Complicated Root Canal Morphology of Permanent Mandibular Lateral Incisors is Associated with the Presence of a Second Mesiobuccal Canal in Permanent Maxillary First Molars

Many studies have been conducted in order to define the root canal morphology based on age, gender, ethnic and racial characteristics of the population. However, relations within morphological variations of certain groups of teeth have rarely been investigated. The aim of this study was to evaluate the root canal morphology of mandibular lateral incisors and to determine the association between their morphologic characteristics and the presence of a second mesiobuccal canal of maxillary first molars. Cone-beam computed tomography images from a pre-existing base were analyzed for the bilateral presence of both permanent mandibular lateral incisors and permanent maxillary first molars. Root canal morphology was analyzed according to the Vertucci classification. Associations of root canal morphologies between incisors and molars were calculated as probabilities using binary logistic regression analysis. In total, 126 mandibular lateral incisors and 126 maxillary first molars were included. 46% of all mandibular lateral incisors showed complicated root canal morphology and Vertucci type III canal configuration as the most frequent. Second mesiobuccal root canal was present in 62.7%. Root canal morphologies showed high level of bilateral symmetry in both tooth groups. The probability of a subject having complicated root canal morphology in lateral incisors was significantly higher when the second mesiobuccal canal was present. Clinicians should consider all available information on patients’ root canal morphology when planning new endodontic treatment. Root canal morphology of permanent mandibular lateral incisors showed high association with the root canal morphology of permanent maxillary first molars.