Maxillary first molar with an unusual morphology: report of a rare case.

Variations in dental anatomy are found in all teeth. Knowledge of these variations, particularly concerning the location and treatment of all canals, is very important for the success of endodontic therapy, because the inability to find and properly treat the root canals may cause failures. Variations in canal morphology, such as extra canals, apical ramifications, apical deltas, or lateral canals, are commonly encountered, and their incidence and significance have been well documented. However, the clinician should also be aware of the possibility of the existence of fewer root and/or canal numbers. The goal of this clinical article is to describe root canal treatment in a maxillary first molar with the unusual morphology of a single root and a single canal.