Fan Zeng, Zhang Qi, Jiang Yujun, Qin Qianyi, Huang Sheng, Guo Jie
Postgraduate Student, Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Shandong, China. Postgraduate Student, Shandong Key Laboratory of Oral Tissue Regeneration, Shandong, China. Postgraduate Student, Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong, China.
Professor, Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Shandong, China. Professor, Shandong Key Laboratory of Oral Tissue Regeneration, Shandong, China. Professor, Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong, China, Shandong, China.
Angle Orthod. 2022 Sep 1;92(5):606-612. doi: 10.2319/112021-854.1. Epub 2022 Jul 18.
To analyze the mandibular retromolar space among normal-divergent adult patients with different sagittal skeletal patterns by cone-beam computed tomography (CBCT).
CBCTs of a total of 120 normal-divergent adult patients were investigated. Patients were categorized into the following three groups according to their ANB angle: skeletal Class I (48 patients), skeletal Class II (36 patients), and skeletal Class III (36 patients). Four different planes parallel to the mandibular occlusal plane were used to measure the retromolar space. The retromolar space was measured by two reference lines and then compared between different sagittal skeletal patterns groups. The incidence of root contact with the inner lingual cortex was compared among the three groups.
The retromolar space of the Class III patients was significantly larger than that of Class I patients and Class II patients. Compared with Class I and Class III patients, Class II patients had a smaller retromolar space and higher incidence of contact with the inner cortex of the mandible.
Class III patients had a larger retromolar space than Class I patients and Class II patients in four different planes. The mandibular retromolar space should be evaluated by CBCT in patients who need mandibular molar distalization.
通过锥形束计算机断层扫描（CBCT）分析不同矢状骨面型的成年开颌患者的下颌第三磨牙后间隙。
共研究了120例成年开颌患者的CBCT。根据ANB角将患者分为以下三组：骨骼Ⅰ类（48例）、骨骼Ⅱ类（36例）和骨骼Ⅲ类（36例）。使用四个与下颌咬合平面平行的不同平面来测量第三磨牙后间隙。通过两条参考线测量第三磨牙后间隙，然后在不同矢状骨面型组之间进行比较。比较三组中牙根与下颌舌侧皮质内接触的发生率。
Ⅲ类患者的第三磨牙后间隙明显大于Ⅰ类患者和Ⅱ类患者。与Ⅰ类和Ⅲ类患者相比，Ⅱ类患者的第三磨牙后间隙较小，且与下颌内皮质接触的发生率较高。
在四个不同平面上，Ⅲ类患者的第三磨牙后间隙比Ⅰ类患者和Ⅱ类患者大。对于需要下颌磨牙远移的患者，应通过CBCT评估下颌第三磨牙后间隙。
