抄録
Odontoma is a relatively common disease among odontogenic tumors. Odontoma is classified into compound odontoma and complex odontoma, and is often accidentally detected by X-ray examination for delayed eruption of teeth in the first and second decades of life. We report a case of compound odontoma with a maximum diameter of over 30mm spreading into the maxillary sinus. A 3-year-old boy was referred for detailed examination of a radiopaque lesion in the left maxilla. Painless swelling of the maxillary left deciduous molar region was found at the first visit, and CT examination revealed numerous tooth-like high-density structures within the left maxillary sinus （CT number 2000 to 2680HU）. A diagnosis of compound odontoma was made, and tumor resection was performed under general anesthesia. In a literature review we found 16 cases of Japanese patients with an odontoma having a maximum diameter of over 30mm spreading into the maxillary sinus. Of those, 15 cases were complex odontoma and one case was a compound odontoma （our case）. These findings suggest that the present case is rare because a relatively large compound odontoma spread into the maxillary sinus.
