Root Resorption and Resorbing Tooth dental x-ray

Root resorption is a serious issue that can cause permanent damage to your teeth. Oftentimes we see root resorption from braces or some type of traumatic dental injury. Even though it’s not visible when you smile or look in the mirror, your dentist can see the symptoms of tooth root resorption on your X-rays.

Since the symptoms of tooth root resorption aren’t usually evident to the naked eye, it’s important to know what causes them, how they can be avoided, and what to do if it starts.

What Is Root Resorption?

Root resorption is when the physical root structure of your tooth begins to erode or dissolve away. It essentially disintegrates right in front of you, leaving a weaker, shorter, or thinner tooth root behind it.

There are two types of root resorption that a person can get: internal and external.

Internal Root Resorption

Internal root resorption is where the tooth dissolves from the inside out. Normally whenever you look at the X-ray of a tooth root, you see a narrow shadow running down the center. This area is the nerve canal. But in the case of internal tooth resorption, the canal widens and takes over the root structure.

External Root Resorption

External cervical resorption is when the root disintegrates from the outside inward. We usually see external resorption from braces that are too aggressive. On an X-ray, the root of the tooth starts to look shorter and more blunted over time, almost as if your body is eating the tooth root away on its own.

Causes Of Root Resorption

There are four main reasons why we see tooth root resorption. Each one is different, but they typically all result in the same situation. By better understanding the causes and symptoms of tooth root resorption, we can help reduce the risk of tooth loss or major dental emergencies.

1. Dental Trauma

Traumatic injuries can permanently damage the nerve inside of your teeth. It might take years before you start to see symptoms of your tooth beginning to die. A traumatic injury could be anything like a serious automobile accident, getting hit in the mouth during a sport-related activity, or being butted in the head by a squirmy toddler. Although mouthguards can help prevent athletic-related mouth trauma, it’s obviously not practical to wear them 24/7. Accidents still happen. When they do, your dentist will want to monitor the tooth or teeth in question. Symptoms of tooth root resorption can literally take weeks, months, or years to develop after a traumatic dental injury.

2. Braces

Root resorption from braces or other orthodontic treatments is a real thing. Normally, it’s associated with aggressive, rapid tooth movement where the teeth are moved too quickly. Particularly when the tooth movement isn’t controlled properly.[1] The resorption tends to start out at the bottom of the tip of the root, then work its way upward.

When teeth are tipped over extensively and the braces pull or push too hard, it’s thought that some type of an inflammatory response occurs. Orthodontic patients who have a family/genetic history of tooth root resorption or problems with calcium and phosphorus levels tend to be more likely to experience root resorption from braces.[2]

3. Gum Damage

Periodontal infections can cause root resorption. It’s likely due to problems in the periodontal ligament, which is the connective tissue surrounding your entire tooth root, where thousands of microscopic fibers connect the root to the adjacent gum tissue and bone structure. In cases of periodontal disease, the ligaments become infected and detach, causing issues like:[3]

Fortunately, gum disease is easy to screen for and is 100% reversible when it’s caught in the earliest stages of gingivitis. With good home care, you can eliminate gingivitis within two weeks. But once tartar starts to build up, and the gums begin to pull away from your teeth, you need to seek out professional care ASAP.

4. Losing Baby Teeth

When children lose their baby teeth, they experience root resorption. When new adult teeth are ready to come in, the brain signals the body to resort the baby tooth, resulting in the root surface to deteriorate. The baby's tooth roots break down and then the tooth falls out. This process is natural to allow space for new permanent teeth.[4]

5. Nerve Damage

Whenever the pulp (nerve tissue inside of the tooth root) is infected, it can cause internal resorption. The deteriorating nerve tissues don’t repair themselves.

Normally an infected dental nerve presents itself as an abscessed tooth, where there’s visible swelling or drainage near the tip of the tooth root through the gums. But not all nerve damage creates abscesses. Other internal resorption may look like the tooth is thinning out or has a large void forming in the middle of the root or closer to the crown. Only in this case, it’s not a cavity.

Although you might experience some symptoms of tooth root resorption like sensitivity or pain when eating, these types of scenarios are best diagnosed with the help of dental X-rays.

6. Other Reasons

Although far less common, other known causes of tooth root resorption include specific diseases and disorders, like hyperparathyroidism, Paget’s disease, calcinosis, Gaucher’s disease, Turner’s syndrome, and sometimes radiation therapy. Internal tooth bleaching (coronal bleaching) in non-vital teeth may also be to blame.

8 Signs Of Root Resorption

Sometimes resorbing teeth—especially those with external root resorption—never experience any type of noticeable symptoms. In those scenarios, your dentist might choose to wait it out and monitor the area, only removing the tooth once symptoms become painful or severe.

Aggressive areas of tooth root resorption or those involving internal resorption may cause the following symptoms:

1. Infection or Inflammation

Are you experiencing unexplained sore teeth or swollen gums? Especially in one specific area of your mouth? It’s always a good idea for your dentist to take a small X-ray to see what’s going on. Resorption will probably be the last thing on your mind, but it’s not so rare that you don’t want to screen for it.

2. Crooked or Loose teeth

Resorbing teeth lose the tooth and surrounding attachment tissue that holds them in place. As the root shrinks, it creates a weaker foundation. Eventually, the tooth may start to topple over because there simply isn’t enough root to anchor it into the jaw. You could think of it like a fence post that’s only set six inches in the ground, as opposed to a foot and a half.  

3. Pain

Tooth pain ranks high up there with earaches and sometimes even kidney stones. It can be excruciating. When the nerve of a tooth begins to die or is infected, it can sometimes trigger seriously painful sensations in the tooth. But it’s worth noting that not all resorbing or abscessed teeth will hurt, so never let pain be a determining factor as to whether you’re going to seek out care.

4. Chips And Fractures In The Tooth

Resorbing teeth are weak teeth. As the tooth structure dissolves and thins out, it weakens the overall integrity of the tooth as a whole. Without realizing it, you could bite down on normal food, and the tooth will break apart. These teeth tend to chip and fracture more easily because of the density loss deep inside of the tooth anatomy.

5. Holes In The Tooth

Serious resorption will eventually dissolve so much tooth enamel that it creates a hole in your tooth, similar to a cavity. Your dentist can usually see a large void inside of your tooth on the X-ray, even when no visible signs of decay exist.

6. Recession At The Tooth Roots

External tooth root resorption closer to the gumlines destroys the attachment between the root and the periodontal ligaments around it. As those ligaments detach, it causes the gum tissues to pull away from the tooth. Either “pockets” are created, or the tooth roots become exposed as the gums physically recede.

7. Tooth Loss

Whenever a tooth root resorbs so severely, the little structure that’s left is not enough to support the visible portion that protrudes above the gum tissues. As you continue to bite or chew on those teeth, the weakening tooth root will only grow weaker. Gradually, the surrounding attachment tissues will become too strained to withstand all of the forces that come with chewing on those teeth. Either the tooth will fall out on its own, or your dentist will have to extract it due to the worsening condition.

8. Tooth Discoloration And Weakness

Whenever a tooth experiences nerve death from trauma or internal resorption, it typically becomes discolored. These teeth may take on a brown or bluish appearance compared to their neighbors because of the changes going on inside of them, just below the thinning layer of enamel.

Root Resorption Treatment 

The type of treatment you need for root resorption will depend on whether it’s internal or external and how severe it is. Earlier treatment limits how extensive resorption becomes, so early screening is essential.

Internal root resorption may need to be treated with non-surgical endodontic therapy (root canal treatments.) During a root canal, your dentist removes the nerve tissues, cleans and medicates the nerve chamber, then seals it off to prevent recurring infection. But a root canal treatment option only works if the tooth root isn’t perforated.

When root resorption is extremely small, your dentist might take a “watch and wait” approach. Even some endodontic specialists recommend monitoring smaller areas in some cases.

In the instance of teeth that are resorbing because of aggressive orthodontic movement, your dentist may actually need to splint them in place to avoid total tooth loss after all of the orthodontic appliances have been removed.

Root resorption that is up higher on the tooth is more difficult to treat. In many scenarios, tooth extraction is one of the only treatment options available.

When to See Your Dentist

If you’re experiencing unexplained tooth mobility or symptoms of tooth root resorption, schedule an exam and X-rays with your dentist. Resorption isn’t the only possible cause of tooth mobility, as cysts or tumors can also be to blame. The earlier you seek out care with your dentist, the better chances you have of saving your smile.

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