Purpose: To assess the prevalence of radiographic signs of maxillary sinus pathology in patients undergoing dental implant treatment and to compare the efficacy of panoramic radiography, computed tomography (CT), and three-dimensional (3D) CT with Implametric software in the diagnosis of sinus pathology. Materials and Methods: Thirty patients were selected at random from those being treatment-planned to receive implant-supported restorations in the maxilla and who had a panoramic radiograph, a conventional CT scan in acetate, and a 3D CT scan in digital format. The radiographic maxillary sinus findings were categorized as: (1) no sign of pathology, (2) mucosal thickening, (3) mucous cyst, or (4) occupation of the entire sinus. Results: Seventeen women and 13 men were included, with a mean age of 50.9 years. There was a 38.3% prevalence of radiographic abnormalities (23.3% mucosal thickenings, 10% mucous cysts, and 5% occupation of the entire sinus). Of the 23 sinuses that displayed radiographic signs of pathology, only 1 (4.3%) was correctly diagnosed by the panoramic radiograph. Conclusions: The most common radiographic maxillary sinus finding was mucosal thickening, followed by mucous cysts and occupation of the whole sinus. Conventional CT can be considered a reliable method for the diagnosis of maxillary sinus pathology. Keywords: antral pseudocyst, maxillary sinus, mucocele, panoramic radiograph, sinus elevation