Department of Orthodontics, School of Dentistry, University of Queensland, Brisbane, Queensland, Australia.
Department of Orthodontics, School of Dentistry, University of Queensland, Brisbane, Queensland, Australia.
Am J Orthod Dentofacial Orthop. 2022 Sep;162(3):e103-e115. doi: 10.1016/j.ajodo.2022.06.015. Epub 2022 Jul 12.
Rotation of rounded teeth, particularly canines, is reported as one of the most difficult and inaccurate tooth movements with aligners. This retrospective study aimed to assess the accuracy and reliability of prescribed mandibular canine rotation with Invisalign aligners and the influence of attachment type and wear schedule on accuracy.
A sample of 75 subjects with mandibular canines requiring rotation was collected from an existing database. The initial, predicted finish, and achieved finish, were measured using metrology software, and the differences between predicted and achieved mandibular canine rotations were calculated. The sample was divided into 3 groups: optimized rotation attachments using 1-week wear, optimized rotation attachments using 2-week wear, and conventional rectangular attachments using 2-week wear.
Rotation was an underexpressed movement, with an overall median sample efficiency of 75.4%. For all groups, predicted rotation was not equivalent to achieved rotation at a ± 5° equivalence margin. This indicates that none of the Invisalign SmartTrack aligner attachment configurations display clinical accuracy in their predicted rotation. By attachment type, median efficiencies of 81.5%, 76.5%, and 63.1% were found for groups 1-week wear, 2-week wear, and 2-week wear, respectively. By wear schedule, there was no significant difference in efficiency for optimized rotation attachments.
The clinical expression of canine rotation with SmartTrack aligners is less than the prescribed rotation for all attachment configurations. Vertical rectangular attachments were associated with the least accurate expression of prescribed movement. There was no difference in rotation efficiency between 1- or 2-week aligner wear.
带环的圆形牙齿（尤其是尖牙）的扭转被报道为使用隐形矫正器最困难和最不准确的牙齿移动之一。本回顾性研究旨在评估 Invisalign 隐形矫正器对下颌尖牙扭转的预设准确性和可靠性，以及附件类型和佩戴方案对准确性的影响。
从现有的数据库中收集了 75 名需要进行下颌尖牙扭转的患者的样本。使用计量软件测量初始、预测完成和实际完成的位置，并计算预测和实际下颌尖牙扭转之间的差异。该样本分为三组：使用 1 周佩戴方案的优化旋转附件、使用 2 周佩戴方案的优化旋转附件和使用 2 周佩戴方案的传统矩形附件。
扭转是一种表达不足的运动，整体样本效率中位数为 75.4%。对于所有组，在±5°等效边界内，预测的旋转与实际的旋转并不相等。这表明 Invisalign SmartTrack 矫正器附件配置中的任何一种都没有在预测旋转中显示出临床准确性。按附件类型，1 周佩戴组、2 周佩戴组和 2 周佩戴组的效率中位数分别为 81.5%、76.5%和 63.1%。按佩戴方案，优化旋转附件的效率没有显著差异。
对于所有附件配置，SmartTrack 矫正器对尖牙旋转的临床表达都小于预定的旋转量。垂直矩形附件与预定运动的表达最不准确。1 周或 2 周的矫正器佩戴在旋转效率方面没有差异。
