Case report: a large radicular cyst involving the entire maxillary sinus.

Cysts of the maxillary sinus of odontogenic origin have been well-documented in the literature. Most of these lesions involve the apex of the offending tooth and appear as a well-defined periapical radiolucency. Presented here is a case of an unusually large lesion, which involved the entire maxillary sinus and extended into the floor of the nose. The lesion also caused paresthesia on the affected side. The lesion was removed with conservative treatment without any postoperative complications.