Dental x-rays use electromagnetic radiation to create detailed images of a patient’s teeth and jawbones. Dentists can examine the images generated by an x-ray to detect abnormalities in the teeth or mouth that require treatment.

There are two major types of x-rays:

• Intraoral x-rays. Performed with the x-ray film inside the mouth, they focus on a small area of the teeth and jaw. They are the more common type of x-ray. Examples include bite wing x-rays and periapical x-rays.
  
  
• Extraoral x-rays. Performed with the film outside the mouth, they provide an overview of the jaw and skull. Examples include panoramic radiographs, tomograms and cephalometric projections.

X-rays are often used to monitor tooth growth and development in children. X-rays can also be used to reveal dental problems in patients of all ages. X-rays can reveal tiny pits of decay in the teeth that may not be evident during a visual examination.

X-rays can also be used to detect decay under existing fillings or other dental restorations, or abnormalities such as cysts, impacted teeth, extra teeth and tumors. Infections, periodontal (gum) disease, and injuries to the teeth or jaw can also be diagnosed with x-rays.

No special preparation is required prior to a dental x-ray. Typically, the patient sits in a dental chair and is covered from the chest to the thighs with a leaded apron. Depending on the nature of the x-ray, a film holder with a small piece of film may be inserted into the patient’s mouth and the patient may be asked to bite down on it. The camera is moved into place, and the dental hygienist, certified dental assistant or dentist leaves the room to take the x-ray. The entire process takes just minutes.

Patients generally have their teeth x-rayed on a regular schedule as determined by their dentist. The patient’s age and history of dental visits and dental problems help dictate how often a person needs x-rays. In some cases, x-rays may not be advisable. For instance, dentists generally err on the side of caution and do not recommend dental x-rays for women who are pregnant.

X-rays use very low doses of radiation to produce images. In high doses, radiation can have devastating health consequences for people. However, experts contend that the radiation dose used in dental x-rays is so low that it does not pose a health risk. Dentists and other dental professionals also take certain precautions, such as having patients wear a lead apron, to increase the safety of the procedure.