后倾曲作用下上颌支抗磨牙运动趋势的三维有限元法研究

目的分析Ｂｅｇｇ技术第一期后倾曲作用下上颌支抗磨牙的运动趋势。方法三维有限元法，模型采用中国人上颌第一磨牙平均几何尺寸，包括５１６个单元，１１２８个节点。结果牙体瞬间转动中心是一个范围，位于根分叉处偏近中颊根及舌侧根区域的牙槽骨中。牙体呈现出“螺旋式”不平衡近中舌向旋转伸长趋势，伸长的量从多到少顺序：近中颊尖、近中舌尖、远中颇尖、远中舌尖。结论支抗磨牙的各部分运动趋势不平衡。

The study of movement tendancy of maxillary anchorage molar by FEM

Objective To investigate the tendancy of maxillaly first molar by anchorage bend at the fixed appliance Method the three-dimensioal finite element method. The three-dimensional finite element model was constructed on the basis of average anatomic morphology of Chinese maxillary first molar, and consisted of 516 poparametric el-ements. Results 1. The Center of rotation was an area located at the alvelarbone under the trifurcation near the mesio - buccal root RM and palatal root. 2. The tendancy of the molar movement was a spiral rotation together with unequivalent extrusion movement. As to the amount of extrusion, the most is CrispMB, second CrispMR, third CrispDB, the last CrispDR. Conclusion The tendancy of the movement for the anchorage molar were unequivalent.