Shandong Provincial Key Laboratory of Oral Biomedicine, Department of Endodontics, School of Stomatology, Shandong University, Jinan, China.
J Appl Oral Sci. 2012 Sep-Oct;20(5):563-7. doi: 10.1590/s1678-77572012000500012.
As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published.
To investigate the position of the distobuccal root canal orifice of the maxillary second molars in a Chinese population using cone-beam computed tomography (CBCT).
In total, 816 maxillary second molars from 408 patients were selected from a Chinese population and scanned using CBCT. The following information was recorded: (1) the number of root canals per tooth, (2) the distance between the mesiobuccal and distobuccal root canal orifice (DM), (3) the distance between the palatal and distobuccal root canal orifice (DP), (4) the angle formed by the mesiobuccal, distobuccal and palatal root canal orifices (∠PDM). DM, DP and ∠PDM of the teeth with three or four root canals were analyzed and evaluated.
In total, 763 (93.51%) of 816 maxillary second molars had three or four root canals. The distance between the mesiobuccal and distobuccal orifice was 0.7 to 4.8 mm. 621 (81.39%) of 763 teeth were distributed within 1.5-3.0 mm. The distance between the palatal and distobuccal orifice ranged from 0.8 mm to 6.7 mm; 585 (76.67%) and were distributed within 3.0-5.0 mm. The angle (∠PDM) ranged from 69.4º to 174.7º in 708 samples (92.80%), the angle ranged from 90º to 140º.
The position of the distobuccal root canal orifice of the maxillary second molars with 3 or 4 root canals in a Chinese population was complex and variable. Clinicians should have a thorough knowledge of the anatomy of the maxillary second molars.
使用锥形束 CT（CBCT）研究中国人上颌第二磨牙远颊根管口的位置。
从中国人中选择了 408 名患者的 816 颗上颌第二磨牙，并使用 CBCT 进行扫描。记录以下信息：（1）每颗牙的根管数，（2）近颊根管口与远颊根管口之间的距离（DM），（3）腭侧与远颊根管口之间的距离（DP），（4）近颊、远颊和腭侧根管口形成的角度（∠PDM）。分析和评估具有 3 或 4 个根管的牙齿的 DM、DP 和 ∠PDM。
共有 816 颗上颌第二磨牙中有 763 颗（93.51%）具有 3 或 4 个根管。近颊根管口与远颊根管口之间的距离为 0.7 至 4.8 毫米。621 颗（81.39%）牙齿分布在 1.5-3.0 毫米之间。腭侧与远颊根管口之间的距离范围为 0.8 毫米至 6.7 毫米；585 颗（76.67%）分布在 3.0-5.0 毫米之间。708 个样本（92.80%）的角度（∠PDM）范围为 69.4°至 174.7°，角度范围为 90°至 140°。
中国人上颌第二磨牙 3 或 4 个根管远颊根管口的位置复杂多变。临床医生应充分了解上颌第二磨牙的解剖结构。
