Osteoma in the Maxillary Sinus: Report of Two Cases

Two cases of osteoma arising in the maxillary sinus are reported. Both of the tumors were found incidentally during the evaluation of unrelated diseases. In a 55-year-old female patient, a bone tumor was found on CT, which was taken to rule out paranasal sinusitis. CT showed a pedunculated tumor arising from the inferomedial angle of the maxillary sinus. It was resected intramurally through the canine fossa en bloc. However, a cyst developed under the nasal floor, which was considered to have arisen from the remnant of the maxillary sinus mucosa. The cyst was endoscopically opened to the nasal floor. In a second patient, the tumor was found during the preoperative roentgenological evaluation for dental implantation. The tumor, with its base wide-based, arose from the lower part of the lateral maxillary sinus wall in the vicinity of the alveolar recess. As with the first patient, the tumor was resected through the canine fossa. After this surgery, dental implantation by the all-on-4 method was performed successfully. After dental implantation, however, a thickening of bone, indicative of recurrence, was identified near the entrance of the alveolar ridge on CT. Long-term follow-up is required.