Abstract：
BACKGROUND: This study aimed to evaluate the effects of varying auxiliaries on tooth movement and stress distribution when maxillary central incisors were torqued 1° with a clear aligner through finite element analysis.
METHODS: Three-dimensional finite element models, including maxillary alveolar bone, periodontal ligament, dentition, and clear aligner, were constructed. According to the auxiliaries designed on the maxillary central incisor, 5 models were created: (1) without auxiliaries (control model), (2) with the power ridge, (3) with the semi-ellipsoid attachment, (4) with the horizontal rectangular attachment, and (5) with the horizontal cylinder attachment. The tooth movement and periodontal ligament stress distribution after a palatal root torque of 1° were analyzed for each of the 5 models.
RESULTS: With 1° torque predicted, the maxillary central incisor without auxiliaries showed a tendency of labial tipping, mesial tipping, and intrusion. The rotation center moved occlusally in the power ridge model. The labiolingual inclination variation increased in the semi-ellipsoid attachment model but decreased in the power ridge model. The maxillary central incisor is twisted in the distal direction in the power ridge model. The maxillary central incisor of the horizontal rectangular attachment and the horizontal cylinder attachment model behaved similarly to the control model. Periodontal stresses were concentrated in the cervical and apical areas. The maximum von Mises stresses were 11.6, 12.4, 3.81, 1.14, and 11.0 kPa in the 5 models. The semi-ellipsoid attachment model exhibited a more uniform stress distribution than the other models.
CONCLUSIONS: Semi-ellipsoid attachment performed better efficacy on labiolingual inclination, and power ridge performed better efficacy on root control. However, a distal twist of maxillary incisors could be generated by the power ridge.
METHODS: Three-dimensional finite element models, including maxillary alveolar bone, periodontal ligament, dentition, and clear aligner, were constructed. According to the auxiliaries designed on the maxillary central incisor, 5 models were created: (1) without auxiliaries (control model), (2) with the power ridge, (3) with the semi-ellipsoid attachment, (4) with the horizontal rectangular attachment, and (5) with the horizontal cylinder attachment. The tooth movement and periodontal ligament stress distribution after a palatal root torque of 1° were analyzed for each of the 5 models.
RESULTS: With 1° torque predicted, the maxillary central incisor without auxiliaries showed a tendency of labial tipping, mesial tipping, and intrusion. The rotation center moved occlusally in the power ridge model. The labiolingual inclination variation increased in the semi-ellipsoid attachment model but decreased in the power ridge model. The maxillary central incisor is twisted in the distal direction in the power ridge model. The maxillary central incisor of the horizontal rectangular attachment and the horizontal cylinder attachment model behaved similarly to the control model. Periodontal stresses were concentrated in the cervical and apical areas. The maximum von Mises stresses were 11.6, 12.4, 3.81, 1.14, and 11.0 kPa in the 5 models. The semi-ellipsoid attachment model exhibited a more uniform stress distribution than the other models.
CONCLUSIONS: Semi-ellipsoid attachment performed better efficacy on labiolingual inclination, and power ridge performed better efficacy on root control. However, a distal twist of maxillary incisors could be generated by the power ridge.
摘要：
背景：这项研究旨在通过有限元分析评估在用清晰的矫正器将上颌中切牙扭转1°时，不同的辅助装置对牙齿移动和应力分布的影响。
方法：三维有限元模型，包括上颌牙槽骨,牙周膜,牙列,和清晰的对准器，是建造的。根据上颌中切牙上设计的辅助装置，创建了5个模型：(1)无辅助设备(控制模型)，(2)用电源脊，(3)具有半椭圆体的附件，（4）与水平矩形附件，和(5)与水平气缸附件。对5个模型中的每个模型进行了1°的腭根扭矩后的牙齿移动和牙周膜应力分布分析。
结果：预测扭矩为1°，没有辅助的上颌中切牙显示出唇倾翻的趋势，中等小费，和入侵。旋转中心在动力脊模型中八位移动。在半椭球附着模型中，唇舌倾斜度的变化增加，但在力量脊模型中减少。上颌中切牙在动力脊模型中向远端方向扭曲。水平矩形附件和水平圆柱体附件模型的上颌中切牙的行为与控制模型相似。牙周应力集中在宫颈和根尖区域。在5个模型中，最大vonMises应力分别为11.6、12.4、3.81、1.14和11.0kPa。半椭球附着模型比其他模型表现出更均匀的应力分布。
结论：半椭圆体附着对唇舌倾斜有较好的疗效，动力岭对根系控制效果较好。然而,上颌切牙的远端扭曲可以由动力脊产生。
方法：三维有限元模型，包括上颌牙槽骨,牙周膜,牙列,和清晰的对准器，是建造的。根据上颌中切牙上设计的辅助装置，创建了5个模型：(1)无辅助设备(控制模型)，(2)用电源脊，(3)具有半椭圆体的附件，（4）与水平矩形附件，和(5)与水平气缸附件。对5个模型中的每个模型进行了1°的腭根扭矩后的牙齿移动和牙周膜应力分布分析。
结果：预测扭矩为1°，没有辅助的上颌中切牙显示出唇倾翻的趋势，中等小费，和入侵。旋转中心在动力脊模型中八位移动。在半椭球附着模型中，唇舌倾斜度的变化增加，但在力量脊模型中减少。上颌中切牙在动力脊模型中向远端方向扭曲。水平矩形附件和水平圆柱体附件模型的上颌中切牙的行为与控制模型相似。牙周应力集中在宫颈和根尖区域。在5个模型中，最大vonMises应力分别为11.6、12.4、3.81、1.14和11.0kPa。半椭球附着模型比其他模型表现出更均匀的应力分布。
结论：半椭圆体附着对唇舌倾斜有较好的疗效，动力岭对根系控制效果较好。然而,上颌切牙的远端扭曲可以由动力脊产生。
