Fig. 11From: Root and canal anatomy of mandibular first molars using micro-computed tomography: a systematic reviewNew coding system for evaluating accessory canals. Superscript 2: two rooted tooth; MFM: mandibular first molar; M: mesial; superscript A1: presence of one patent accessory canal at the apical third; D: distal; superscript M2-1-0: presence of loop at the middle third of the canal; superscript D: apical deltaBack to article page