Five-rooted permanent maxillary second molar: CBCT findings of an extremely rare anatomical variant.

Permanent maxillary second molars (MSMs) are the most difficult teeth to treat endodontically because of their complex root canal system. Most MSMs have 3 roots with 3 root canals; however, variations in the root canal configuration and in the number of roots are common. The presence of extra roots in MSMs has been described by several authors, and the reported incidence of 4-rooted MSMs ranges from 0.98% to 5.6%. However, extremely few cases have been reported in the literature in which a living human subject was found to have a 5-rooted MSM. The present report describes the first case of a 5-rooted MSM in a white European subject diagnosed by cone-beam computed tomography.