Risk Factors in Orthodontry : Root resorption

Although orthodontry is one of the safest possible medical procedures around, it is important for patients to know that no medical procedure is entirely risk free. Orthodontry too, has its risks, and I want to write about them for the edification of patients, and as a resource to be used in case you suspect you are the victim of medical malpractice.

Root resorption

One of the rarer ailments that can affect someone is tooth resorption. Occurring extremely rarely among people without braces, 1-5% of people wearing orthodontic appliances will experience this symptom. Tooth resorption is a shortening of the tooth root by at least 1-2 millimeters (this is around 25% of the tooth root), anything under this is not considered a clinical case. Severe root resorption is considered to be for cases where more than 5 millimeters of the tooth root is lost.
Root resorption can be due to a lack of dentine, or it can be caused by the enamel or cementum disappearing from the surface of the tooth. Root resorption can be lateral or apical, the root can shorten or thin out. Sometimes, the surrounding hard tissue (or alveolar tissue) is reabsorbed by the body, and this can cause the tooth itself to atrophy, thus the root shortens. Let’s take a look at the many possible causes of root resorption.

Causes

Orthodontics works on the principle of causing an inflammation of the soft tissues, and moving the teeth around through appliances anchored to the teeth. Some people are genetically predisposed to shortening tooth roots, and when they experience the inflammation caused by orthodontic appliances, their teeth shorten. Sometimes the appliance itself is the cause of the shortening, if it has been put on incorrectly, or if it is applying too much pressure. Sometimes the tooth will stand in such an angle that the alveolar tissue will not need to exert force, which will lead to atrophy of the alveolar tissue, which will lead to root resorption. Nutrition is also a factor, as teeth drain vitamin D and calcium/magnesium, and without these minerals, teeth may start to shorten. For more information on the specific factors, mechanisms and causes of root resorption, please read here. 

Prevention

Basically, microscopic root resorption is inevitable during orthodontic treatment, indeed, it is how the teeth are realigned, and without this shortening, orthodontic treatments would not work at all. To stop it from getting too severe, one should undergo a dental x-ray every 6-9 months during the time that orthodontic appliances are worn. If the x-ray shows even a minor tooth resorption, or the deformation of the tooth root, then the risk of root resorption further on is high, and the appliance should not be worn.

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