Tonelli Stéphanie Quadros, Sousa-Neto Manoel Damião, Leoni Graziela Bianchi, Brito-Júnior Manoel, Pereira Rodrigo Dantas, Oliveira Pedro Augusto Xambre de, Nunes Eduardo, Silveira Frank Ferreira
Pontifícia Universidade Católica de Minas Gerais - PUCMG, Department of Dentistry, Belo Horizonte, MG, Brazil.
Universidade de São Paulo - USP, School of Dentistry of Ribeirão Preto, Department of Restorative Dentistry, Ribeirão Preto, SP, Brazil.
Braz Oral Res. 2021 Apr 26;35:e060. doi: 10.1590/1807-3107bor-2021.vol35.0060. eCollection 2021.
This study aimed to describe the morphometric relationship of root canal orifices on the pulp floor in the presence/absence of mesiobuccal second canal (MB2) in the maxillary first molars and other aspects of its internal anatomy. Sixty-two maxillary first molars were scanned by micro-CT. The presence of the MB2 canal was verified. The distance between the center points of the MB1, MB2, distobuccal (DB), and palatal (P) canal orifices on the pulp floor were measured (MB1-MB2, MB1-DB, MB2-DB, MB1-P, and DB-P). The MB1-P to DB-P ratio was calculated. The distances between the anatomic apex and the MB1 and MB2 apical foramina were measured. The length of the band-shaped isthmus was also measured. Student's t-test was applied to verify the association between the presence of an MB2 canal, the interorifice distances, and the ratio of the MB1-P to DB-P distance (α = 5%). The MB2 canal was present in 43 roots (69.35%). Statistics showed significant differences when MB2 was present for the largest MB1-P distance (p < 0.05) and higher values for the MB1-P to DB-P ratio (p < 0.05). A band-shaped isthmus was detected in 25.8% of MB roots. The mean distance from the apical foramen to the isthmus floor ranged from 1.74 for MB1 canals to 1.42 for MB2 canals. Canal orifice distances on the pulp floor may predict the presence of MB2 canals. There was a high incidence of isthmus, accessory canals, and apical delta in the critical apical zone in MB roots of maxillary first molars.
本研究旨在描述上颌第一磨牙中存在/不存在近中颊侧第二根管（MB2）时髓室底根管口的形态计量关系及其内部解剖结构的其他方面。通过显微CT扫描了62颗上颌第一磨牙。确认了MB2根管的存在。测量了髓室底上近中颊侧第一根管（MB1）、近中颊侧第二根管（MB2）、远中颊侧（DB）和腭侧（P）根管口中心点之间的距离（MB1-MB2、MB1-DB、MB2-DB、MB1-P和DB-P）。计算了MB1-P与DB-P的比值。测量了解剖根尖与MB1和MB2根尖孔之间的距离。还测量了带状峡部的长度。应用学生t检验来验证MB2根管的存在、根管口间距离以及MB1-P与DB-P距离比值之间的关联（α = 5%）。43个牙根（69.35%）存在MB2根管。统计学分析显示，当存在MB2根管时，最大的MB1-P距离有显著差异（p < 0.05），MB1-P与DB-P比值更高（p < 0.05）。在25.8%的MB型牙根中检测到带状峡部。从根尖孔到峡部底部的平均距离，MB1根管为1.74，MB2根管为1.42。髓室底的根管口距离可预测MB2根管的存在。上颌第一磨牙MB型牙根关键根尖区峡部、副根管和根尖分歧的发生率较高。
