Dentigerous cyst in the maxillary sinus: a rare cause of nasolacrimal obstruction.

The main types of maxillary cysts are antral mucoceles, retention cysts, pseudocysts, dentigerous cysts and keratocysts. Despite the theoretical possibility of maxillary sinus cysts leading to nasolacrimal duct obstruction, only two cases have been reported in the literature so far. The present authors report this rare presentation of a dentigerous cyst with a tooth in the roof of the maxillary sinus, which led to nasolacrimal duct obstruction.