Al-Rokhami Remsh Khaled, Li Zhihua, Ashour Sarraj, Elayah Sadam, Yang Bin, Zhao Xin, Liu Jingke, Sakran Karim Ahmed
School and Hospital of Stomatology, Nanchang University, Nanchang, Jiangxi, China; Zhenjiang Stomatological Hospital, Zhenjiang, Jiangsu, China.
School and Hospital of Stomatology, Nanchang University, Nanchang, Jiangxi, China.
J World Fed Orthod. 2025 Jul 2. doi: 10.1016/j.ejwf.2025.05.005.
This study aimed to assess changes in morphology, the relationship between the maxillary central incisor (U1) and the incisive canal (IC) and estimate root resorption following extraction orthodontic treatment with fixed appliances, considering gender, age, and skeletal sagittal and facial classifications.
The sample comprised eighty-four maxillary central incisors from 42 patients treated with maxillary incisors retraction using fixed appliances with first premolars extraction. 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).
Significant differences in IC width, U1 length, and U1 root-IC distance were observed across genders, age groups, and skeletal classifications. Root resorption was greater in females (2.60 ± 1.82 mm vs. 1.25 ± 1.20 mm, P = 0.008), adults (2.53 ± 1.71 mm vs. 1.28 ± 1.45 mm, P = 0.009), Class II subjects (2.30 ± 1.86 mm vs. 1.47 ± 1.22 mm, P = 0.040), and the high angle facial group (3.41 ± 1.49 mm vs. 1.10 ± 1.23 mm vs. 0.90 ± 0.75 mm, P < 0.001). Root-IC proximity increased after treatment, showing a positive correlation with resorption, especially at H2 level for approximation (66.7%) and contact (31%), and at the H1 level for invasion (25%). Multivariate regression identified U1 tooth movement and IC height as key factors in negative U1-IC relationships.
Extraction orthodontic treatment with fixed appliances significantly impacts the U1-IC relationship and contributes to root resorption, with variations across demographic and skeletal groups. These findings underscoring the need for precise treatment planning to reduce risks of root resorption and unfavorable U1-IC proximity.
These findings enhance orthodontic treatment planning by identifying factors influencing root resorption and preserving dental health during anterior teeth retraction.
本研究旨在评估使用固定矫治器进行拔牙正畸治疗后上颌中切牙（U1）的形态变化、U1与切牙管（IC）之间的关系，并估计牙根吸收情况，同时考虑性别、年龄、矢状骨面型和面部垂直骨面型分类。
样本包括42例使用固定矫治器拔除第一前磨牙内收上颌中切牙的患者的84颗上颌中切牙。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6mm）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。
在性别、年龄组和骨面型分类中，IC宽度、U1长度和U1牙根-IC距离存在显著差异。女性（2.60±1.82mm对1.25±1.20mm，P=0.008）、成年人（2.53±1.71mm对1.28±1.45mm，P=0.009）、安氏II类患者（2.30±1.86mm对1.47±1.22mm，P=0.040）以及高角面型组（3.41±1.49mm对1.10±1.23mm对0.90±0.75mm，P<0.001）的牙根吸收更明显。治疗后牙根与IC的接近度增加，与吸收呈正相关，尤其是在H2水平的近似（66.7%）和接触（31%）时，以及在H1水平的侵入（25%）时。多因素回归分析确定U1牙齿移动和IC高度是U1-IC负相关关系的关键因素。
使用固定矫治器进行拔牙正畸治疗对上颌中切牙与切牙管的关系有显著影响，并导致牙根吸收，不同人口统计学和骨面型组存在差异。这些发现强调了精确治疗计划的必要性，以降低牙根吸收和上颌中切牙与切牙管不良接近的风险。
这些发现通过识别影响牙根吸收的因素并在拔除前牙期间维护牙齿健康，增强了正畸治疗计划。
