内收前牙时微种植钉调控牙合平面的有限元分析

摘要

Objective:To investigate the changes of occlusal plane in the process of retracting maxillary anterior teeth with different vertical traction force.Methods:The three dimensional finite element model of maxillary anterior teeth en-masse retraction by micro-implant was constructed with cone beam CT scanning and MIMICS and ANSYS software.Then the movement tendency of tooth and the changes of the maxillary occlusal plane was calculated when the vertical traction force was 0,0.5,0.75 and 1 N in the process of en-mass retraction,respectively.Results:Lingual tipping of anterior teeth,distal tipping of the first molar and the maxillary occlusal plane clockwise rotation by the retraction forces were observed.With the vertical traction force increasing,lingual tipping of anterior teeth and distal tipping of the first molar were decreased,and the occlusal plane clockwise rotation was prevented.Conclusion:The upper dentition movement and occlusal plane rotation can be changed effectively by the vertical traction with different force.When retract anterior teeth,0.5-0.75 N vertical traction force is beneficial to prevent clockwise rotation of the maxillary occlusal plane.%目的:探讨内收上前牙过程中,前牙区不同大小压低力对上颌平面变化的影响.方法:应用CBCT扫描、MIMICS以及ANSYS等软件建立微种植钉内收前牙的三维有限元模型,设置前牙区分别为0、0.5、0.75、1 N的压低力,计算分析前后牙的位移趋势以及平面的变化.结果:单纯的内收力使上前牙舌倾、第一磨牙远中倾斜、上颌平面顺时针旋转.随着前牙区压低力增大,上前牙舌倾程度降低,接近整体移动,第一磨牙远中倾斜移动的趋势减小,平面顺时针旋转的情况得以抑制.结论:通过改变前牙区压低力的大小,可以有效地改变上颌前牙的移动方式及平面的旋转;在内收前牙时增加0.5~0.75 N压低力,更有利于防止上颌平面的顺时针旋转.