Xue Kaiyang, Li Qingran, Yang Sihan, Zhao Yuxiang, Li Jiawei, Zhang Chenghao, Liao Wen
Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, CHN.
Cureus. 2024 Aug 19;16(8):e67176. doi: 10.7759/cureus.67176. eCollection 2024 Aug.
This study aimed to assess the alterations in the temporomandibular joint among adult patients undergoing orthodontic treatment involving the extraction of four premolars. A cohort of 44 adults, with a mean age of 24.2 years, underwent orthodontic therapy that included quadruple premolar extractions. Cone-beam computed tomography scans were performed before and after the treatment to evaluate the temporomandibular joints. The three-dimensional assessment focused on the condylar position relative to the cranial base and the articular fossa, the axial condylar rotation, and the joint spaces. Notably, a significant posterior shift of the condyle was detected (P≤0.01), averaging a 0.41mm retraction. The posterior joint space narrowed by 0.32mm post-treatment. Additionally, a medial tilt of 0.62° in the condyle's long axis was observed in the frontal plane. No significant changes were recorded for the other condylar positions, rotations, or joint space dimensions. The findings suggest that orthodontic treatment with four premolar extractions may instigate condylar repositioning and rotation. These insights can inform refinements in treatment protocols.
本研究旨在评估接受四颗前磨牙拔除正畸治疗的成年患者颞下颌关节的变化。44名平均年龄为24.2岁的成年人接受了包括四颗前磨牙拔除的正畸治疗。在治疗前后进行锥形束计算机断层扫描以评估颞下颌关节。三维评估重点关注髁突相对于颅底和关节窝的位置、髁突轴向旋转以及关节间隙。值得注意的是，检测到髁突明显向后移位（P≤0.01），平均后缩0.41mm。治疗后关节后间隙变窄0.32mm。此外，在额平面观察到髁突长轴有0.62°的内侧倾斜。其他髁突位置、旋转或关节间隙尺寸未记录到显著变化。研究结果表明，四颗前磨牙拔除的正畸治疗可能会促使髁突重新定位和旋转。这些见解可为治疗方案的改进提供参考。
