report of a rare case: a maxillary first molar with seven canals confirmed with cone-beam computed tomography

introduction: coronal anatomic variations in permanent maxillary molars are unusual; conversely variations involving the number of root canals or number of roots are more common. methods and materials: this case report presents a successful nonsurgical endodontic therapy of left maxillary first molar with three roots and seven root canals. this unusual morphology was diagnosed using a dental operating microscope (dom) and confirmed with the help of cone-beam computed tomography (cbct) images. results: cbct axial images showed that both of the palatal and distobuccal roots had vertucci type ii canal pattern, whereas the mesiobuccal root canal showed a sert and bayirli’s type xv configuration. conclusion: the use of a dom and cbct imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system, and therefore treat it far more efficiently.