Osseous metaplasia showing heterotopic ossification in the maxillary sinus.

Radiopacity in the maxillary sinus can be observed in various conditions, such as in the presence of lesions in the maxillary sinus or as a sequela of maxillary sinus surgery. This report describes the case of a 57-year-old female patient who had no previous history of surgical treatment or traumatic injury of the nose or maxillary sinus. Both maxillary sinuses were indistinguishable on panoramic radiography and showed signs of radiopacity. Computed tomography images revealed that the maxillary sinuses were filled with bony tissue and exhibited signs of sinus mucosal thickening. Biopsy results showed fragments of trabecular bone with fibrous tissue.