Department of Orthodontics, Cranial-Facial Growth and Development Center, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China.
NMPA Key Laboratory for Dental Materials, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, Beijing, China.
Orthod Craniofac Res. 2024 Feb;27(1):55-63. doi: 10.1111/ocr.12684. Epub 2023 Jun 14.
Palatal displacement of maxillary anterior teeth is common in clinical practice. Previous studies have reported that the labial bone around palatally-displaced incisors is thinner than that around normally-placed teeth. Therefore, it is necessary to elucidate alveolar bone changes after alignment to guide orthodontic treatment. In this study, we investigated the alveolar bone changes around palatally-displaced maxillary lateral incisors before and after treatment, and the effects of extraction and age using cone-beam computed tomography.
In this retrospective study, 55 patients with unilateral palatally-displaced maxillary lateral incisors were included. Three-dimensional alveolar bone changes were measured at three levels (25%, 50% and 75% of the root length) using cone-beam computed tomography. Group comparisons were made between displaced and control teeth, extraction and non-extraction groups, and adult and minor groups.
After orthodontic treatment, labiopalatal and palatal alveolar bone widths decreased at all measured levels. Labial alveolar bone width increased significantly at P25, but decreased at P75. Concavity decreased, while tooth-axis angle, tooth length, B-CEJ and P-CEJ increased. Changes in LB and LP at P75, B-CEJ and P-CEJ were statistically significant. After treatment, the tooth-axis angle on the PD side increased by 9.46°. The change in tooth-axis angle on the PD side was significantly smaller, and LB and LP decreased more at P75, in the extraction group.
Compared to the control teeth, alveolar bone thickness and height for the displaced teeth decreased more significantly after treatment. Tooth extraction and age also influenced alveolar bone changes.
上颌前牙腭向错位在临床实践中较为常见。既往研究报道，腭向错位切牙唇侧牙槽骨较正常牙薄。因此，有必要阐明排齐后牙槽骨的变化，以指导正畸治疗。本研究通过锥形束 CT 研究上颌侧切牙腭向错位患者治疗前后的牙槽骨变化及其与拔牙和年龄的关系。
本回顾性研究纳入 55 例单侧上颌侧切牙腭向错位患者。使用锥形束 CT 测量 3 个部位（根长的 25%、50%和 75%）的牙槽骨三维变化。比较错位牙与正常牙、拔牙组与非拔牙组、成人组与未成年组间的差异。
正畸治疗后，唇腭向和腭向牙槽骨宽度在所有测量部位均减小。P25 处唇侧牙槽骨宽度显著增加，而 P75 处减小。牙槽骨凹度减小，牙轴角、牙长、龈缘顶点（B-CEJ）和釉牙骨质界顶点（P-CEJ）增加。P75 处的 LB 和 LP、B-CEJ 和 P-CEJ 变化有统计学意义。治疗后，PD 侧牙轴角增加 9.46°。PD 侧牙轴角变化较小，拔牙组 P75 处的 LB 和 LP 减小更多。
与正常牙相比，治疗后错位牙的牙槽骨厚度和高度减小更明显。拔牙和年龄也影响牙槽骨变化。
