两种隐形正畸序列磨牙远移的有限元比较

目的 比较两种远中移动序列的无托槽隐形矫治在磨牙远移方面的执行效果。方法 建立包含牙体、牙周膜、牙槽骨及隐形矫治器的下颌右侧7颗牙齿有限元模型，分别选用两种推磨牙远中移动对牙齿进行模拟第二磨牙远移0.5 mm的过程，采用牙槽骨重建技术模拟长期牙齿移动效果。结果 V型、ZC远中移动序列第二磨牙最大远中位移分别为0.27、0.34 mm, ZC远中移动执行效率增大13.34%;牙齿内倾分别矫正0.18、0.44 mm,舌侧内倾角度分别矫正1.15°、2.69°,ZC舌侧内倾矫正率提高15.01%;远端倾斜分别增大1.83°、0.84°,ZC远端倾斜角度减小54.10%。结论 ZC远中移动序列方法在无托槽隐形矫治中能够更有效地实现磨牙远中移动，减少磨牙远中倾斜和矫正磨牙舌侧内倾，为无托槽隐形矫治创造前牙间隙提供有利条件。

Molar Distalization with Two Invisible Orthodontic Sequences: A Finite Element Comparison

Objective To compare the effects of clear-aligner orthodontics with two orthodontic sequences on molar distalization. Methods A finite-element model of seven right mandibular teeth with periodontal alveolar bone and braces was established. Two molar distalization sequences were selected to simulate the distal movement of the second molar (0.5 mm), and the long-term tooth movement was simulated using the alveolar bone reconstruction technique. Results The maximum distal displacement of the second molar with V-pattern and ZC sequences was 0.27 mm and 0.34 mm, respectively, and the ZC distal displacement efficiency was increased by 13.34%. The tooth inclination was corrected by 0.18 mm and 0.44 mm, the lingual inclination was corrected by 1.15° and 2.69°, respectively, and the correction rate of ZC lingual inclination was increased by 15.01%. The distal tilt of the ZC increased by 1.83° and 0.84°, and the distal tilt of the ZC decreased by 54.10%. Conclusions The ZC sequence method can realize distal molar movement more effectively, reduce the distal inclination of the molar, and correct the lingual inclination of the molar, providing favorable conditions for orthodontic treatment of anterior teeth.