Rawaqa Obada, AlNimri Kazem S, Abu Alhaija Elham S
Division of Orthodontics, Preventive Dentistry Department, Faculty of Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid, Jordan.
College of Dental Medicine, QU Health, Qatar University, P.O. Box: 2713, Doha, Qatar.
BMC Oral Health. 2024 Dec 31;24(1):1579. doi: 10.1186/s12903-024-05322-2.
The collum angle, tooth dimensions, root length, and alveolar bone thickness have a significant impact on orthodontic diagnosis and treatment planning. The boundaries of orthodontic tooth movement are determined by alveolar bone thickness and dimensions while the collum angle determines the appropriate positioning of the root relative to the cortical plate. This study aimed to compare the collum angle, crown dimensions, root length, and alveolar bone thickness of the upper and lower incisors, canines, and premolars in subjects with varying anteroposterior relationships.
Cone Beam Computed Tomography (CBCT) images of 89 patients (178 teeth/tooth type) were included in the study. The patients were divided into 4 subgroups according to the incisor relationship. Group 1: Class I (64/tooth type), Group 2: Class II Div 1 (28/ tooth type), Group 3: Class II Div 2 (28/tooth type), and Group 4: Class III (58/ tooth type). The following variables were measured using Carestream CS 3D imaging software on coronal, sagittal, oblique, and reconstructed panoramic views: collum angle, mesiodistal crown width, crown height and thickness, root length, and alveolar bone thickness.
In Class II Div 2 subjects, the collum angles of the upper central and upper lateral incisors were increased. Class III subjects had an increased root length of the upper first premolars, upper central incisors, and lower first and second premolars compared to other groups. In Class II Div 2 subjects, the mesiodistal crown widths were increased in the lower canines compared to Class I and Class III and in the lower central incisors compared to Class II Div 1 and Class III, the height of the crowns was increased in the upper lateral incisors compared to Class III and Class I and in the upper central incisors compared to Class I and Class II Div 1, the buccolingual thickness of teeth was increased in the upper central incisors compared to Class I, Class II Div 1, and Class III and the alveolar bone thickness was increased compared to other groups.
Class II Div 2 subjects exhibited increased collum angle, large crown width, height, and thickness, and increased alveolar bone thickness. Class III subjects had a longer root length compared to other groups.
牙颈角、牙体尺寸、牙根长度和牙槽骨厚度对正畸诊断和治疗计划有重大影响。正畸牙齿移动的边界由牙槽骨厚度和尺寸决定，而牙颈角决定牙根相对于皮质骨板的合适位置。本研究旨在比较不同前后关系受试者上下切牙、尖牙和前磨牙的牙颈角、冠部尺寸、牙根长度和牙槽骨厚度。
本研究纳入了89例患者（178颗牙齿/牙型）的锥形束计算机断层扫描（CBCT）图像。根据切牙关系将患者分为4个亚组。第1组：I类（64颗/牙型），第2组：II类1分类（28颗/牙型），第3组：II类2分类（28颗/牙型），第4组：III类（58颗/牙型）。使用Carestream CS 3D成像软件在冠状面、矢状面、斜面和重建全景视图上测量以下变量：牙颈角、近远中冠宽度、冠高度和厚度、牙根长度和牙槽骨厚度。
在II类2分类受试者中，上颌中切牙和上颌侧切牙的牙颈角增大。与其他组相比，III类受试者的上颌第一前磨牙、上颌中切牙以及下颌第一和第二前磨牙的牙根长度增加。在II类2分类受试者中，与I类和III类相比，下颌尖牙的近远中冠宽度增加，与II类1分类和III类相比，下颌中切牙的冠宽度增加；与III类和I类相比，上颌侧切牙的冠高度增加，与I类和II类1分类相比，上颌中切牙的冠高度增加；与I类、II类1分类和III类相比，上颌中切牙的颊舌厚度增加，且牙槽骨厚度与其他组相比增加。
II类2分类受试者表现出牙颈角增大、冠宽度、高度和厚度增加以及牙槽骨厚度增加。与其他组相比，III类受试者的牙根长度更长。
