Baxter Steffi, Jablonski Marie, Hülsmann Michael
Department of Preventive Dentistry, Periodontology and Cariology, University of Göttingen.
Private Dental Practice.
J Oral Sci. 2020;62(2):180-183. doi: 10.2334/josnusd.19-0113.
This study aimed to evaluate the prevalence of internal symmetry (the number and morphology of root canals) in the mandibular incisors using cone beam computed tomography (CBCT). A total of 302 CBCT scans involving 1,208 mandibular incisors were evaluated using the Vertucci's classification regarding the number and configuration of root canals. The central mandibular incisors exhibited two root canals in 22.6% of patients and lateral incisors in 24.3% of patients. Most teeth (76.4%) had a type I configuration (a single root canal, 1-1), 21.7% had type II (2-1), 1.1% had type V (1-2), and 0.8% had type IV (2-2). Teeth with a type-III configuration (1-2-1) were not found. In total, 17.5% of patients had a symmetric appearance of the two-canalled central mandibular incisors and 20.5% had a bilateral appearance of the two-canal lateral incisors. Moreover, in 12.3% of the patients, all four incisors showed two root canals. The highest degree of symmetry was found in incisors that had one root canal (central incisors: 217 of 302, lateral incisors: 229 of 302), followed by type 2-1 incisors (central incisors 50, lateral incisors 58). The influence of sex and age on the prevalence of symmetries was not significant. Concluding, the internal anatomy of the mandibular incisors cannot not be sufficiently predicted from the root canal anatomy of the contralateral tooth. Thorough clinical and radiographic inspection of each tooth remains mandatory to address the internal anatomy of the mandibular incisors correctly.
本研究旨在使用锥形束计算机断层扫描（CBCT）评估下颌切牙内部对称性（根管数量和形态）的患病率。使用Vertucci分类法对总共302例涉及1208颗下颌切牙的CBCT扫描进行根管数量和形态评估。下颌中切牙在22.6%的患者中显示有两个根管，侧切牙在24.3%的患者中显示有两个根管。大多数牙齿（76.4%）具有I型形态（单根管，1-1），21.7%具有II型（2-1），1.1%具有V型（1-2），0.8%具有IV型（2-2）。未发现具有III型形态（1-2-1）的牙齿。总体而言，17.5%的患者双侧下颌中切牙呈双根管对称外观，20.5%的患者双侧侧切牙呈双根管外观。此外，在12.3%的患者中，四颗切牙均显示有两个根管。单根管切牙（中切牙：302颗中的217颗，侧切牙：302颗中的229颗）的对称性最高，其次是2-1型切牙（中切牙50颗，侧切牙58颗）。性别和年龄对对称性患病率的影响不显著。结论是，不能根据对侧牙齿的根管解剖结构充分预测下颌切牙的内部解剖结构。对每颗牙齿进行全面的临床和影像学检查对于正确了解下颌切牙的内部解剖结构仍然是必不可少的。
