Wolf Thomas G., Paqué Frank, Betz Patrick, Willershausen Brita, Briseño-Marroquín Benjamín
Department of Operative Dentistry, Johannes Gutenberg University Medical Center Mainz, Germany
Division of Preventive Dentistry, Periodontology, and Cariology, University of Zurich, Center of Dental Medicine Zurich, Switzerland
Swiss Dent J. 2017 Jun 18;127(6):513-519. doi: 10.61872/sdj-2017-06-281.
The root canal system morphology of the mandibular second molar was investigated by means of micro-computed tomography (μCT). The root canal configuration (RCC), foramina and accessory canals frequency of 93 mandibular second molars of an Egyptian sample were investigated by μCT scans. The RCC and main foramina number (MFN) are described by means of a four-digit system from coronal to apical. The most frequently observed RCCs in the mesial root were 2-2-1/1 (32.3%), 2-2-2/2 (28.0%), 1-1-1/1 (6.5%) and 2-1-1/1 (6.5%); an additional twelve different RCCs were also found here. In the distal root, the RCC 1-1-1/1 was observed in 81.7%; another ten different RCCs with a frequency of less than 5% were also observed in this root. Anastomoses be-tween the mesiobuccal and mesiolingual canals in the mesial root were witnessed in the coronal (20.5%), middle (19.4%) and apical (10.8%) thirds. Accessory canals were found in the coronal (mesiobuccal 15.0%, mesiolingual 12.9%, distobuccal 1.1%), middle (mesiobuccal 7.5%, mesiolingual 10.8%, distolingual 3.3%) and apical (mesiobuccal 19.3%, mesiolingual 16.2%, distolingual 10.8%, distobuccal 2.2%) thirds. The RCC of mandibular second molars showed a great variety. When compared with the first mandibular molar in a historical control from the same sample, the mandibular second molar presented less morphological diversifications. Yet, the mesial root canalsystem of the mandibular second molar showed more RCC variations, connecting and accessory canals than the distal root.
采用显微计算机断层扫描（μCT）技术对下颌第二磨牙的根管系统形态进行了研究。通过μCT扫描，对埃及样本中93颗下颌第二磨牙的根管形态（RCC）、根尖孔及副根管发生率进行了研究。RCC和主根尖孔数量（MFN）采用从冠部到根尖的四位数系统进行描述。近中根最常见的RCC为2-2-1/1（32.3%）、2-2-2/2（28.0%）、1-1-1/1（6.5%）和2-1-1/1（6.5%）；此外还发现了另外12种不同的RCC。远中根中，RCC 1-1-1/1的发生率为81.7%；该根中还观察到另外10种发生率低于5%的不同RCC。近中根近中颊根管与近中舌根管之间的吻合在冠部（20.5%）、中部（19.4%）和根尖部（10.8%）均有发现。副根管在冠部（近中颊侧15.0%、近中舌侧12.9%、远中颊侧1.1%）、中部（近中颊侧7.5%、近中舌侧10.8%、远中舌侧3.3%）和根尖部（近中颊侧19.3%、近中舌侧16.2%、远中舌侧10.8%、远中颊侧2.2%）均有发现。下颌第二磨牙的RCC表现出很大的多样性。与来自同一样本的历史对照中的下颌第一磨牙相比，下颌第二磨牙的形态多样性较少。然而，下颌第二磨牙的近中根管系统比远中根管表现出更多的RCC变异、连接和副根管。
