Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal.
Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal.
J Endod. 2017 Sep;43(9):1442-1447. doi: 10.1016/j.joen.2017.04.016. Epub 2017 Jul 19.
The aim of this study was to evaluate and compare the C-shaped mandibular second molar prevalence in different regions around the world with the aid of cone-beam computed tomography technology.
Nine field observers from 9 different geographic regions were calibrated. A total of 400 samples were collected in each region. The prevalence of C-shaped anatomy was calculated. The number of roots and the configuration of the C-shaped canals at 3 different axial levels were also evaluated. The z-test was used to analyze the difference between the means of each independent group. Intrarater reliability was also tested.
A total of 3600 teeth from 2735 patients were included in this research; 499 teeth presented C-shaped root canal configuration, representing a global prevalence of 13.9%. China had a prevalence of 44.0%, which was significantly higher than any other region. The C-shape prevalence in women was 16.5%, which was significantly higher than the 10.4% prevalence found in men. No difference between sides (37 or 47) was evident in the global sample.
Cone-beam computed tomography is a valuable tool to evaluate the C-shaped root canal configuration in vivo. In the present study, China presented the highest prevalence of C-shaped mandibular second molars when compared with other regions. Women exhibited a higher prevalence than men.
本研究旨在借助锥形束 CT 技术评估和比较全球不同地区下颌第二磨牙 C 型发生率。
9 个来自 9 个不同地理区域的现场观察者接受了校准。每个区域共采集 400 个样本。计算 C 型解剖结构的发生率。还评估了 3 个不同轴位上 C 型根管的根数和配置。使用 z 检验分析每组独立数据的平均值之间的差异。还测试了组内可靠性。
本研究共纳入 2735 名患者的 3600 颗牙齿；499 颗牙齿呈现 C 型根管形态，全球发生率为 13.9%。中国的发生率为 44.0%，明显高于其他任何地区。女性的 C 型发生率为 16.5%，明显高于男性的 10.4%。全球样本中没有明显的左右侧差异（37 或 47）。
锥形束 CT 是评估活体 C 型根管形态的有价值工具。在本研究中，与其他地区相比，中国的下颌第二磨牙 C 型发生率最高。女性的发生率高于男性。
