Odontogenic keratocyst involving the maxillary sinus: report of two cases.

The occurrence of odontogenic keratocysts in the maxilla is relatively rare, and invasion of the maxillary sinus unusual. Such cysts are normally small and unilocular. Two large keratocysts with different clinical features and radiological appearances, which had invaded the sinus, are discussed in the case reports presented here. It is suggested that if clinical signs and symptoms are absent, the radiological appearance on both conventional and panoramic radiography may be misinterpreted.