舌侧矫治上颌第一磨牙近中移动的有限元分析

目的：用有限元方法研究舌侧矫治上颌第一磨牙近中移动的规律,并与颊侧矫治相比较。方法：通过三维激光扫描,运用CAD软件CATIAV5和有限元软件MSC.PATRAN,建立上颌第一磨牙、牙周膜、牙槽骨及矫治器的有限元模型,分别对其进行不同方式的加载和位移计算。结果：近中水平力作用下,舌侧加载牙近中倾斜伴远中舌向旋转,颊侧加载牙近中倾斜伴近中舌向旋转,其中颊侧加载的倾斜度及旋转度大于舌侧加载。欲使水平向整体移动时,颊侧加载Mt/F=8.1∶1,Mr/F=8∶1。舌侧加载Mt/F=6.9∶1,Mr/F=7.1∶1,且舌侧加载的位移大于颊侧加载。结论：近中整体移动上颌第一磨牙时,舌侧加载效率高于颊侧加载。

A 3-dimensional finite element analysis of displacement of maxillary first molar on mesial movement in lingual orthodontics

PURPOSE: To analyze the displacement of maxillary first molar on mesial movement by lingual technique with the finite element method,and compare with that by labial technique. METHODS: The finite element model was built using the advanced 3-dimensional laser scanning, comprising a maxillary first molar, periodontal ligament, alveolar bone, and a lingual or buccal tube. Different kinds of loads were applied at a point of the lingual or buccal tube separately. By finite element method,the displacement of maxillary first molar was calculated and analyzed. RESULTS: When the mesial force was applied to the maxillary first molar,the tooth was tipped mesially, rotated distally and lingually by lingual technique. By the labial technique,the tooth was tipped mesially, rotated distally and buccally. The degree of tipping and rotation by labial technique was bigger than that by lingual technique. By labial technique, Mt/F=8.1:1,Mr/F=8:1. By lingual technique, Mt/F=6.9:1,Mr/F=7.1:1. When the tooth moved bodily,the displacement of lingual technique was larger than that by labial technique. CONCLUSIONS: When the maxillary first molar moved bodily toward mesial direction, lingual orthodontics is more efficient than labial orthodontics.