Sinanoglu Alper, Helvacioglu-Yigit Dilek
Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Kocaeli University, Kocaeli, Turkey.
Department of Endodontics, Faculty of Dentistry, Kocaeli University, Kocaeli, Turkey.
J Endod. 2014 Jul;40(7):917-21. doi: 10.1016/j.joen.2014.03.014. Epub 2014 May 2.
The purpose of this study was to document the characteristics of C-shaped canal systems in permanent mandibular second molars using a combination of orthopantomogram (OPT) and cross-sectional cone-beam computed tomographic (CBCT) imaging.
Two hundred participants (94 men and 106 women, mean age = 35 years) who underwent both routine CBCT and OPT examinations were enrolled. One endodontist and 1 oral radiologist examined the images of 339 mandibular second molars and described the radiographic features of C-shaped canals from OPT images as confirmed by CBCT imaging. Root morphology was classified as nonfused (NFRI-II) or fused (FRI-III) based on OPT images. Cross-sectional root canal configurations (C1-C5) were identified from CBCT imaging at 3 different levels (coronal, middle, and apical). Frequency distributions of root morphology and root canal configurations were compared at each level, and interobserver reliability was tested using the Cohen kappa test.
Of the 339 teeth, 29 (8.6 %) had C-shaped root canal systems. Most of the root canals were NFR type (86%); only 2% had C-shaped root canals (all NFRII). In the FR category, 23 teeth with C-shaped canals were equally distributed between the FRI and FRII subtypes. Interobserver agreement was almost perfect (κ = 0.89 and κ = 0.91; right and left second molars, respectively). Per CBCT imaging, the most common configuration was C3 at all levels; no C5 case was detected.
OPT usage can assist in recognizing and diagnosing C-shaped root canal systems. Radicular fusion or proximity is a characteristic feature of C-shaped canal systems. However, nonfused root appearances should also be considered suspicious.
本研究的目的是结合曲面体层片（OPT）和横断面锥形束计算机断层扫描（CBCT）成像，记录恒牙下颌第二磨牙C形根管系统的特征。
招募了200名同时接受常规CBCT和OPT检查的参与者（94名男性和106名女性，平均年龄=35岁）。一名牙髓病医生和一名口腔放射科医生检查了339颗下颌第二磨牙的图像，并根据CBCT成像确认的OPT图像描述了C形根管的影像学特征。根据OPT图像将牙根形态分为未融合（NFRI-II）或融合（FRI-III）。从CBCT成像在3个不同水平（冠部、中部和根尖部）识别横断面根管形态（C1-C5）。比较每个水平牙根形态和根管形态的频率分布，并使用Cohen卡方检验测试观察者间的可靠性。
在339颗牙齿中，29颗（8.6%）有C形根管系统。大多数根管为NFR型（86%）；只有2%有C形根管（均为NFRII）。在FR类别中，23颗有C形根管的牙齿在FRI和FRII亚型之间均匀分布。观察者间的一致性几乎完美（κ=0.89和κ=0.91；分别为右侧和左侧第二磨牙）。根据CBCT成像，所有水平最常见的形态为C3；未检测到C5病例。
使用OPT有助于识别和诊断C形根管系统。牙根融合或接近是C形根管系统的一个特征。然而，未融合的牙根外观也应被视为可疑。
