RESUMEN
Radiographic imaging is an important criteria in diagnosis, treatment planning, and follow-up of an endodontic treatment. When clinicians encounter with diagnostic difficulties and persistent symptoms, the need for advanced diagnostic aids, especially imaging methods, become imperative and essential. This paper reports a case, in which primary endodontic therapy having failed, the patient had persisting symptoms such as pain, swelling, and draining sinus along with signs and symptoms of maxillary sinusitis. Advanced diagnostic aids such as Cone Beam Computed Tomography was useful in accurate identification of the etiology, which was a fractured mesiobuccal root tip of maxillary molar. This is the first reported case, in which the fractured root tip has migrated to the maxillary sinus, during primary endodontic treatment, through the perforated antral floor causing odontogenic sinusitis. The operating microscope helped in the successful completion of endodontic retreatment along with fractured root fragment retrieval.