Jung Hwan-Jun, Lee Sam-Sun, Huh Kyung-Hoe, Yi Won-Jin, Heo Min-Suk, Choi Soon-Chul
School of Dentistry, Seoul National University, Seoul, Korea.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010 Jan;109(1):e37-41. doi: 10.1016/j.tripleo.2009.08.024.
To characterize the presentation of C-shaped canals in mandibular molars on dental panoramic radiographs.
The sample consisted of 290 patients who had undergone both panoramic dental radiography and computed tomography (CT). Initially the presence of mandibular molars with C-shaped canals was identified on this sample by the use CT. This was used as a ground radiographic truth. Then 3 investigators independently classified the mandibular molars according to their 6 root morphologies on panoramic dental radiographs. The sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) of characteristic findings on panoramic radiographs were calculated.
A C-shaped canal was identified in 90 (29%) of 311 mandibular molars. The most common morphology of C-shaped canal molars was 2 separate conical roots (52%); trabecular patterns were relatively common between the roots. In contrast, the most common morphology of molars without C-shaped canals was 2 separate roots that were either divergent or parallel (85%).
Panoramic radiography is a good surveying modality to detect C-shaped canals and can be used to determine whether further examination is required before endodontic treatment.
在牙科全景X线片上描述下颌磨牙C形根管的表现。
样本包括290例接受了全景牙科X线摄影和计算机断层扫描（CT）的患者。最初通过CT在该样本中识别出具有C形根管的下颌磨牙。这被用作影像学的金标准。然后3名研究人员根据全景牙科X线片上的6种牙根形态对下颌磨牙进行独立分类。计算全景X线片上特征性表现的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）。
在311颗下颌磨牙中，90颗（29%）发现有C形根管。C形根管磨牙最常见的形态是2个独立的锥形根（52%）；牙根之间的小梁模式相对常见。相比之下，无C形根管磨牙最常见的形态是2个分开的根，呈发散或平行状（85%）。
全景X线摄影是检测C形根管的良好检查方式，可用于确定在根管治疗前是否需要进一步检查。
