Concurrency of additional canals in mandibular incisors and second mesiobuccal canal in maxillary first molars: A cone-beam computed tomography investigation.

This study investigated the concurrency of additional canals in mandibular incisors and the second mesiobuccal canal in maxillary first molars among the Chinese population. In total, 8644 cone-beam computed tomography images from 8644 patients with bilateral mandibular incisors and maxillary first molars were examined. The data were analysed using Chi-square test, binary logistic regression analysis and receiver operating characteristic curve. Among the patients with additional canals in mandibular central and lateral incisors, 96.2% and 95.5% of them had second mesiobuccal canal in maxillary first molars, respectively. Additional canals of mandibular incisors and second mesiobuccal canal in maxillary first molars exhibited a concurrent relationship. The prevalence of second mesiobuccal canal in maxillary first molars increased with the number of mandibular incisors with additional canals. Moreover, when there was at least one mandibular incisor with additional canals, the presence of the second mesiobuccal canal in maxillary first molars could be highly expected.