Posts for tag: x-rays
It's difficult to measure how x-ray imaging has transformed dentistry since its use became prominent a half century ago. As equipment and methods standardized, the technology revolutionized the way we diagnose tooth decay and other mouth-related issues.
One of the more useful of these methods is called the bitewing x-ray. The term comes from the shape of the device a patient holds between their teeth with the film attached on the side toward their tongue. We direct the x-ray beam to the outside of the patient's cheek, where it passes through the teeth to expose on the film. Its particular design provides clearer images since the patient's bite helps keep the film still and distortion-free, making it easier to view signs of early tooth decay.
Bitewing x-rays usually consist of four films, two on either side of the mouth, necessary to capture all of the teeth (children with smaller jaws, however, often only require one film per side). How frequently they're conducted depends on a number of factors, including the patient's age: children or young adolescents are usually filmed more frequently than adults, usually every six to twelve months. Frequency also depends on a patient's particular decay risk — the higher the risk the more frequent the x-ray.
Regardless of how often they're performed, a similar application principle applies with bitewing x-rays as with any other radiological method: As Low As Reasonably Achievable (ALARA). With the ALARA principle in other words, we're looking for that sweet spot where we're able to detect the earliest stages of dental disease with the least amount of radiation exposure.
Bitewings fit this principle well: a patient receives only a fraction of the radiation exposure from a four-film bitewing as they do from a daily dose of environmental radiation. Factor in new digital technology that reduces exposure rates and bitewings pose virtually no health risk to patients, especially if conducted in a prudent manner.
The benefits are well worth it. Thanks to bitewing x-rays we may be able to diagnose decay early and stop it before it causes you or your family member extensive tooth damage.
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.