Al-Rokhami Remsh Khaled, Sakran Karim Ahmed, Abdulghani Ehab A, Al-Balaa Maher, Al-Mohana Rana, Li Zhihua
Department of Orthodontics, The Affiliated Stomatological Hospital of Jiangxi Medical College, Nanchang University, No. 49 Fuzhou Road, Nanchang, Jiangxi, China.
Zhenjiang Stomatological Hospital, Zhenjiang, Jiangsu, China.
Odontology. 2025 May 29. doi: 10.1007/s10266-025-01115-3.
This study aims to assess morphological changes, the spatial relationship between the maxillary central incisor (U1) and the incisive canal (IC), and root resorption in non-extraction cases treated with either clear aligners or fixed appliances using 3D-CBCT. Two hundred eight maxillary central incisors from 104 patients underwent maxillary incisors retraction without extraction using clear aligners (n = 60) or fixed appliances (n = 44). Measurements, including IC width, root-IC distance, cortical bone width, IC height, and root resorption, were taken before (T1) and after (T2) treatment at specified heights (H1, H2, and H3; 2, 4, and 6 mm above the labial cementoenamel junction of U1). IC width increased with aligners but decreased with fixed appliances, particularly at H1. IC cortical bone width decreased at various levels, with more pronounced reductions at H1 and H3 in the fixed group. The U1 root-IC distance also decreased significantly in both groups, especially in the fixed group at H1 (0.73 ± 0.86 mm vs 0.40 ± 58 mm, P = 0.042), H2 (0.88 ± 0.94 mm vs 0.47 ± 0.78 mm, P = 0.024), and H3 (0.73 ± 0.92 mm vs 0.30 ± 0.98 mm, P = 0.008). Root-IC proximity patterns varied notably, with higher separation rates in the aligner group and greater approximation, contact, and invasion rates in the fixed group. Root resorption was more significant in the fixed group than in the aligner group (1.01 ± 0.74 mm vs 0.32 ± 0.56 mm, P < 0.001). Factors such as treatment duration, U1 movement, and U1-IC distance were identified as primary predictors of root-IC proximity changes. These results highlight the need for careful treatment planning to preserve root health and prevent IC-related risks. Clear aligners may be preferable in non-extraction cases, particularly when the upper incisor is near the IC or requires more retraction, as they could reduce root resorption while maintaining IC dimensions better than fixed appliances.
本研究旨在利用三维锥形束计算机断层扫描（3D-CBCT）评估使用透明矫治器或固定矫治器治疗的非拔牙病例中上颌中切牙（U1）与切牙管（IC）之间的形态变化、空间关系以及牙根吸收情况。104例患者的208颗上颌中切牙接受了非拔牙上颌中切牙内收治疗，其中使用透明矫治器的有60例，使用固定矫治器的有44例。在治疗前（T1）和治疗后（T2），于特定高度（H1、H2和H3；U1唇侧牙骨质釉质界上方2、4和6毫米处）测量包括IC宽度、牙根-IC距离、皮质骨宽度、IC高度和牙根吸收等指标。IC宽度在使用透明矫治器时增加，而在使用固定矫治器时减小，尤其是在H1处。IC皮质骨宽度在不同水平均减小，在固定矫治器组的H1和H3处减小更为明显。两组的U1牙根-IC距离也均显著减小，尤其是在固定矫治器组的H1（0.73±0.86毫米对0.40±0.58毫米，P = 0.042）、H2（0.88±0.94毫米对0.47±0.78毫米，P = 0.024）和H3（0.73±0.92毫米对0.30±0.98毫米，P = 0.008）处。牙根与IC的接近模式差异显著，透明矫治器组的分离率较高，而固定矫治器组的接近、接触和侵入率较高。固定矫治器组的牙根吸收比透明矫治器组更显著（1.01±0.74毫米对0.32±0.56毫米，P < 0.001）。治疗持续时间、U1移动和U1-IC距离等因素被确定为牙根-IC接近度变化的主要预测因素。这些结果凸显了精心制定治疗计划以保护牙根健康和预防与IC相关风险的必要性。在非拔牙病例中，透明矫治器可能更可取，特别是当上颌切牙靠近IC或需要更多内收时，因为它们可以减少牙根吸收，同时比固定矫治器更好地维持IC尺寸。
