Al-Rokhami Remsh Khaled, Sakran Karim Ahmed, Al-Worafi Naseem Ali, Al-Balaa Maher, Algahefi Ahmed, 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.
Sci Rep. 2025 Jul 10;15(1):24896. doi: 10.1038/s41598-025-10210-y.
This study aimed to compare the effects of clear aligners and fixed appliances on root resorption, incisive canal (IC) morphology, and the spatial relationship between the maxillary central incisors (U1) and the IC following incisor retraction in dental/skeletal Class I and II extraction cases. Sixty-six adult patients (132 maxillary central incisors) with comparable baseline characteristics (based on the ABO Discrepancy Index) were retrospectively analyzed. Patients received either clear aligners (n = 33) or fixed appliances (n = 33) following first premolar extraction. Pre- and post-treatment CBCT measurements were recorded at three vertical reference planes (H1, H2, H3: 2 mm, 4 mm, and 6 mm above the labial cementoenamel junction), including IC width, cortical bone width (CBW), U1-IC distance, IC height, and U1 root length/width. Both groups showed reductions in IC width, CBW, and U1-IC distance, with greater changes in the fixed appliance group. U1-IC distance was significantly reduced in the fixed group at H1 (1.79 ± 0.76 mm vs. 1.24 ± 1.04 mm), H2 (1.78 ± 1.08 mm vs. 1.33 ± 0.86 mm), and H3 (1.61 ± 1.35 mm vs. 1.16 ± 0.90 mm) (P < 0.05). Root resorption was also significantly higher in the fixed group (1.81 ± 1.55 mm vs. 0.87 ± 0.77 mm, P < 0.001). Root-IC proximity patterns included 7.6% separation, 63.1% approximation, 15.9% contact, and 13.4% invasion, with contact and invasion more prevalent in the fixed group. Root resorption increased with IC proximity, peaking at 3.65 ± 1.97 mm in invasion cases. Regression analysis identified tooth movement, root length, and inter-root distance as predictors of U1-IC proximity, while root resorption was associated with treatment duration, U1 movement, IC height, and incisor inclination (U1-SN angle).These findings underscore the importance of individualized planning and appliance selection in cases requiring maximum anterior retraction to reduce the risk of root resorption and IC-related complications.
本研究旨在比较在牙性/骨性Ⅰ类和Ⅱ类拔牙病例中，使用透明矫治器和固定矫治器进行切牙内收后，对牙根吸收、切牙管（IC）形态以及上颌中切牙（U1）与IC之间空间关系的影响。对66例具有可比基线特征（基于ABO差异指数）的成年患者（132颗上颌中切牙）进行了回顾性分析。患者在拔除第一前磨牙后，分别接受透明矫治器（n = 33）或固定矫治器（n = 33）治疗。在三个垂直参考平面（H1、H2、H3：唇侧牙骨质釉质界上方2 mm、4 mm和6 mm）记录治疗前和治疗后的CBCT测量值，包括IC宽度、皮质骨宽度（CBW）、U1-IC距离、IC高度以及U1牙根长度/宽度。两组患者的IC宽度、CBW和U1-IC距离均减小，固定矫治器组变化更大。在H1（1.79±0.76 mm对1.24±1.04 mm）、H2（1.78±1.08 mm对1.33±0.86 mm）和H3（1.61±1.35 mm对1.16±0.90 mm）水平，固定矫治器组的U1-IC距离显著减小（P < 0.05）。固定矫治器组的牙根吸收也显著更高（1.81±1.55 mm对0.87±0.77 mm，P < 0.001）。牙根与IC的接近模式包括7.6%分离、63.1%近似、15.9%接触和13.4%侵犯，接触和侵犯在固定矫治器组中更常见。牙根吸收随与IC的接近程度增加而增加，在侵犯病例中峰值为3.65±1.97 mm。回归分析确定牙齿移动、牙根长度和牙根间距离是U1-IC接近程度的预测因素，而牙根吸收与治疗持续时间、U1移动、IC高度和切牙倾斜度（U1-SN角）有关。这些发现强调了在需要最大程度前牙内收的病例中进行个性化规划和矫治器选择的重要性，以降低牙根吸收和IC相关并发症的风险。
