OPG: Digital-Orthopantomogram

An Orthopantomogram (OPG), also known as an “orthopantogram” or “panorex”, is a panoramic scanning dental X-ray of the upper and lower jaw. It shows a two-dimensional view of a half-circle from ear to ear.

One particular type of digital system uses a Photostimulable Phosphor Plate (aka PSP – Phosphor Plate) in place of the film. After X-ray exposure the plate (sheet) is placed in a special scanner where the latent formed image is retrieved point by point and digitized, using a laser light scanning. The digitized images are stored and displayed on the computer screen. This method is half way between old film based technology and the current direct digital imaging technology. It is similar to the film process because it involves the same image support handling and differs because the chemical development process is replaced by the scanning process. This is not much faster that film processing and the resolution and sensitivity performances are contested. However it has the clear advantage to be able to fit with any pre-existing equipment without any modification because it replaces just the existing film.