Dental X-Rays: Types And Uses

Learn about the different types of X-rays

The Importance of X-rays

X-rays can be uncomfortable and may be your least favorite part of a dental visit, but are a very important part of your dental exam. X-rays can show your dentist not only where there may be cavities, but the condition of your teeth and bone that are hidden below the gum line. Here we will discuss several kinds of x-rays and when you can expect them to be taken.

X-rays and Insurance

X-rays typically fall under the diagnostic/preventive category for insurance benefits. Most insurance plans include diagnostic/preventive benefits in their plans, but may have limitations with either the type of x-ray or the frequency in which they are taken.

As x-rays may only be covered every so often, if you decide to switch dental offices, you will likely need to request that your x-rays are transferred to the new office. This will ensure the new office has all of the x-rays they need without having to re-do them and risk the service not being covered by insurance due to frequency or timing limitations.

Full Mouth and Panoramic X-rays

Did you ever sit in a dental chair with your mouth opened for what seems like an eternity, with an infinite amount of films going in and out of your mouth? This 20-film series is called a full mouth x-ray (FMX) set, which is a combination of 16 single x-rays and four bitewings. The full mouth x-ray series is generally taken at your first visit as a new patient and provides a comprehensive view of your entire oral anatomy. This allows your dentist to design a treatment plan specifically for you or to refer you to a specialist if needed.

Ever stand with an x-ray machine circling your head? This is a panoramic x-ray. A panoramic x-ray scans your entire mouth onto a single large film. It is similar to the full mouth x-ray series, but a panoramic x-ray shows more of your anatomy: your bone level, entire tooth structure, and surrounding areas, including your upper and lower jaws and your sinuses. New panoramic images are usually taken every 3-5 years.

A dentist may order a panoramic or full mouth x-ray depending on the patient's age, concerns, dental history, diagnosis and scope of treatment plan.

Single X-ray

A single x-ray is used to capture the anatomy of an entire tooth beyond what the naked eye can see. This includes the crown (above the gum line), gum line, the tooth root, and the bone surrounding a single tooth. Your dentist may take a single x-ray under these circumstances:

Toothache - to see if there is infection present or a hair line crack that only an x-ray can reveal.
Extraction - to see if there is any remaining tooth structure left after a complicated procedure to ensure all pieces of the tooth have been removed.
Root Canal procedure - to ensure the tooth has been sealed to the root tip.
Crown procedure - to see the fit and position of your new crown.

Occlusal X-ray

An occlusal x-ray is similar to a single x-ray or panoramic x-ray, where only one film is used. However, an occlusal x-ray film is larger than a single x-ray and is typically used in pediatric dentistry to capture an image of the full arch, which means all of the upper teeth (upper arch), or all of the lower teeth (lower arch). When you bring your child to their first visit, your child's dentist may take an occlusal x-ray for each of their arches to determine:

If there are any cavities present on the front teeth
If the adult teeth are present
The position of the adult teeth
If there are extra teeth hanging out behind the baby teeth

Bitewing X-rays

Bitewing x-rays are also known as cavity detecting x-rays (CDT x-ray). These x-rays show cavities in between your teeth, bone density, and bone level which may be impacted by gum disease. Bitewing-x-rays are frequently taken at your cleaning appointment. They come in a series of four films to view all teeth located in the left premolar area, right premolar area, left molar area, and the right molar area.

Reduce Gagging During X-rays

While technology has allowed x-rays to be acquired quickly and digitally, it does not free you from getting the film physically placed in your mouth. Those who experience gagging while having these films placed in their mouths can reduce gagging by closing their eyes and breathing slowly and deeply through the nose.