A question I get a lot is “I (or my child) just had x-rays taken at the dentist, why do I also need x-rays taken for orthodontics?”
This is a valid question. In years past there was a lot of concern about the dose of radiation received from x-ray machines. As a result, it put patients and parents on high alert about receiving x-rays. The great news is that with the advent of digital radiography we can now enjoy significantly lower doses of radiation than ever before. One panoramic x-ray (radiograph) taken in our office with our digital x-ray machine emits approximately the same amount of radiation as the amount you would receive by simply existing in the world for a day. Another way of looking at it is, it would emit about 1/4th the amount of radiation you would receive flying from NYC to LA.
Now that you are hopefully feeling some relief about the low dosages of radiation, let’s talk about the why. Why do I also need orthodontic x-rays if I’ve had them taken at my dentist?
Dentists most commonly take what we call bite-wing x-rays. These are critical in examining very specific teeth and the detail of each layer of the tooth to check for cavities. Orthodontists need very different types of x-rays. The two most common types of x-rays taken by an orthodontist are a Panoramic and a Lateral Ceph. A Panoramic x-ray for instance does not give as much detailed information about each tooth, but instead gives the orthodontist a good view of the overall positions of the teeth and their roots in the bone. It also allows the orthodontist to check for missing, extra, or impacted teeth. A Lateral Ceph provides information about jaw position and tooth angulation.
Typically these two x-rays need to be taken before starting orthodontic treatment. They are also often taken about half way through treatment. Finally, it is also important to take these x-rays at the end of treatment to check for root health or wisdom teeth.