The middle mesial canal of mandibular first molars.
McCabe
Paul S
PS
D003786:Dental Pulp Cavity / Q000002:abnormalities*; D006801:Humans; D008334:Mandible / Q000000981:diagnostic imaging; D008963:Molar / Q000002:abnormalities* / Q000000981:diagnostic imaging; D011859:Radiography; D012390:Root Canal Therapy / Q000379:methods*; D014092:Tooth Root / Q000002:abnormalities