Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, 140 Hanzhong Rd., Nanjing, 210029, People's Republic of China.
Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
Oral Radiol. 2020 Oct;36(4):365-370. doi: 10.1007/s11282-019-00414-0. Epub 2019 Nov 15.
To evaluate the incidence and location of retromolar canal (RMC) in an eastern Chinese population using cone beam computed tomography (CBCT) images.
Six hundred and fifty-seven patients (276 males and 381 females, 19-49 years old) from east China were enrolled. Both right and left sides of the mandible were examined (n = 1314). Two-dimensional (2D) images of various planes in the mandibular ramus region and reconstructed three-dimensional (3D) images were reviewed. The course of the RMC and the location of the retromolar foramina (RMF) were observed.
Retromolar canal (RMC) was observed in 25.9% (170/657) of patients and 15.7% of sides (206/1314). 20.4% patients had unilateral RMC (134/657) and 5.5% had bilaterally RMC (36/657). Most RMC are horizontally curved course (Type B, 45.6%), followed by vertically curved course (Type A, 44.2%). Type C RMC, which run independently from separate foramina in the mandibular ramus, were relatively rare (10.2%). The distance from the middle of the RMF to the distal end of the second molar ranged from 4.56 to 24.01 mm and the mean distance was 11.97 mm.
RMC is not a rare anatomical structure in the eastern Chinese population. CBCT should be applied as a diagnostic tool to provide detailed information involving the retromolar area.
使用锥形束 CT（CBCT）图像评估东方人群中磨牙后管（RMC）的发生率和位置。
纳入来自中国东部的 657 名患者（276 名男性和 381 名女性，19-49 岁）。对下颌支的左右两侧进行检查（n=1314）。检查下颌支区域各种平面的二维（2D）图像和重建的三维（3D）图像。观察 RMC 的走行和磨牙后孔（RMF）的位置。
25.9%（170/657）的患者和 15.7%的侧位（206/1314）观察到磨牙后管（RMC）。20.4%的患者为单侧 RMC（134/657），5.5%的患者为双侧 RMC（36/657）。大多数 RMC 呈水平弯曲走行（B 型，45.6%），其次是垂直弯曲走行（A 型，44.2%）。相对较少的 RMC 呈独立于下颌支上单独孔走行的 C 型（10.2%）。RMF 中点到第二磨牙远中末端的距离为 4.56-24.01mm，平均距离为 11.97mm。
RMC 在东方人群中并非罕见的解剖结构。CBCT 应作为一种诊断工具应用，以提供涉及磨牙后区的详细信息。
