Mandibular first molar with three distal canals.

A mandibular molar requiring root canal therapy was found with five canals, a mesial root, and two distal roots. The distobuccal root had two separate canals, and the distolingual root had but one. The bizarre aspects of this case are somewhat lessened because of the presence of the second distal root. Practitioners should not become excessively alarmed by the increasing reports of bizarre pulpal anatomy. However, knowledge of their existence may occasionally enable them to treat a case successfully that otherwise might have ended in failure.