目的：通过三维有限元技术，分析不同控根附件在无托槽隐形矫治远中移动尖牙过程中的控根效果。 方法：通过三维有限元技术，建立了由4种附件（A附件—无附件（空白组）；B附件—传统垂直矩形附件；C附件—1/4球形双优化附件；D附件—门拱形双优化附件）和3种载荷（a —矫治器预设0.15mm的远中位移；b —a+对附件受力面施加 30N·mm 的逆时针力矩；c —a+对整个牙冠施加 30N·mm的逆时针力矩）组成的11组模型。模拟右上颌尖牙在不同载荷的无托槽隐形矫治作用下，远中移动的控根效果。 结果: 所有模型的位移模式均为远中倾斜移动。对比空白组Aa（A附件上施加a载荷）旋转中心的位置及以旋转中心到根尖的变化率，发现门拱形双优化附件远中移动尖牙时控根效果最佳。两组双优化附件控根效果优于传统矩形附件。添加附件对尖牙的控根效果明显优于只施加逆时针力偶。 结论: 结合临床，本研究认为无托槽隐形矫治治疗尖牙远移时，提高控根能力最适合的措施是使用门拱形双优化附件。
PURPOSE: Through the three-dimensional finite element technique, the root control effects of different root control attachment on canine translation were analyzed in plastic aligner-based orthodontic technology. METHODS: Through three-dimensional finite element technology, 11 models composed of 4 accessories and 3 loads were established.(A attachment-- no attachments (blank group); B attachment -- traditional vertical rectangular attachment; C attachment-- 1/4 spherical double-optimized attachment; D attachment -- double optimized door arch attachment；a -- 0.15mm remote displacement of canine; b--a+a counterclockwise torque of 30*mm is applied to the stress surface of the attachment；c--a+ a counterclockwise torque of 30*mm is applied to the entire crown ).The root control effect of remote movement of the right maxillary canine was simulated under the effect of plastic aligner under different loads. RESULTS: All models of displacement mode are tipped distally movement.By comparing the position of rotation center of Aa (A load applied on attachment A) in blank group and the change rate from rotation center to root tip, it was found that the combination of the double-optimized attachment of the door arch exerted A counterclockwise torque on the whole crown, and the root control effect was the best when the canine was moved distally, with no significant difference from the 1/4 spherical double-optimized attachment.The root control effect of two groups of double-optimized attachment is better than that of traditional rectangular attachment. The effect of adding attachments on root control of canine is better than that of applying only counterclockwise couple. CONCLUSIONS: Combined with clinical, the guiding significance of this study is that the most suitable measure to improve the ability of root control when treating canine distal movement is to use the double optimized door arch attachment.