Abstract
Introduction: An important issue in treatment planning and endodontic treatment is to deal with
sophisticated internal dental morphology. Deviations from normal anatomy in maxillary molars
are usually related to the number of canals in mesiobuccal root. Although unusual anatomy is not
uncommon in maxillary molars, the occurrence of 3 separate canals with distinct orifices and apical
foramina (as we see in this case) is extremely rare. Getting familiar with this unusual anatomy helps
clinicians to treat patients more efficiently with less chance of failure.
Case Presentation: This case report describes a successful endodontic management of an uncommon
variation of the maxillary first molar with a third mesiobuccal canal. The tooth had a deep carious lesion
and the pulp was irreversibly damaged causing pain on the left side of the face. The periodontium was
normal. The tooth received root canal treatment and 400 mg ibuprofen was prescribed every 6 hours
for 2 to 3 days. The patient remained asymptomatic and the 3-month follow-up radiograph revealed
normal periodontium.
Conclusions: Inability to identify and treat additional canals that are very common in the MB root of
maxillary first molar could lead to treatment failure.