儿童切牙整体移动诱导方案的验证和评价

目的 对切牙整体移动的儿童诱导方案进行可行性、有效性分析和评价，估算和分析牙齿表面所受力的大小、方向以及位置。方法 采用CT扫描一个正畸儿童患者的下颌，由此建立下颌切牙、牙周膜、牙槽骨的三维实体模型。然后,通过有限元软件Abaqus计算得到牙周膜外表面的初始应变分布，并将牙周膜外表面的正应变作为牙移动的外部骨重建激励，模拟分析连续更换两次诱导器的诱导效果。结果 牙齿的每周移动量约为0.27 mm，1个诱导周期即1个月移动的总位移量约为1 mm，与实际临床上诱导的效果吻合。结论 本研究结果验证了儿童诱导器对切牙的整体移动具有可行性，为临床的诱导方案制定和优化提供了参考。

Verification and evaluation on induction scheme for bodily movement of incisor in children

Objective In order to analyze and evaluate the feasibility and effectiveness of induction scheme for bodily movement of incisor in children, the size, orientation and position of the force on tooth surface were estimated and analyzed. Methods The orthodontic jaw from a child was scanned to establish the 3D solid model including mandibular incisor, periodontal ligament and alveolar. Initial strain distributions on outer surface of the periodontal ligament were calculated by software Abaqus, and then the positive strain as the stimulation of the tooth movement was used to simulate the inducted effects from the inducer which was changed twice in succession. Results The rate of orthodontic tooth movement was about 0.27 mm per week, and the total displacement during an induction period was about 1 mm per month, showing it was in accordance with the real inducted effects in clinic. Conclusions The present study proved the feasibility of induction scheme for bodily movement of incisor in children and provided reference for formulation and optimization of induction scheme in clinic.