Morphologic variations in mandibular premolars: a report of three cases.

Background: Mandibular premolars have earned the reputation for having aberrant anatomy. The occurrence of three canals with three separate (type V, Vertucci) foramina in mandibular premolars is very rare. In this report, three cases are presented involving the root canal treatment of mandibular premolars with three different root and canal configurations. The present report also emphasizes the use of the dental operating microscope to enhance visualization.