Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
J Endod. 2021 Apr;47(4):585-591. doi: 10.1016/j.joen.2021.01.003. Epub 2021 Jan 23.
The aim of this study was to evaluate if the configuration of canal orifices can predict the presence of a second mesiobuccal canal (MB2) in maxillary second molars with fused roots.
Maxillary second molars with fused roots (N = 150) were scanned in a micro-computed tomographic device (pixel size = 9 μm) and evaluated regarding the root fusion type and the incidence of the MB2 canal. The centers of the canal orifices were connected, and the angles formed by the intersection of these lines as well as their distances were measured and statistically compared (1-way analysis of variance). Specimens were then assigned to 2 groups according to the presence (n = 65) or absence (n = 50) of the MB2 canal and compared regarding the angles and interorifice distances using the Welch t test. A binary logistic regression model estimated the association between the interorifice distance, the fusion type, and the presence of the MB2 canal, whereas receiver operating characteristic curve analysis was performed to evaluate the diagnostic abilities of significant variables. The significance level was set at 5%.
The most common fusion types were 1 and 6, and MB2 canal incidence was 47.3%. No statistical difference was observed in the angles or interorifice distances among teeth with different fusion types (P > .05). Distances from the mesiobuccal (MB) to the distobuccal and palatal (P) canal orifices as well as the MB and P angles were significantly higher in the presence of an MB2 canal (P < .05). A binary logistic regression model revealed that MB-distobuccal and MB-P distances were significant in the presence of an MB2 canal (P < .05). Receiver operating characteristic analysis indicated that MB-P distance had acceptable diagnostic accuracy for the prediction of MB2 canal presence. Sensitivity (specificity) calculated from the MB-P distances of 4.0, 4.5, and 5.0 mm were 89.2% (36.5%), 76.9% (58.4%), and 44.4% (71.4%), respectively.
MB-P interorifice distance is a strong predictor of the presence of the MB2 canal in maxillary second molars with fused roots.
本研究旨在评估根管口的形态是否可以预测融合根的上颌第二磨牙中是否存在第二近中颊根管（MB2）。
对 150 颗融合根的上颌第二磨牙进行微计算机断层扫描（像素大小=9μm），并评估根融合类型和 MB2 根管的发生率。根管口的中心连接起来，这些线相交形成的角度以及它们之间的距离进行测量并进行统计学比较（单因素方差分析）。然后根据是否存在（n=65）或不存在（n=50）MB2 根管将标本分为 2 组，并使用 Welch t 检验比较两组之间的角度和根管口之间的距离。二项逻辑回归模型估计根管口之间的距离、融合类型和 MB2 根管存在之间的相关性，而接收者操作特征曲线分析则用于评估有意义变量的诊断能力。显著性水平设定为 5%。
最常见的融合类型为 1 型和 6 型，MB2 根管的发生率为 47.3%。不同融合类型的牙齿之间，根管口之间的角度或距离没有统计学差异（P＞0.05）。存在 MB2 根管时，近颊（MB）至远颊（DB）和腭（P）根管口之间的距离以及 MB 和 P 角度明显更高（P＜0.05）。二项逻辑回归模型显示，存在 MB2 根管时，MB-远颊（DB）和 MB-P 距离是显著的（P＜0.05）。接收者操作特征分析表明，MB-P 距离对预测 MB2 根管的存在具有可接受的诊断准确性。根据 MB-P 距离为 4.0、4.5 和 5.0mm 计算的敏感性（特异性）分别为 89.2%（36.5%）、76.9%（58.4%）和 44.4%（71.4%）。
MB-P 根管口之间的距离是融合根上颌第二磨牙中存在 MB2 根管的有力预测指标。
