RADIOGRAPHIC IMAGE OF THE HARD PALATE AND NASAL FOSSA FLOOR IN PANORAMIC RADIOGRAPHY

Objective. The aim of this investigation was to report on the radiogra phic interpretation of the hard palate and nasal fossa floor in panora mic radiographs by studying different skulls, x-ray machines, and head positions in relationship to the Frankfort plane before and after ost ectomy Study design. Twenty dry human skulls were radiographed with th ree different panoramic x-ray machines in three different positions. T hree of the skulls were submitted to different ostectomies. Results. M ultiple images of the hard palate and nasal fossa floor were present i n 96.12% of the radiographs. Single images (3.88%) occurred only in th e ''chin up'' position. Conclusions. The lower image represents the na sal fossa floor, especially its lateral and anterior limits. The upper images are double real images mainly formed by the junction of the na sal septum with the nasal fossa floor and possibly by posterior parts of the hard palate and nasal fossa floor. All images overlap in the '' chin up'' position becoming a single image. The most common shape of t he anatomic landmark was wide angle ''W'' (58.33%). Other shapes prese nt in positions ''chin up'' and ''chin down'' indicate patient positio ning errors. The x-ray machines did not influence the results.