基于牙颌模型的正畸弓丝初始回复力口外测量技术

The Extra-Oral Measuring Technique of Initial Restoring Force Produced by Orthodontic Archwire Based on Dental Model

目的利用模拟牙颌模型实现正畸弓丝初始回复力的口外测量。方法以1例临床病例作为研究对象,通过3D打印制作与患者真实牙列分布相一致的上颌牙颌模型,并以此为基础利用Nano17 F/T力学传感器搭建矫治力测量系统,测量直径为355. 6μm标准圆镍钛弓丝佩戴在牙颌模型上后施加在患者2颗上颌中切牙上的初始回复力。结果患者上颌中切牙21受到的初始矫治力较中切牙11更大,且2颗中切牙所受到的矫治力系均不利于牙齿的理想移动,需要添加辅助装置改善牙齿受力状况。在优化正畸治疗方案后,患者在治疗18个月后获得满意的矫治效果。结论利用患者的模拟牙颌模型可以准确测量正畸弓丝作用在目标牙齿上的矫治力系,预估牙齿的移动形式,并以此为基础改进牙齿矫治方案。矫治力的口外测量技术为临床正畸治疗提供重要参考,为矫治方案的优化设计开创新思路。

Objective To realize the extra-oral measurement of initial recovery force produced by orthodontic wire using simulated dental model.Methods A clinical patient was selected as the study objective,and maxillary dental models,which were in accordance with the real dentition of patient,were fabricated by three-dimensional printing.An orthodontic force measuring system was constructed using Nano17 F/T mechanical sensors to measure the initial recovery forces on two maxillary central incisors,which were produced by a standard circle Ni-Ti wire with the diameter of 355.6μm after the archwire was assembled on the dental model.Results Central incisor 21 suffered a lager initial orthodontic force compared with incisor 11,and the force systems on two incisors were both adverse to tooth ideal movement,therefore,an assistive device was necessary to improve force status of the teeth.When the orthodontic treatment plan was optimized,a satisfactory result was obtained after 18 months of treatment.Conclusions Force systems caused by orthodontic wire and exerted on the teeth could be accurately measured using the simulated dental model of patient,so as to predict the teeth moving type,and improve teeth treatment plan on this basis.The extra-oral measuring technique of orthodontic force provides an important reference for clinical orthodontic treatment,and creates a novel idea for the optimal design of orthodontic plan.