Understanding the morphological and structural variations of the tooth is a primary determining factor in predicting the success of endodontic treatment. The complexity of the root canal system of ‘seemingly simple’ premolar teeth has been underestimated. Two rare cases of aberrant root canal anatomy of maxillary and mandibular premolars are presented and appropriate diagnostic and treatment modifications necessary to achieve success in these complex cases are discussed.

Keywords: Root canal anatomy, Maxillary first premolar, Mandibular second premolar, Three canals