ORAL-MAXILLARY SINUS FISTULA (OROANTRAL FISTULA) - CLINICAL-FEATURES AND FINDINGS ON MULTIPLANAR CT

OBJECTIVE. Oroantral fistula, an abnormal communication between the or al cavity and the maxillary sinus, is infrequently diagnosed radiologi cally. The purpose of this study was to describe the CT findings and c linical features of oroantral fistula and to show that dental CT multi planar reformatting programs can be instrumental in diagnosing this co ndition. SUBJECTS AND METHODS. 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 alo ng with the clinical presentations. RESULTS. The most frequent CT find ings were bony discontinuity of the maxillary sinus floor, communicati on 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% opa cification of the ipsilateral maxillary sinus, and in 5 of 8 patients the contralateral sinus appeared completely normal. The fistula size r anged from 13.5 mm(2) to 189 mm(2). CONCLUSION. The appearance of oroa ntral fistula on multiplanar CT imaging is disruption of the bony floo r of the maxillary sinus with soft-tissue opacification of the ipsilat eral sinus. Dental reformatted CT can be useful for evaluating patient s suspected of having oroantral fistula, and this condition may be fou nd incidentally in patients referred for evaluation for osseointegrate d root-form dental implants.