双丝弓个性化舌侧托槽的计算机辅助设计

目的实现一种个性化托槽的计算机辅助设计，以便在临床矫治中显著减小前牙控根力，并且能够应用于拔牙病例。方法在包括患者牙根的整合牙颌模型上进行虚拟排牙，在排牙后的模型上绘制直丝弓和设计双丝直丝弓托槽，托槽通过托槽体的厚度补偿来实现弓丝的直丝化，在托槽上设计双槽沟，主槽沟为方槽沟，辅槽沟为圆槽沟，在主槽沟用方丝虚拟定位托槽后，用计算机辅助设计和制作的个性化托槽，将托槽的虚拟位置转移到患者牙齿上的实际粘接位置进行矫治。结果与方丝控根相比，双丝控根矫治力显著减小；唇侧或舌侧矫治时可以使用直丝弓，简化了临床弓丝弯制；虚拟排牙基于3D整合牙颌模型，可以在虚拟排牙中避免牙根的骨开裂、骨开窗和明显不平行。结论本研究为双丝弓个性化托槽的临床应用奠定了基础。

Computer aided design of customized straight and double wire brackets

Objective To achieve computer aided design of customized straight and double wire brackets for both extraction and non-extraction cases to reduce the force of torque. Methods We selected one lingual orthodontic patient to integrate the cone bean computerized tomography （CBCT）-based bone models and laser-scanned dental models. The setup based on 3D integrated maxillofacial-dental models was finished with consideration of roots and alveolar in good dimensional relationship. The bracket bases were generated on the lingual surfaces of the teeth in digital model after setup. Bracket bodies with double slots and individualized straight archwires were designed by software. After positioning, the bracket bodies were virtually fused with the bracket bases. We designed individualized brackets with twin slots based on this setup model. Results The customized straight and double wire brackets for both extraction and non-extraction cases were designed, which reduced the force of torque significantly. Conclusion It is feasible to design customized straight and double wire brackets for both extraction and non-extraction cases to reduce the force of torque.