Bilateral ectopic third molar in the maxillary sinuses associated with dentigerous cyst: a case report.

A dentigerous cyst is an epithelial-lined odontogenic cyst formed by an accumulation of fluid between the reduced enamel epithelium and the crown of an unerupted tooth. About 70% of dentigerous cysts occur in the mandible and 30% in the maxilla and the most involved teeth are maxillary canines and maxillary third molars. Dentigerous cysts often displace the related tooth into an ectopic position. In the maxilla, when the cyst expands into the sinus, it usually causes total or partial occupation of the sinus cavity and can extend to the nose. We report a rare case of a 24-year-old woman with bilateral maxillary third molars inside the maxillary sinuses attached to a dentigerous cyst and treated with a minimally invasive endoscopic surgery through the middle meatal meatotomy.