An X-Ray is formed by a controlled burst of X-Ray radiation which penetrates oral structures at different levels, depending on varying anatomical densities, before striking the film or sensor.
Teeth appear lighter because less radiation penetrates them to reach the film. Dental caries, infections and other changes in the bone density, and the periodontal ligament, appear darker because X-Rays readily penetrate these less dense structures. Dental Restorations (Fillings and Crowns) may appear lighter or darker, depending on the density of the material.
A Orthopantomogram (OPG) or also known as a Panoramic Film, is a special type of X-Ray that looks at the lower face, teeth, jaw joints and sinuses. This X-Ray is useful to demonstrate the number of teeth as well as their position and growth, and is particularly useful to assess teeth that have not yet surfaced e.g. wisdom teeth.
During the OPG procedure, the arm of the machine will rotate slowly around the patients head but will not come into contact with the patient. The Radiographer will instruct the patient to bite onto a plastic mouthpiece which is attached to the machine, this keeps the top and bottom teeth separated and helps position the mouth properly in the machine.
The procedure is very brief (about 15 minutes or less) and is painless and simple. It is very important to follow all instructions and hold absolutely still once positioned.