个体化舌侧矫治器微种植体支抗滑动法内收上前牙的三维有限元模型的构建

目的建立包含eBrace托槽、牙、牙周膜、牙槽骨、弓丝和微种植体在内的三维有限元模型，为分析个体化舌侧矫治器上颌腭部不同位置微种植体滑动法关闭上前牙间隙的生物力学特征做准备。方法依据eBrace个体化舌侧矫治器的设计特点，基于CT采集的实际数据，先建立实体模型，再构建含有牙、牙周膜、牙槽骨、托槽、弓丝和微种植体6个成分的个体化舌侧矫治系统的三维有限元模型。结果1．根据微种植体植入位置不同，共建立6个有限元模型，微种植体分别位于上颌第二双尖牙和第一磨牙间、第一磨牙和第二磨牙间距离牙槽嵴顶2mm、6mm和10mm。每个模型包括40个实体模型。2．用10节点四面体单元进行单元剖分，第一个模型（微种植体在上颌第二双尖牙和第一磨牙之间距离牙槽嵴顶2mm）在网格剖分后有节点741670个，单元513925个。其他模型的节点数和单元数类似。结论建立了包含eBrace托槽、牙、牙周膜、牙槽骨、弓丝和微种植体在内的三维有限元模型，该有限元模型构建全面、复杂、真实，几何相似性很强；为下一步分析个体化舌侧矫治器上颌腭部不同位置微种植体滑动法关闭上前牙间隙的生物力学特征奠定了基础。

An 3-D finite element model of customized lingual bracket system in retracting maxillaryanterior teeth using micro-implants and sliding mechanism

Objective To construct an 3-D FEM model including e-Brace brackets, dentition, periodontal ligaments, alveolar bone, lingual wires and micro-implants to analyze the biomechanical characteristics of the customized lingual bracket system during retracting maxillary anterior teeth at different micro-implant loading positions. Methods Volume models of the interested parts were first constructed based on CT scan data. Then the finite models of customized lingual system, including eBrace brackets and wires, dentition, periodontal ligaments, alveolar bone, and micro-implants were constructed. Results 1. Six 3-D FEM models were constructed at different micro-implant loading positions. The micro-implants were either between the second premolar and the first molar or the first molar and the second molar, at 2 mm, 6 mm or 10 mrn levels from the alveolar ridge crest. Every 3-D FEM model includes forty volume models. 2. Ten-node tetrahedron analysis of the 3-D FEM model includes 741670 nodes, 513925 elements at the micro-implant loading position between the second premolar and the first molar, 2ram from the alveolar ridge crest. The other 3-D FEM models include similar nodes and elements at different micro-implant loading positions. Conclusions The originated eBrace customized lingual 3-D FEM model has high geometrical similarity, and is hence reasonable, reliable and practical. It could be used to analyze the biomechanical characteristics of the lingual system durirm retracting anterior teeth with micro-implants and sliding mechanisms,