Kottoor, Jojo A permanent mandibular second molar with seven root canal systems. [electronic resource] - Quintessence international (Berlin, Germany : 1985) May 2014 - 381-3 p. digital Publication Type: Case Reports; Journal Article ISSN: 1936-7163 Standard No.: 10.3290/j.qi.a31537 doi Subjects--Topical Terms: AdultHumansMaleMandibleMolar--abnormalitiesPulpitis--surgeryRoot Canal Therapy--methodsTooth Root--abnormalities