Canal configuration in the mesiobuccal root of the maxillary first molar: a clinical study

Surgical telescopes, headlamps, and a modified access preparation were used clinically to aid in the search for mesiolingual canals in the mesiobuccal roots of 208 maxillary first molars. In 148 (71.2%) of the mesiobuccal roots two canals were located and treated. Of these, 66 (31.7%) had two separate apical foramina (Weine Type III) and 82 (39.4%) had two canals that joined (Weine Type II). In 60 (28.9%) cases only one canal was located.