Abstract
A case of 33-year-old male with peculiar shaped bone formation in the bilateral maxillary sinuses is presented.
He visited the hospital because of a persistent uncomfortable sensation in the left cheek. As the diffuse shadow and abnormal calcification in the bilateral maxillary sinuses were found in X-ray examination of CT etc., he underwent the exploratory operation to the bilateral maxillary sinuses. In the left maxillary sinus, there was bone tissue like an imperfect septum which divided the sinus into the anterior one and the posterior one, and a confeteo-shaped bone was on it. A cup-like bone tissue was found in the right maxillary sinus. Both of these bone tissues had no continuity to each sinus wall.
The histopathological examination revealed the following; these bone tissues consisted of the spongy bone covered by compact bone layer. The bilateral maxillary sinus mucosa showed striking chronic inflammatory changes. The tiny bone trabeculae in the early stages of bone development were found in the deep layer of the lamina propria in each maxillary sinus mucosa. The fi ndings of histopathology and the discontinuity to the sinus wall, suggested that these bone tissues were developed from the isolated bone fragments which originated inside the maxillary sinus mucosa.