Wisdom tooth complications - Gum disease (periodontitis). -

Why 3rd molars can be at risk for periodontal disease. | Damage caused to adjacent molars. | Treatment vs. tooth extraction. | Research findings - Correlations and incidence rates.

Wisdom teeth can be difficult to clean. And in those cases where they are, they are at greater risk of developing periodontal problems (gum disease).

As we discuss below, this is an important issue because the gum health of your 3rd molars doesn't just affect them alone but possibly other teeth in your mouth as well. And for this reason, the removal of your wisdom teeth may be a needed preventive measure.

1) Why can wisdom teeth be at increased risk for developing periodontal problems?

Gum disease is caused by oral bacteria. And whenever a tooth cannot be cleansed properly on a regular basis, the bacterial-laden film (dental plaque) that accumulates around it may lead to its formation.

The problem with 3rd molars.

The positioning of some wisdom teeth can be such that it makes them exceptionally difficult to clean.

And when this type of added challenge exists, the teeth involved are left at even greater risk for developing periodontal problems.

Periodontal disease can for around partially erupted wisdom teeth.

The way partially erupted impacted wisdom teeth are buried in the gums can make them especially difficult to clean.

Challenges unique to wisdom teeth.

  • Wisdom tooth impaction - In regard to the potential for developing periodontal disease, the worst case situation for a third molar is one where the tooth is locked in a position where it only partially sticks through the gum line (see illustration).

    When this situation exists, bacteria are able to seep down into the space between the tooth and its gum tissue. The problem is, this area can't be effectively cleansed and therefore the bacterial colony that develops persists undisturbed.

    A wisdom tooth operculum (extra flap of skin).

    The extra flap of gum tissue on this tooth makes it impossible to clean.

  • Gum flaps - Some wisdom teeth have a portion of gum tissue that lies over their chewing surface. This extra tissue is referred to as an operculum.

    As you can see in our picture, this extra flap of tissue makes the tooth essentially impossible to access and thoroughly clean, thus placing it at increased risk for developing gum disease.

  • Difficult access - The general problem that all third molars share is that by nature they occupy a position in the rear of the mouth that is simply difficult to access. That means even non-impacted wisdom teeth can be extremely challenging to keep clean.

When any of the configurations described above exist, the tooth's risk for developing gum problems (either just minor ones [gingivitis] or advanced [periodontitis]) increases.


2) The gum disease around a tooth is not an isolated event.

The conundrum.

For many dental patients the following statements about the need to extract their wisdom teeth may seem a little confusing. It's common that ...

  • A dentist will suggest removing a wisdom tooth so it doesn't develop advanced periodontal disease (periodontitis).
  • But if the tooth isn't extracted and ultimately does develop gum problems, the treatment recommended at that time is the same, pull it.

With either scenario you end up loosing the tooth. So it's easy enough to see why a patient would think why not just wait to see if any problems (tooth looseness, pain, swelling) actually occur?

Periodontal disease around the wisdom tooth impacts the 2nd molar.

Gum disease damage can impact both the 2 and 3rd molars.

The 2nd molar may be affected too.

What must be understood is that gum disease isn't necessarily an isolated event. In fact, it usually isn't.

Specifically with a wisdom tooth, that region of gum tissue and bone that surrounds its front side is the exact same tissue and bone that supports the backside of the next tooth forward (the 2nd molar).

So, if damage occurs (advanced gum disease [periodontitis] can cause the destruction of bone tissue), two teeth are actually affected not just one. (See picture.)

Symptoms and outcome.

This includes both teeth having at least a low-grade chronic infection (the gum disease), becoming loose (as more and more bone is lost), and possibly experiencing an acute infection (with accompanying pain and swelling) from time to time.

Most people would sorely miss a second molar. And it would be a shame to damage or lose one of these valuable teeth simply because a wisdom tooth that could not be cleansed properly was not extracted in time.

Other 2nd molar risks.

It's not just gum disease that can damage the second molar in this type of situation. Tooth decay may play a role too.

The bone destruction caused by the periodontal disease can leave a deep void that traps food, plaque and debris. This mixture creates the perfect environment for the formation of tooth decay. If it does, the teeth involved may be damaged beyond repair.

[Problems with cavities is another one of the "Valid reasons to extract wisdom teeth" issues that we discuss on our pages.]

3) How likely is it that your wisdom tooth will encounter problems with gum disease?

Incidence rates.
  • An evaluation of dental literature (Pogrel 2007) [page references] concluded that the incidence rate of experiencing periodontal complications with a wisdom tooth runs on the order of 1% to 4.5%.
  • This paper also stated that dental patients over the age of 25 years were roughly twice as likely to have an asymptomatic periodontal defect associated with a third molar, as compared to younger patients.

    - The term asymptomatic means "showing no symptoms." So in these cases, a gum problem existed even though the patients were unaware of them.

    - Additionally, this finding simply documents what dentists already know. Older people tend to have more problems with gum disease than younger ones. So, in the case where you are comparatively young and some type of marginal problem already exists with your tooth. Going ahead and having it removed may make preventive sense.


Here are some of the correlations research studies have found.

Periodontal disease has formed between the wisdom tooth and 2nd molar.
  • a) Two large scale studies found that there's a greater probability of finding deep (5mm and greater) periodontal pockets on the distal of 2nd molars (the in-between space identified in our picture) when a visible wisdom tooth is present.

    - The term "visible wisdom tooth" precisely describes the two difficult to clean situations we explain above: 1) An erupted wisdom tooth that's simply hard to access or 2) A partially erupted one, which often involves the situation where almost no below-the-gum-line cleaning can be accomplished at all. In either case, you would expect periodontal problems to exist.

  • b) Other studies have shown that having a visible 3rd molar correlates with the subject's overall level of periodontal disease severity.

    - This finding simply reinforces the fact that gum disease is not a localized event. It tends to affect other areas of the mouth as well.

  • c) Some studies have focused on the types of bacteria living below the gum line around wisdom teeth and the level of pathologic periodontal activity taking place in that person's mouth.

    - The idea associated with these findings is that non-maintainable areas around wisdom teeth can harbor the types of bacteria known to be the causative agents of gum disease. And their presence there tends to impact the health of the mouth as a whole.

(Pogrel 2007)

4) If gum disease is found around wisdom teeth, what should be done?

No one can debate that it can be extremely difficult, if not impossible, for a person to effectively remove dental plaque from around their third molars. But what is debatable is exactly how this difficulty should be managed.

Should the teeth be removed?

Obviously, you'll have to rely on your dentist's judgment. Extraction is one solution but it's not always required.

Non-extraction approaches.

If the bacterial infection (gum disease) surrounding your wisdom teeth can be brought under control and subsequently managed, then there's no real reason to remove them. This might be accomplished via one of the following approaches.

  • More effective oral home care (better brushing and flossing, and possibly incorporating the use of an electric toothbrush into your cleaning routine).
  • More frequent or extensive dental cleanings (scaling and root planing).
  • The use of gum surgery to improve the tooth-gum relationship so adequate cleaning is possible.

Obviously, only your dentist can counsel you on which approach, extraction or alternative, seems to offer the most appropriate solution for your situation.

In the case where the teeth are retained, the level of home care you perform on a daily basis will likely be the deciding factor in what your long-term outcome will be. If you can't commit to keeping that level high, extraction may make the more realistic choice.


Topic Menu ▶  Wisdom Teeth (third molars).


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