Torque movement of the upper anterior teeth using a clear aligner in cases of extraction: a finite element study

作者：Yuxun Cheng, Jie Gao, Shishu Fang, Zhiyuan Wang, Yanning Ma, Zuolin Jin · 发表于：Progress in Orthodontics · 年份：2022 · DOI：10.1186/s40510-022-00421-8 · 被引用次数：89 · 研究领域：Orthodontics and Dentofacial Orthopedics、dental development and anomalies、Temporomandibular Joint Disorders

BACKGROUND: Clear aligner treatment has become popular over recent years. It is necessary to identify methods by which we could avoid the bowing effect in extractions with clear aligner. The present study was to identify the appropriate method to design torque movement involving the upper anterior teeth of extraction cases, in order to maintain or improve the axis and torque of the upper anterior teeth with a clear aligner during movement and closure of the extraction space. RESULTS: As the height of the power ridge increased, the rotation angle of the upper central incisor in the sagittal direction decreased gradually and the location of the rotation center changed significantly; the rotation center moved in the apical direction and then changed to the crown side. The highest von-Mises stress of the upper central incisor root, periodontal ligaments, and alveolar bone, showed little change as the power ridge height increased. When the axial inclination of the upper central incisor was normal (U1-SN = 105°), the tendency of movement for the upper central incisor approached translation with a power ridge height of 0.7 mm (corresponding distorted angle: 5.8415). When the axial inclination of the upper central incisor was oversized (U1-SN = 110°), the axial inclination of the upper central incisor reduced to normal following completion of the anterior segment retraction with a power ridge of 0.4 mm (corresponding distorted angle: 3.4265). CONCLUSION: Analysis indicates that pure ...