The relationship of the main foramen to the anatomic root apex has been the subject of several studies. Although they are anatomically close, they rarely coincide, and their distance can vary according to age or tooth type, ranging from 0.2 to 3.0 mm. The aim of this short communication was to evaluate the distance between the main foramen of independent middle mesial canals (MMCs) and the anatomical mesial root apex of mandibular first molars using the micro-computed tomography. Twenty-five mandibular first molars with MMCs were scanned (resolution of 9.9 µm), and the distance from its main foramen to the anatomical apex was evaluated. Overall, the distance ranged from 0.2 to 2.4 mm; however, in 3 specimens the distance was greater than 3 mm. This report demonstrates that the exit of the main foramen of the MMC varies considerably and could approach a substantial distance from the anatomical apex greater than previously reported in the literature.
Discipline-specific terminology is a central element of the vocabulary used by dentists and scientists in the context of their professional activities and plays a critical role in the understanding of dentistry. A number of controversial terms and non-standardized definitions exist in the field of endodontology. For example, in root and canal anatomy, variations exist in the definitions of root morphology (including apical bifurcation, fusion and dilaceration), pulp chamber anatomy (including the outline of the floor, pulp horns and location of the root canal orifice), apical root canal bifurcations, canal isthmuses, accessory canals and apical foramen. This narrative review provides a critical analysis of a range of controversial terms currently used to describe root and canal anatomy. It also addresses the consequences of using such controversial terms on the accuracy and reliability of research findings and clinical practice.