Comparison of the visibility of the anatomical structures of the facial skeleton in panoramic zonography and linear tomography.

The value of cylindrical panoramic radiography (using one rotational axis), a modification of orthopantomography (using three rotational axes), in radiographic examination of maxillo-facial skeleton was estimated by evaluating the visualization of anatomical structures of the facial skeleton on cylindrical panoramic and linear tomographic radiographs of 51 patients examined with both methods. The radiographs were independently reviewed by four radiologists. The visualization of the lateral wall of the orbit and maxillary sinus, nasal septum, alveolar process and zygomatic corpus was better on cylindrical panoramic radiographs. Linear tomography visualized the media wall of orbit better. In visualizing the frontal sinus, orbital floor, medial wall of maxillary sinus and hard palate there were no significant differences between linear tomography and panoramic zonography.