Department of Restorative Dental Sciences, College of Dentistry, Majmaah University, Al Majmaah, Saudi Arabia.
Eur Rev Med Pharmacol Sci. 2022 Apr;26(8):2861-2866. doi: 10.26355/eurrev_202204_28616.
For a successful root canal therapy, it is necessary to locate all the canals debride and seal them with an inert filling material. The clinician must be aware of the internal morphology and variations in a permanent tooth. Mandibular first molars are widely studied to identify variations in the anatomy of the pulp space. In this study, the primary objective was to measure the distance between the mesiobuccal (MB) and mesiolingual (ML) canals in patients with and without a middle mesial canal (MMC) using cone-beam computed tomography (CBCT). The secondary objectives were to assess the tapering degree of the mesial root and to measure the dentinal thickness in relation to the danger-zone area in patients with and without an MMC.
A total of 200 CBCT scans were evaluated for the presence of an MMC. Two observers performed the observations, and the results obtained were subject to statistical analyses.
The results revealed the prevalence of MMC was 5%. The average distance between the MB and ML canals was higher when there was an MMC [M(SD) = 3.61 (0.6) vs. 2.69 (0.66)]. However, there were no differences between the groups in the distance to the danger-zone area and the tapering degree of the mesial root. On CBCT images, the MMC was clearly visible 3 mm apical to the level of the cementoenamel junction; beyond 3 mm, the MMC could not be traced.
Based upon the results of this study, the average distance between the MB and ML canals was higher when there was an MMC. A lesser degree of taper would be preferred to prepare the MMC than to prepare the other canals. It is recommended that careful examination of the canal 3 mm apical to the cementoenamel junction should be carried out when attempting to detect an MMC.
要成功进行根管治疗，必须定位所有根管并使用惰性填充材料对其进行清创和密封。临床医生必须了解恒牙的内部形态和变化。下颌第一磨牙被广泛研究以确定牙髓腔解剖结构的变化。在这项研究中，主要目的是使用锥形束 CT（CBCT）测量有和没有中间近中管（MMC）的患者的近中颊（MB）和近中舌（ML）根管之间的距离。次要目标是评估近中根的变细程度，并测量有和没有 MMC 的患者在危险区相关的牙本质厚度。
共评估了 200 个 CBCT 扫描以确定 MMC 的存在。两名观察者进行了观察，并且对获得的结果进行了统计分析。
结果显示 MMC 的患病率为 5%。当存在 MMC 时，MB 和 ML 根管之间的平均距离更高[M（SD）=3.61（0.6）与 2.69（0.66）]。然而，在危险区距离和近中根变细程度方面，两组之间没有差异。在 CBCT 图像上，MMC 在釉牙骨质界下 3mm 处可清晰可见；超过 3mm 时，无法追踪 MMC。
根据这项研究的结果，当存在 MMC 时，MB 和 ML 根管之间的平均距离更高。与预备其他根管相比，预备 MMC 时应更喜欢较小的锥度。建议在试图检测 MMC 时，应仔细检查釉牙骨质界下 3mm 的根管。
