Clinical investigation (In Vivo) of endodontically treated maxillary first molars

The mesiobuccal roots of 228 maxillary first molarswere studied during endodontic therapy, and the canal configurations were categorized. One hundred and seventy-six (77.2%) of the mesiobuccal roots were judged as having two canals. It was also determined that 141 (61.8%) of the samples had two foramina. These figures represent an increase in both canals and foramina from what has been previously reported. We, therefore, suggest that more attention should be directed toward searching for and locating the second canal in the mesiobuccal root of maxillary molars, especially in those patients between 20 and 40 yr of age.