Lee Ju-Bin, Seo Min-Seock
Department of Conservative Dentistry, Dental College, Wonkwang University, Iksan, Korea.
Department of Conservative Dentistry, Wonkwang University Daejeon Dental Hospital, 77 Dunsan-Ro, Seo-Gu, Daejeon, 302-120, Republic of Korea.
BMC Oral Health. 2022 Apr 26;22(1):145. doi: 10.1186/s12903-022-02184-4.
This study aimed to evaluate the root canal configurations and the association between mandibular first molars and distolingual root (DLR) and mandibular incisors using cone-beam computed tomography (CBCT).
Mandibular first molars and incisors were evaluated using CBCT images of 150 patients. Mandibular first molars were classified according to the presence or absence of DLR. The curvature of the DLR was evaluated using Schneider's method in buccolingual and mesiodistal orientations. The angle of the mesiolingual-distolingual-distobuccal canal orifices (ML-DL-DB) was evaluated at the pulpal floor level. The mandibular central and lateral incisors were classified as either single canal or two canals. The association between the root canal system of the mandibular first molar and mandibular incisors was evaluated. Data were analyzed using the Chi-square test, Student's t-test, and odds ratios from binary logistic regression. The significance level was set at 5%.
The frequency of mandibular first molars with DLR was 27.0% and that of mandibular incisors with two canals was 25.8%. The curvature of the DLR was 37.1° in the buccolingual orientation and 10.4° in the mesiodistal orientation. The angle of ML-DL-DB was 79.0°. The presence of two canal systems in mandibular incisors was associated with the presence of DLR in the mandibular first molar (left central incisors: p = 0.001, odds ratio = 4.25; left lateral incisors: p < 0.001, odds ratio = 3.8; right central incisors: p = 0.003, odds ratio = 3.86; right lateral incisors: p = 0.001, odds ratio = 3.44) but not with the curvature of the DLR or angle of the ML-DL-DB orifice (p > 0.05).
The mandibular first molar showed a high incidence of separate DLRs. It was confirmed that DLR in the mandibular first molar is highly associated with the presence of two-canal system in the mandibular incisors. This association can aid clinicians in successful endodontic treatments.
本研究旨在使用锥形束计算机断层扫描（CBCT）评估下颌第一磨牙的根管形态以及下颌第一磨牙与远舌根（DLR）和下颌切牙之间的关联。
使用150例患者的CBCT图像评估下颌第一磨牙和切牙。下颌第一磨牙根据有无DLR进行分类。采用施奈德法评估DLR在颊舌向和近远中向的弯曲度。在髓室底水平评估近舌-远舌-远颊根管口（ML-DL-DB）的角度。下颌中切牙和侧切牙分为单根管或双根管。评估下颌第一磨牙和下颌切牙根管系统之间的关联。使用卡方检验、学生t检验和二元逻辑回归的优势比分析数据。显著性水平设定为5%。
有DLR的下颌第一磨牙的发生率为27.0%，有双根管的下颌切牙的发生率为25.8%。DLR在颊舌向的弯曲度为37.1°，在近远中向的弯曲度为10.4°。ML-DL-DB的角度为79.0°。下颌切牙双根管系统的存在与下颌第一磨牙中DLR的存在相关（左中切牙：p = 0.001，优势比 = 4.25；左侧切牙：p < 0.001，优势比 = 3.8；右中切牙：p = 0.003，优势比 = 3.86；右侧切牙：p = 0.001，优势比 = 3.44），但与DLR的弯曲度或ML-DL-DB根管口的角度无关（p > 0.05）。
下颌第一磨牙单独的DLR发生率较高。证实下颌第一磨牙中的DLR与下颌切牙双根管系统的存在高度相关。这种关联有助于临床医生成功进行牙髓治疗。
