Oral-maxillary sinus fistula (oroantral fistula): clinical features and findings on multiplanar CT.

Abstract

Oroantral fistula, an abnormal communication between the oral cavity and the maxillary sinus, is infrequently diagnosed radiologically. The purpose of this study was to describe the CT findings and clinical features of oroantral fistula and to show that dental CT multiplanar reformatting programs can be instrumental in diagnosing this condition. The study included eight patients with clinically confirmed oroantral fistula or with radiologic evidence of oroantral fistula. Fistula size, degree of alveolar atrophy, nature of maxillary sinus disease, and related dental disease were assessed along with the clinical presentations. The most frequent CT findings were bony discontinuity of the maxillary sinus floor, communication between the oral cavity and the sinus, soft-tissue opacification of the ipsilateral maxillary sinus, focal areas of alveolar atrophy, and associated periodontal disease. In 6 of 8 patients there was 100% opacification of the ipsilateral maxillary sinus, and in 5 of 8 patients the contralateral sinus appeared completely normal. The fistula size ranged from 13.5 mm2 to 189 mm2. The appearance of oroantral fistula on multiplanar CT imaging is disruption of the bony floor of the maxillary sinus with soft-tissue opacification of the ipsilateral sinus. Dental reformatted CT can be useful for evaluating patients suspected of having oroantral fistula, and this condition may be found incidentally in patients referred for evaluation for osseointegrated root-form dental implants.