A survey of panoramic radiographs for evaluation of normal and pathologic findings.

Six thousand seven hundred eighty panoramic radiographs were screened to monitor the incidence of normal and pathologic findings. Three different types of panoramic radiograph were used in this study: Panorex, Orthopantomograph, and Panelipse. Visualization of four different anatomic landmarks was used for a statistical comparison of the diagnostic value of the three films: the temporomandibular joint compartments, the external oblique ridge, the mental foramen, and the mandibular canal. The orthopantomograph was judged to be slightly more reliable in producing radiographs for the visualization of the selected anatomic structures. The most common form of pathosis detected was impacted teeth, seen in 22.3 percent followed by retained roots, which appeared in 12.6 percent of the films. Comparing these survey data with three other major studies suggests that confining the previous radiographic examinations to certain selected groups of people may have distorted the incidence of some pathologic conditions in the population. The panoramic radiograph is still considered a supplement to, not a substitute for, the intraoral radiograph.