Department of Operative Dentistry, Johannes Gutenberg University Medical Center, Mainz, Germany.
Division of Endodontology, Department of Preventive Dentistry, Periodontology and Cariology, University of Zürich, Zürich, Switzerland.
Int J Oral Sci. 2017 Mar;9(1):33-37. doi: 10.1038/ijos.2016.53. Epub 2017 Jan 20.
The aim of this study was to investigate the root canal configuration, accessory canals and number of main foramina of 123 maxillary second molars by means of micro-computed tomography. The teeth were scanned and reproduced with 3D software imaging. The root canal configuration and number of main foramina were evaluated by means of a four-digit system. The morphological complexity of human maxillary second molars is depicted by the number of accessory and connecting canals. The most frequently observed root canal configurations in the mesiobuccal root were 2-2-2/2 (19.5%), 2-2-1/1 (14.6%) and 2-1-1/1 (13.0%). A 1-1-1/1 configuration was observed in 93.5% and in 96.7% in the distobuccal and palatal roots, respectively. The MB1 root canal had one accessory canal (18.7%), and 8.9% of the MB2 root canal had one or two accessory canals. The distobuccal (11.3%) and palatal (14.6%) root canals had at least one accessory canal, and connecting canals were observed in 16.3% of mesiobuccal roots. The MB1, MB2, distobuccal and palatal root canals had one main foramen in 99.2%, 43.1%, 98.4% and 99.2% of samples, respectively. In the mesiobuccal root, one accessory foramen was detected in 14.6%, two were detected in 7.3%, and three were detected in 5.7%. The distobuccal root showed one or two accessory foramina in 9.1% of samples. The root canal configuration of maxillary second molars is quite heterogeneous; the mesiobuccal root has predominantly two root canal entrances (58.4%, 1 in 41.1%) with one main foramen (54.4%). Two main foramina were observed in 43.0%. Morphological variations, connecting and accessory canals were observed in all apical thirds.
本研究旨在通过 micro-CT 研究 123 颗上颌第二磨牙的根管形态、副根管和主根管数。通过 3D 软件成像对牙齿进行扫描和复制。使用四位数字系统评估根管形态和主根管数。通过副根管和连接根管的数量来描绘人类上颌第二磨牙的形态复杂性。近中颊根最常见的根管形态为 2-2-2/2（19.5%）、2-2-1/1（14.6%）和 2-1-1/1（13.0%）。在远中颊根和腭根中，分别观察到 93.5%和 96.7%的 1-1-1/1 形态。MB1 根管有一个副根管（18.7%），8.9%的 MB2 根管有一个或两个副根管。远中颊根（11.3%）和腭根（14.6%）至少有一个副根管，在 16.3%的近中颊根中观察到连接根管。MB1、MB2、远中颊根和腭根的主根管分别在 99.2%、43.1%、98.4%和 99.2%的样本中只有一个主根管，在近中颊根中，检测到一个副根管的占 14.6%，两个的占 7.3%，三个的占 5.7%。远中颊根的副根管有 9.1%的样本有一个或两个副根管。上颌第二磨牙的根管形态相当复杂；近中颊根主要有两个根管入口（58.4%，41.1%中 1 个），一个主根管（54.4%）。观察到两个主根管的占 43.0%。在根尖三分之一处均观察到形态变异、连接根管和副根管。
