The CAT scan is a relatively recent technique in dentistry, used to get an image of what’s happening deep within your jaws. You may be wondering what a CAT scan tells us that a conventional x-ray picture does not, and whether it is worth the extra expense to get one. And how does a CAT scan compare with a conventional x-ray in terms of radiation exposure?
CAT stands for “computer assisted tomography.” Often it’s just called a CT scan, for “computerized tomography.” The word “tomography” comes from roots meaning “slice” and “write.” Tomographic techniques take repeated two dimensional pictures, similar to repeatedly slicing through an object, and then assembles them with a computer to produce a three dimensional (3-D) image.
The latest type of CT scan used in dentistry is called CBCT, or Cone Beam Computed Tomography. The Cone Beam refers to a spiral beam of x-rays, which is used to create a series of two dimensional images from which a computer creates a 3-D image. Such an image is of great value in assessing problems and planning treatment.
Here are just a few examples of how a CBCT scan can be used. Orthodontists can see skeletal structures and developing teeth that are still inside the jawbone while planning strategies for directing the teeth in order to arrive at a better bite. Oral surgeons can find impacted or missing teeth, see their locations, and view their proximity to nerves and sinuses, assisting them in planning surgeries. These scans are particularly useful for root canal specialists because they show root canals that are less than a millimeter wide and even reveal accessory canals that may not be visible on conventional x-rays. In cases of sleep disorders such as sleep apnea, a CBCT during sleep can be used to view a person’s airway and how it may be blocked by the tongue and other soft tissues in a person’s throat during sleep.
Compared to background radiation, the amount of radiation delivered in dental x-rays is minimal. A CBCT delivers a dose of radiation that is less than a typical full mouth x-ray series but more than a typical two dimensional panoramic radiograph. Generally CBCT scanners deliver lower doses than medical CT scanners.
With one low-dose CBCT scan, we can get an accurate idea of the internal structure of your bones and teeth and how they are situated in relation to each other. Prior to the availability of such images, many of these relationships had to be discovered in the course of a surgery or other treatment. Thus such a scan can aid greatly in the quality of treatment you will receive.
Your implants may be in danger, for example, if you have a teeth grinding or clenching habit. This occurs when a person involuntarily and repeatedly bites down on their teeth when not chewing or speaking. Usually triggered in adults by high stress, teeth grinding can subject both natural teeth and implants to damaging levels of force. Over time this can cause bone loss around an implant and weaken their support. It could also cause a direct break in an implant.
But there are ways to stop or at least reduce the effects of teeth grinding. One effective way is a custom-made bite guard you wear while you sleep. Made of hard plastic, the guard prevents the teeth from making solid contact with each other, reducing the amount of force generated.
A more prominent problem is periodontal (gum) disease, a bacterial infection caused by built-up dental plaque on tooth surfaces. This can trigger inflammation, a normal defensive response that when it persists for an extended period of time can damage tissues and supporting bone. It can also cause a specific form of gum disease related to implants called peri-implantitis, in which the tissues that support an implant become infected and weaken, leading eventually to possible implant failure.
If you have implants, then, you should brush and floss daily to prevent gum disease, as well as see your dentist at least every six months for cleanings and checkups. And if you notice anything like reddened, swollen or bleeding gums, see your dentist immediately. The sooner you undergo treatment, the better the outcome for your implants as well as your overall health.
Dental implants can give you years of great service and can prove to be well worth the cost. But you’ll have to stay on your guard against gum disease and other mouth conditions that could endanger them down the road.