Dr. Greg Jorgensen
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1401 Barbara Loop SE
Rio Rancho, NM 87124

The Jorgensen Orthodontics Blog

Why Does the Orthodontist Need Another X-ray?

Posted by Dr. Jorgensen on November 26th, 2012

Bald PanoYour son just had “X-rays” taken at the dentist last month. Why does the orthodontist need to take another one? In fact, why do orthodontists need X-rays at all?

X-rays, officially called radiographs, are images created when a beam of radiation passes through the body and hits a sensor (or a piece of film in older machines) on the other side. X-rays have the ability to create pictures revealing the differences in the densities of the tissues through which they pass. The “shadows” cast on the digital sensor or film allow doctors to see objects hidden by the skin and bone. The most common X-rays taken by general dentists are called bitewings. In a bitewing, the dentist gets a detailed picture of a small group of teeth that reveals the health of the enamel, inner canals, and roots. Enamel and fillings are dense and appear white in color on the radiograph. The bone around the teeth, the root canals, and decay are less dense and therefore appear darker. Dentists are trained to interpret the light and dark patterns so they can distinguish normal tissues from abnormal ones.

X-rays are essential in orthodontics for many reasons. First, orthodontists are also dentists and, although they are focused on different things, they share the responsibility of identifying pathologies if they are present. These include abscesses, tumors, and other things that are not necessarily directly related to straightening the teeth. Although rare, such pathologies are many times identified for the first time by orthodontists and lives can be saved as patients are referred for treatment.

The second reason orthodontists take X-rays is to help them diagnose and treat orthodontic problems. Orthodontic X-rays focus more on the position and form of the teeth and jaws than on individual teeth like bitewings. Orthodontists are especially interested in missing, extra, impacted, or misplaced teeth, and short, long, or misshaped roots. Problems with the jaws include bones that are too big, too small, asymmetrical (off center), too far apart, too close together, or misshapen. X-rays provide orthodontists with essential information that helps them determine where problems exist and the best way to correct them. The size, shape, and position of the teeth and bone in X-rays dictate if surgery or tooth extraction will be necessary.

Orthodontists also take X-rays during treatment so they can monitor how treatment is progressing. Not all effects of orthodontic treatment are visible to the naked eye. Although very rare, moving teeth in some individuals (about 2%) causes the roots to shorten. Orthodontists must check for this during treatment so they can determine if and how long tooth movement should continue. Sometimes orthodontists observe how the teeth are moving to help them finalize the treatment plan. I prefer not to remove permanent teeth if possible, so in many borderline crowding cases I will begin to align the teeth just to see how the teeth and bone respond. If the progress X-ray reveals that there is not enough bone to accommodate all of the teeth, I can always have some removed along the way.

After treatment, a final X-ray is taken to evaluate the outcome of treatment and make recommendations for other necessary procedures (i.e. wisdom teeth). Ideally then, I take one radiograph at the beginning of treatment, one after about six months, and one after the braces come off. Each of these X-rays exposes a patient to less radiation than they would receive taking a typical airplane flight. All dentists are taught to use the ALARA principle (As Little As Reasonably Achievable) when it comes to radiation. I am careful to take X-rays on my patients only when it is in their best interest, and I assume that my colleagues also do the same. Don’t be afraid to ask your orthodontist the reason for your next X-ray.

NOTE: The author, Dr. Greg Jorgensen, is a board-certified orthodontist who is in the private practice of orthodontics in Rio Rancho, New Mexico (a suburb on the westside of Albuquerque). He was trained at BYU, Washington University in St. Louis, and the University of Iowa in the United States. Dr. Jorgensen’s 25 years of specialty practice and 10,000 finished cases qualify him an expert in two-phase treatment, extraction and non-extraction therapy, functional orthodontics, clear aligners (Invisalign), and multiple bracket systems (including conventional braces, Damon and other self-ligating brackets, Suresmile, and lingual braces). This blog for informational purposes only and is designed to help consumers understand currently accepted orthodontic concepts. It is not a venue for debating alternative treatment theories. Dr. Jorgensen is licensed to diagnose and treat patients only in the state of New Mexico. He cannot diagnose cases described in comments nor can he select treatment plans for readers. Because he has over 25,000 readers each month, it is impossible for him respond to all questions. Please read all of the comments associated with each article as most of the questions he receives each week have been asked and answered previously. The opinions expressed here are protected by copyright laws and can only be used with written permission from the author.

30 comments so far in response to “Why Does the Orthodontist Need Another X-ray?”

  1. Mark Kenneth Braga says:

    I just got my braces today. But I didnt undergo measurements, biting on clay thing nor x-ray. When I got to the clinic the doctor directly put on the braces. Is that okey? Need an answer.

    • I would never place braces on a patient without taking diagnostic models, especially an x-ray. There are too many problems that could be present that can’t be seen visibly in the mouth only.

  2. Linda says:

    Dear Dr. Jorgensen, my daughter is 6 yr 4 mons old. In her recent dental checkup the pediatric dentist ordered panoramic xray to check her teeth growth (no sign of problems was found during exam).Unfortunately no image was generated on the computer the 1st time, so office staff had her take xray again. when I came home I began to worry that my daughter possibly got exposed twice
    to xray because I saw xray machine going around her head both times. I got on the internet and read that the radiation from panoramic xray could be double/triple amount of radiation from bitewing. I am so worried that what kind of risk she has. Is it too much radiation exposure from taking x-ray twice? BTW, pano is the only xray taken on the day. Thanks a lot.

    • No worries. The FDA guidelines suggest no more than FOUR large films like that a year, so your daughter will be just fine.

      • Linda says:

        Thank you so much Dr. Jorgensen! May I have one more question? Considering that both my husband and I had crowding teeth, my daughter may need braces in the future. Can the panoramic xray taken at her dentist be used by orthodontist within a certain number of years? Thank you again.

        • Yes it can. Typically we will need a new one every year as long as there are baby teeth and then one every two years there after. The one exception is when the braces are actually on. We need one about 6 months into treatment to monitor for root resorption

      • Linda says:

        Thank you so much for your time, Dr. Jorgensen! Your answer to my x-ray concern has given me a lot of peace. I wish the x-rays were taken several months apart so that FDA guidelines (no more than 4 large films)will put my mind completely at ease. Thinking of my daughter’s case which is repeated x-rays in such short period of time,I tend to think that it has more intense radiation effect and is less safe than x-rays taken months apart. I may be doing nothing but making myself feel worse. Would you shed some light on this?

        • There is no evidence that I am aware of that spreading out x-rays is any safer than having them close together. In fact, radiation exposure is cumulative over time, so it is believed that it doesn’t matter if you have it all at once or spread it out. There is no “healing time” in between. The x-rays cause mutations when they penetrate the DNA (if they cause anything at all) and it doesn’t matter when it happens. Think of it this way, if there was a sniper on top of a building across the street, would you be any safer if he took two shots at you over a few months or over 5 minutes? The probability is the same.

          • Linda says:

            This information is very helpful and informative. I really appreciate it, Dr. Jorgensen! My daughter visits her dentist every six months, her dentist usually orders bitewing once a year. My daughter had bitewing (2 images for back teeth) in October last year, then had panoramic x-ray during most recent checkup in April (possibly exposed twice as described in my post). It is very likely that the dentist will order bitewing at her next visit about 6 months later. If this comes true I’ll be concerned about taking x-rays every 6 months. Is it too frequently? Should I be concerned? Sorry for having so many questions. Thank you again

          • Kids don’t typically need x-rays more than once per year unless there is a reason. Having said that, the amount you’ve described is still within the “safe range.”

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