Nikkerdar N, Golshah A, Norouzi M, Falah-Kooshki S
Department of Oral & Maxillofacial Radiology, Faculty of Dentistry, Kermanshah University of Medical sciences, Kermanshah, Postal Code: 6715847141, Iran.
Department of Orthodontics, Faculty of Dentistry, Kermanshah University of Medical sciences, Kermanshah, Postal Code: 6715847141, Iran.
Int J Dent. 2020 Mar 9;2020:9178973. doi: 10.1155/2020/9178973. eCollection 2020.
Retromolar canal (RC) is an anatomic structure, and due to increasing demand for surgical procedure in the retromolar area of the mandible, the identification of the retromolar canal has become an issue of clinical concern. It can innervate the third molar and some of the muscles around the posterior segment of the mandible, complicating surgical procedures in the retromolar area and root canal treatment of third molars. The aim of this study was to evaluate the incidence and anatomical properties of RC in a western Iranian population using cone-beam computed tomography (CBCT) images. . Two hundred bilateral CBCT images were collected and screened in the three spatial planes for the presence of an RC. Anatomical properties and location of the RCs were assessed according to their course and distance from the surrounding structures. The relationship between the presence of RC and age, sex, side, and presence of second and third molars was also evaluated. Independent samples -test, ANOVA, Tukey's post hoc test, paired -test, ANOVA, Tukey's post hoc test, paired.
At least one RC was observed in 22% of the mandibles. Its bilateral incidence was 5.5%. Two major types of canals were detected, namely, type I, following a straight or curved course from the mandibular canal (MC) to the retromolar area (47.3%), and type II, coursing from the retromolar area to the radicular part of the third molar (52.7%). Regarding linear measurements, the mean RC diameter and the mean distance to the MC, second, and third molars were 0.68 ± 0.31, 13.7 ± 2.8, 15.3 ± 3.0, and 7.3 ± 2.3 mm, respectively.
Based on the results of this study, RC was found in 22% of the cases; thus, it should be considered as a normal anatomical variation in the Iranian population rather than a rare finding.
磨牙后管（RC）是一种解剖结构，由于下颌磨牙后区外科手术需求的增加，磨牙后管的识别已成为临床关注的问题。它可支配第三磨牙及下颌后段周围的一些肌肉，使磨牙后区的外科手术及第三磨牙的根管治疗变得复杂。本研究的目的是使用锥形束计算机断层扫描（CBCT）图像评估伊朗西部人群中RC的发生率和解剖特性。收集了200例双侧CBCT图像，并在三个空间平面上筛查是否存在RC。根据其走行和与周围结构的距离评估RC的解剖特性和位置。还评估了RC的存在与年龄、性别、侧别以及第二和第三磨牙的存在之间的关系。独立样本t检验、方差分析、Tukey事后检验、配对t检验、方差分析、Tukey事后检验、配对。
在22%的下颌骨中观察到至少一个RC。其双侧发生率为5.5%。检测到两种主要类型的管，即I型，从下颌管（MC）到磨牙后区呈直线或弯曲走行（47.3%），以及II型，从磨牙后区到第三磨牙的根尖部走行（52.7%）。关于线性测量，RC的平均直径以及到MC、第二和第三磨牙的平均距离分别为0.68±0.31、13.7±2.8、15.3±3.0和7.3±2.3mm。
基于本研究结果，在22%的病例中发现了RC；因此，在伊朗人群中应将其视为一种正常的解剖变异，而非罕见发现。
