螺旋器分裂基托式矫治装置远移上颌第一磨牙的三维有限元分析

Three dimensional finite element analysis of distal maxillary first molars with screw split-base appliance

目的探讨螺旋器分裂基托式矫治装置远移上颌第一磨牙0.2 mm时,上颌第一磨牙的位移趋势和牙周组织的应力情况。方法将患者颌面部CBCT数据导入Mimics 20.0软件进行处理,利用Geomagic Studio 2014逆向工程软件以及NX 1911软件进行几何以及实体建模,建立上颌骨-上牙列-牙周膜-黏骨膜-螺旋器分裂基托式矫治装置的模型,采用有限元软件Ansys Workbench 2019对螺旋器分裂基托式矫治装置模型实施远中移动上颌第一磨牙0.2 mm的工况,探讨上颌第一磨牙的位移趋势、应力大小以及牙周膜的应力分布情况。结果(1)螺旋器分裂基托式矫治装置远移上颌第一磨牙的单次位移量较大,牙齿偏向倾斜移动。(2)螺旋器分裂基托式矫治装置远移上颌第一磨牙时,应力主要分布在上颌第一磨牙上,且等效应力最大值位于第一磨牙远颊根的根分叉处。结论螺旋器分裂基托式矫治装置建议用于远移牙根发育完全的第一磨牙且第一磨牙近中倾斜的病例。

Objective To investigate the displacement trend of maxillary first molar and the stress of periodontal tissue when the screw split-base appliance was moved 0.2 mm away from the maxillary first molar.Methods Cone-beam CT(CBCT)was used to scan volunteers'maxillofacial oral conditions.Mimics 20.0 software was introduced to process the CBCT data.Geometric and physical modeling was performed using Geomagic Studio 2014 reverse engineering software and NX 1911 software.The model of maxilla-upper dentition-periodontal membrane-mucperiosteum-screw split-base appliance was established.The finite element software Ansys Workbench 2019 was used to move the model of screw split-base appliance to the maxillary first molar by 0.2 mm.The displacement trend,stress size and stress distribution of periodontal membrane of maxillary first molar were discussed.Results①The single displacement of distal movement of maxillary first molar with screw splint-based appliance was large,and the teeth tended to move obliquely.②When the appliance was used to remove the maxillary first molar,the stress was mainly distributed on the maxillary first molar and the maximum of the equivalent stress was located at the root bifurcation of the distal buccal root of the first molar.Conclusion The screw split-base appliance is recommended for the treatment of first molar with fully developed roots and mesial inclination of the first molar.