Structure of the MB2 Canal
The morphology of the mesiobuccal (MB) root of maxillary molars commonly presents 2 main root canals, named MB1 and MB2, and a high incidence of fine anatomical structures including intercanal communications, loops, accessory canals and apical ramifications, resulting in a very complex canal system.
The orifice of the MB2 is usually located either mesial to or in the sub pulpal groove within 3.5 mm palatally and 2 mm mesially from MB1, often hidden under the shelf of the dentine wall or calcifications in a small groove.
In the literature, percentage frequency of MB2 canal in maxillary molars has ranged from 10 to 95%, depending not only on the method used in the study, such as sectioning, dye injection, radiography, scanning electron microscopy, or micro-CT, but also on ethnic and demographic factors related to the studied population, which may include geographic region, age and gender.
