New nomenclature for extra canals based on four reported cases of maxillary first molars with six canals.

This clinical article describes 4 different case reports of maxillary first molars with unusual anatomy of 6 root canals and their endodontic management. Treating these additional canals in maxillary first molars might be challenging. Inability to locate and properly treat these extra canals might lead to failures. A thorough knowledge of root canal morphology and the proper use of microscopes increase chances for successful clinical results. Because presence of these extra canals is not unusual and naming these canals still remains elusive, a new nomenclature is suggested for ease of communication. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.