【摘要】 目的 :分析Begg细丝技术第一期上颌支抗磨牙及其支抗组织的生物力学效应。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 5 16个单元。结果 :1.支抗磨牙所受的合力为伸长力 ,牙及牙周组织的应力分布不均匀 ,拉应力、压应力混合存在。 2 .根分叉周围是应力集中区和缓冲带。 3.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上升趋势。结论 :支抗磨牙及其牙周组织应力复杂 ,牙的各部分运动趋势不平衡 ,且提示上述结论同样适合于方丝弓技术。更多还原

【Abstract】 Objecive:This study was designed to investigate the biomechanical effect induced in maxillary first molar and its periodontal tissue by anchorage bend at the Begg technique stage. Methods: The three-dimensional finite method. The three-dimensional finite element model was constructed on the basis of average anatomic morphology of the Chinese maxillary first molar, and consist of 516 ispoparametric elements.Results : The stress were nonuniform, the tensile stresses and the compressive stresses existed intermingly. It was trifurcationarea that stresses were concentrated in. The join force was an extrusion force. The center of rotation was an area located at the alvelar bone under the trifurcation near the mesiobuccal root and palatal root. The tendency of the molar movement was a spiral rotation unequivalent extrusion movement. Conclusion: The stresses were complicated.The tendency of the archonege molar were unequivalent. The above results provided a reference for Begg technique and edgewise technique.更多还原