X rays or radiographs are taken routinely in dental clinics. These are required for normal records and also for diagnostic purpose. There is very little danger from the amount of radiation received from routine dental x-rays. The radiation exposure during a dental x-ray examination is so small that the chance it will contribute to any health problems is extremely low. Because of the brief exposure time and the small diameter of the x-ray beam, the skin of the face receives approximately 0.15 roentgens to 0.5roentgens per film.

There are four major types of dental x-ray films : the intra oral films,bite wing films, occlusal films and the panoramic films. For children there is a smaller size of intra oral films available.

For record and diagnostic purpose , the following series of X ray films are used:initial full mouth series, the yearly bite wing series, and the Panoramic x-ray film.

                                       The Full Mouth Series (FMX)




                                                The bitewing series


A bitewing series consists of either 2 or 4 films taken of the back teeth , with the patient biting down so the films contain images of both the top and bottom teeth.



                                           The Panoramic Film (OPG)


The Orthopantogram (OPG) is a large, single x-ray film that shows the entire bony structure of the teeth and face. It takes a much wider area than any intra oral film showing structures outside of their range including the sinuses, and the Temperomandibular Joints. It shows many pathological structures such as bony tumors and cysts, as well as the position of the wisdom teeth. They are quick and easy to take, and cost a little more than a full series of intraoral films. In addition to medical and dental uses, panoramic films are especially good for forensic (legal) purposes in the identification of otherwise unrecognizable bodies after plane crashes or other mishaps.

Panoramic films differ from the others in that they are entirely extraoral, which means that the film remains outside of the mouth while the machine shoots the beam through other structures from the outside.


These films have one major disadvantage. The panoramic film is a lower resolution picture than the intraoral films. This means that the individual structures which appear on them (such as the teeth and bone) are somewhat fuzzy, and structures like caries (tooth decay) and bony trabeculation (the spongelike bone inside the marrow spaces) are imaged without the fine detail seen on intraoral films.