Oral Health Prev Dent. 2024 Jul 19;22:301-308. doi: 10.3290/j.ohpd.b5573959.
To assess the prevalence and configuration of bifid (BMC) and trifid (TMC) mandibular canals using computed tomography (CT), describing the anatomical characteristics of the accessory canals, especially of the retromolar type.
CT scans of 123 patients were analysed. BMCs were identified and the patterns of bifurcation were classified, including trifid canals. The width of accessory canals was measured. Retromolar canals were further classified according to their course and morphology, while their position and width were evaluated using linear measurements on CT images.
The majority of patients (53.6%) presented at least one BMC or TMC. 36.2% of mandibular canals were bifid, while 4.5% were trifid. The forward canals (12.6%) and retromolar canals (10.2%) were the most common among BMCs. In relation to the retromolar canals, 60% were vertical and 40% curved, with a mean width of 1.03 ± 0.28mm.
BMCs and TMCs are common 3D radiographic findings, so that they should be considered as anatomical variations, not anomalies. Preoperative CT or CBCT evaluation should aid in identifying these variations and analysing their position and course in surgical planning.
利用计算机断层扫描（CT）评估下颌骨双（BMC）和三叉（TMC）管的发生率和形态，描述副根管的解剖特征，特别是磨牙后类型。
分析了 123 名患者的 CT 扫描。确定 BMC 并对分叉模式进行分类，包括三叉管。测量副根管的宽度。根据其行程和形态进一步对磨牙后管进行分类，同时使用 CT 图像上的线性测量评估其位置和宽度。
大多数患者（53.6%）至少有一个 BMC 或 TMC。36.2%的下颌管是双管，而 4.5%是三叉管。前管（12.6%）和磨牙后管（10.2%）是 BMC 中最常见的。关于磨牙后管，60%为垂直，40%为弯曲，平均宽度为 1.03±0.28mm。
BMC 和 TMC 是常见的 3D 射线照相发现，因此应将其视为解剖变异，而不是异常。术前 CT 或 CBCT 评估有助于识别这些变异，并分析其在手术计划中的位置和行程。
