Digital O.P.G (Ortho-Pantogram)
Dental panoramic radiography equipment consists of a horizontal rotating arm which holds an X-ray source and a moving film mechanism (carrying a film) arranged at opposed extremities. The patient’s skull sits between the X-ray generator and the film. The X-ray source is collimated toward the film, to give a beam shaped as a vertical blade having a width of 4-7mm when arriving on the film, after crossing the patient’s skull. Also the height of that beam covers the mandibles and the maxilla regions. The arm moves and its movement may be described as a rotation around an instant center which shifts on a dedicated trajectory.
Normally, the person bites on a plastic spatula so that all the teeth, especially the crowns can be viewed individually. The whole orthopantomogram process takes about one minute. The patient’s actual radiation exposure time varies between 8–22 seconds for the machine’s excursion around the skull.