A case of maxillary ossifying fibroma grown up to the fist size.

Ossifying fibroma of the jaw is histologically very similar to fibrous dysplasia. This is a case report of ossifying fibroma which was diagnosed as fibrous dysplasia for a long time. A 24-year-old man, who had a large swelling in left maxillary region, visited our clinic. Previously this lesion which he found 9 years ago was diagnosed histologically as fibrous dysplasia and treated four times. The tumor, however, had grown gradually to fist size. It was diagnosed here as ossifying fibroma from both clinical and histological findings. Tumor was excised under general anesthesia and postoperative course was not eventful for 2 years. Tumor was ball-like mass with dimensions of 66×64×72mm and weighed 180mg. It seemed that CT finding was very useful for differential diagnosis between these to lesions.