Chuppani Dastgerdi Aria, Navabi Manizheh, Rakhshan Vahid
Department of Dental Morphology, Dental Branch, Islamic Azad University, Tehran, Iran.
Department of Removable Prosthodontics, Dental Faculty, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
Restor Dent Endod. 2019 Dec 12;45(1):e7. doi: 10.5395/rde.2020.45.e7. eCollection 2020 Feb.
This study was performed to assess the anatomy of mandibular first molars.
In this study, cone-beam computed tomography (CBCT) volumes of 312 bilateral intact first mandibular molars from 156 patients (79 men and 77 women; average age, 35.6 ± 11.2 years) were investigated in terms of the direction of each canal's curvature in the buccolingual and mesiodistal dimensions (direction of the position of the apex in relation to the longitudinal axis of the root), the presence of an isthmus (a narrow, ribbon-shaped communication between 2 root canals) in 3 segments (0-2, 2-4, and 4-6 mm) from the apex), and the presence and number of accessory canals (smaller canals besides the main root canals, connecting the pulp to the periodontium). Data were analyzed statistically (α = 0.05).
Mesiolingual canals were mostly buccally and distally inclined, while mesiobuccal and distolingual canals were mostly distally curved. Isthmuses were more common in younger patients (χ test, < 0.05). The average numbers of accessory canals in the apical, middle, and coronal segments were 9.9 ± 4.2, 6.9 ± 2.9, and 9.3 ± 3.0 canals per segment, respectively (analysis of variance, < 0.001). Age and sex were not associated with the number of accessory canals ( > 0.05).
The complex anatomy of these teeth deserves attention during non-surgical or surgical endodontic treatment. Around the apex, isthmuses might be more prevalent in younger and female individuals.
本研究旨在评估下颌第一磨牙的解剖结构。
本研究中，对156例患者（79名男性和77名女性；平均年龄35.6±11.2岁）的312颗双侧完整下颌第一磨牙的锥形束计算机断层扫描（CBCT）图像进行研究，分析各根管在颊舌向和近远中向的弯曲方向（根尖相对于牙根纵轴的位置方向）、根尖上方3个节段（0 - 2、2 - 4和4 - 6 mm）峡部（两根管之间狭窄的带状连通区）的存在情况，以及副根管（除主根管外连接牙髓和牙周组织的较小根管）的存在情况和数量。数据进行统计学分析（α = 0.05）。
近中舌根管大多向颊侧和远中倾斜，而近中颊根管和远中舌根管大多向远中弯曲。峡部在年轻患者中更常见（χ检验，<0.05）。根尖段、中段和冠段副根管的平均数量分别为每段9.9±4.2、6.9±2.9和9.3±3.0条（方差分析，<0.001）。年龄和性别与副根管数量无关（>0.05）。
在非手术或手术牙髓治疗过程中，这些牙齿复杂的解剖结构值得关注。在根尖周围，峡部可能在年轻个体和女性中更普遍。
