The principle of the intraoral periapical (Fig. 11.1) examination is to acquire a view of the tooth and its surrounding structures. Two exposure techniques may be employed for periapical radiography: the paralleling technique and the bisecting angle technique. The paralleling technique is the most common method. This technique gives less image distortion and reduces excess radiation exposure to the patient. The bisecting technique can be applied for subjects unable to accommodate the positioning of the paralleling technique. Shortcomings to the bisecting technique comprise image distortion and excess radiation due to increased angulations involving the eye and thyroid glands. The paralleling technique is so named because the tooth, receptor, and end of the position-­indicating device are all maintained on parallel planes. The principle is based on the fact that image sharpness is primarily affected by the focal-film distance, object film distance, motion, and the effective size of the focal spot of the X-ray tube. It requires the use of film holding devices to maintain the relatively particular positioning needed. A variety of film holders are available: simple, complex, light, heavy, reusable, disposable, autoclavable, and non-autoclavable. A few of the more common include XCP with localizing rings, Snap-a-ray, and Stabe Bite Blocks. In the bisecting technique, the film touches the teeth at the incisal edge or the lingual-occlusal surface and then the rest of the film is angled depending on the anatomy of the area. The X-ray beam is directed perpendicular to the bisecting line between the angle of the long axis of the tooth and the angle of the film. Supporting the film pack with the patient’s forefinger is not recommended.

Bitewing X-rays (Fig. 11.2) show the size of the pulp chamber. They are a useful adjunct to evaluate periodontal conditions, offer a good view of the septal alveolar crest, and, in addition, permit changes in bone height to be accurately assessed by comparison with adjacent teeth. They do not provide information about the apices of the tooth.

Occlusal radiographs (Fig. 11.3) allow a complementary radiographic examination intended to provide a more extensive view of the maxilla and mandible. They are very useful in determining the buccolingual extension and displacement of fractures of the mandible and maxilla. They also aid in localizing unerupted teeth, retained roots, foreign bodies, and calculi in the submandibular and sublingual salivary glands and ducts.

A panoramic X-ray (Fig. 11.4) shows the dentition and surrounding structures, the facial bones and condyles, and parts of the maxillary sinus and nasal complexes. The panoramic radiography equipment comprises a horizontal rotating arm that holds an X-ray source and a moving film mechanism (carrying a film) arranged at opposed extremities. The subject’s head sits between the X-ray generator and the film. The X-ray source is collimated toward the film, to provide a beam shaped as a vertical blade having a width of 4–7 mm (Hatcher 2010