title: Mandibular first molars with three mesial canals.
abstract: Five clinical cases demonstrate the presence of a middle mesial canal in the mandibular first permanent molar. This is not an extra canal but rather the sequelae of instrumenting the isthmus between the mesiobuccal and mesiolingual canals.
authors.affiliation: Endodontic Section, Atlantic Coast Dental Research Clinic, Lake Worth, Florida, USA.
authors.forename: Rory E
authors.initials: RE
authors.lastname: Mortman
authors.forename: Sunghee
authors.initials: S
authors.lastname: Ahn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible; D008963:Molar / Q000033:anatomy & histology*; D009811:Odontometry; D011859:Radiography; D018915:Root Canal Preparation; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging