When you go to your dentist for an annual checkup, they will usually order X-rays, taken by the dental assistant. Radiation from dental X-rays is low and non-threatening. Let’s take a look at the different types of X-rays and why they are taken in the first place.

Types of X-rays Used to Produce Oral Photos

A dental X-ray allows the dentist to see detailed images of your mouth. Various types of dental X-rays are available, including:

  • Bitewing. This type gives your dentist a way to view crowns in the upper and lower jaw. During each X-ray, you bite down on the film holder while the images is taken.
  • Periapical. This type gives your dentist a view of the entire tooth, including the bone.
  • Occlusal. This type lets your dentist evaluate how the your upper and lower teeth fit together when you close your jaw.
  • Panoramic. This one is a 360-degree view of your entire mouth.
  • Cone beam. This X-ray gives the dentist a three-dimensional view, so she can examine the spacing between your teeth.

Why It Is Done

Dental X-rays help your dentist find tooth decay, bone damage and injuries. Oral photos can identify these problems early, even before any symptoms arise. If you have teeth in the wrong place or that are impacted below the gums, it will show on the X-ray.

In addition, oral photos can show cysts, tumors or abscesses that threaten oral health. Further, X-rays help find you find permanent teeth if your child still has their baby teeth.

Most extensive procedures require recent oral photos. X-rays will be ordered if your dentist has to treat things such as extensive cavities, a root canal, install implants, or remove difficult teeth. The same is true of orthodontic treatment where your teeth do not line up straight..

Source
http://www.mayoclinic.org/tests-procedures/dental-exam/basics/what-you-can-expect/prc-20013677
http://www.webmd.com/oral-health/dental-x-rays#1