methods. Result; The value of stresses in the normal maxillary complex during centric occluding and open-mouth position, is asymmetry and very small. The normal maxillary complex contains the uniform tress distribution in the different conditions. The three pairs of vertical buttresses in maxilla epitomize this feature. The stress is transmitted mainly along canine buttress and zygomatic buttress during centric occluding. At open-mouth position, the stress at zygomatic buttress is higher and the stress at canine buttress is lower than that at the corresponding site during centric occluding. Conclusion;The results prove the existence of the three pairs of vertical buttresses in maxilla, and show the importance of canine buttress when the first molars are loaded with vertical concentrated pressures. The three pairs of buttress are not isolated and separated, they take effects jointly. We find the function of canine buttress is indispensable no matter which condition is in.