Other reasons why wisdom teeth should be removed.
This page outlines how cyst and tumor formation, issues associated with poor tooth alignment or positioning, chronic pain, and potential damage to neighboring teeth can each be a justification for the removal of third molars.
It also explains why the theory that wisdom teeth coming in can cause tooth crowding or shifting doesn't hold water and therefore is not a valid reason to extract them.
After you've finished with this page, you may find our related one titled "Is it always necessary to remove impacted wisdom teeth?" of interest.
Valid reasons to extract third molars -
A) Wisdom teeth that cause pain.
- The most common reason why people seek an evaluation of their wisdom teeth is because they have experienced a painful episode.
- Having pain is the most common third molar symptom. 33% of patients who have symptoms report this as one of them.
Pogrel (2007) [page references]
Sources of 3rd molar pain.
a) The eruption process.
It's possible that the discomfort a person notices is related to the tooth's eruption process. It may be intermittent or persistent. Patients sometimes describe it as feeling a vague sense of pressure.
b) Other causes.
It's more likely that a person's discomfort is due to some other wisdom tooth-related issue. This could include most any of the conditions and situations discussed on both this and our previous page.
- Some of the more likely ones are pain associated with an infection around the tooth, or trauma to the thin layer of skin (gum flap) that lies over it.
- Other issues can involve just the wisdom tooth itself, or possibly the adjacent 2nd molar too. These can include pain as a consequence of tooth decay, gum disease or root resorption.
c) Pressure on adjacent nerves.
In rare cases, an impacted lower wisdom tooth may place pressure on the nearby inferior alveolar nerve (the major nerve of the lower jaw). This may cause intermittent pain, a general sense of pressure or even headaches. (Haq 2002)
d) Pain of unknown origin.
There can be instances where discomfort is felt in the region where an impacted wisdom tooth lies. But due to the absence of obvious pathology, the dentist can't be certain that the tooth itself is the culprit.
If there are no absolute contraindications for removal, these teeth are sometimes extracted, with the patient's understanding that pain relief may not be achieved.
(Sometimes the discomfort stems from the nearby tempromandibular joint (jaw joint) or spasm of its associated muscles. This scenario is especially likely if the person has a habit of clenching or grinding their teeth.)
B) Poorly positioned wisdom teeth.
Some wisdom teeth manage to erupt but nevertheless have a positioning that causes, or has the potential to cause, problems. For example:
Trauma to both flap and cheek tissue in the area of a 3rd molar.
a) Crooked teeth.
Teeth whose final positioning is tilted or angled may poke, scrape, crush (bite) or otherwise irritate adjacent cheek or gum tissue. For the most part, the only solution that exists is to extract the offending tooth.
Chronic tissue trauma may cause hyper-keratinization (like the line of dense tissue that makes up the white streak on the inside of the cheek in our picture).
b) High gums or gum flaps.
Gum tissue that creates a tall collar around a third molar, or lies as a flap over its chewing surface, may constantly be traumatized by hard foods or opposing teeth.
This may cause the tissue to become chronically inflamed (reddened, sore and swollen, like the "flap" tissue in our picture).
In some cases, the excess tissue can be successfully trimmed away. In others, it may tend to grow back over time. (It depends on the tooth to jawbone relationship that exists.) If your dentist determines that the latter is the likely outcome for your situation, then the tooth will need to be extracted.
c) Supererupted third molars.
Wisdom teeth that don't have an opposing tooth to bite against often supererupt (poke through the gum tissue further than normal).
These teeth may cause tissue irritation or trauma. Their abnormal positioning may interfere with jaw movements, or create traps between teeth where food and debris tend to accumulate. Teeth having this problem should be extracted.
d) Teeth that are hard to clean.
Some wisdom teeth occupy a position that makes them very difficult to brush and floss. If so, both they and their neighboring tooth are placed at increased risk for complications with tooth decay and gum disease. And for that reason, they should be removed before problems develop.
C) Cysts and tumors.
While they're not an especially common occurrence, cysts and tumors can develop in the tissues around an impacted wisdom teeth.
They're frequently associated with the developmental tissues that have formed the tooth. And as they grow in size, they may cause damage to surrounding bone, nearby structures such as adjacent teeth or cause a distortion of the jawbone.
If pathology is observed (in early stages, this is frequently via the use of x-ray examination), the associated tooth should be removed and its cyst or tumor evaluated by a pathologist.
Monitoring impacted wisdom teeth.
In cases where a decision has been made not to remove a person's impacted wisdom tooth, it should be evaluated periodically via x-ray examination. Doing so allows the dentist to compare current and previous films, in search of changes that may indicate that a cyst or tumor is forming.
Misdirected eruption can trigger resorption of adjacent teeth.
D) Root resorption of neighboring teeth.
The attempted eruption of a misdirected impacted wisdom tooth can cause damage (root resorption) to a person's 2nd molar. Fortunately, this is an uncommon occurrence.
This event is somewhat similar to what happens with baby teeth. When they fall out, they look as though they don't have a root. That's because as the permanent tooth underneath erupted, its presence caused the baby tooth's root to dissolve away.
In similar fashion, when a misdirected wisdom tooth attempts to erupt, its pressure can cause resorption of the rear root of the 2nd molar. The worst case scenario in this type of situation is one where the offending wisdom tooth and the damaged 2nd molar will both have to be extracted.
Reasons given for removing wisdom teeth that are questionable.
A) Tooth crowding (shifting).
There's a theory that suggests that wisdom teeth, as a part of their normal eruption process, tend to direct pressure to the teeth in front of them. And as a result, they become crooked (crowded, shifted).
Changes in the alignment of lower front teeth, especially, are blamed on this suspected phenomenon.
What has research proven?
A fairly recent publication (Cochrane 2012) performed a review of research studies that had evaluated this issue and concluded that there was no evidence to support the routine removal of 3rd molars as a preventive for lower front tooth crowding.
That's not to say that people don't have teeth that do shift. But rather that research studies haven't been able to attribute the shifting to the eruption process of wisdom teeth (impacted or not).
In fact, some studies have found that people who lack wisdom teeth (were born without tooth buds for 3rd molars) experience this same crowding phenomenon.
Other theories that explain tooth crowding.
Instead of trying to attribute tooth shifting to wisdom teeth, researchers have identified other issues that may be involved.
- One of them is simply that due to normal biologic processes the precise size and shape of a person's jawbone tends to change over time.
- In regions where the jawbone often becomes smaller (like the area between the lower eyeteeth), since the available space becomes less but the size of the teeth remains the same, there's no way for tooth crowding not to result.
If you're interested in more detailed information, our references page contains a link to Karasawa 2013. Its discussion outlines the topic of tooth crowding fairly extensively.
B) The opinion that all wisdom teeth must go.
Since so many people have their third molars extracted, you may wonder if, in general, it's always the right thing to do.
As an answer, it's easy enough to say that it's not. Many people, even those with poorly aligned or impacted third molars, live their entire life without complication.
But just as always extracting is the wrong choice, so is always retaining t too. Use this link to access our page that discusses issues associated with making a decision to have, or not to have, a wisdom tooth extracted.
Full menu for this topic - ▼
- Wisdom teeth - Which teeth are they? / Classifications (impaction types).
- An outline of valid reasons to have third molars extracted.
- Determining when not to extract third molars.
- The fallacy of "tooth crowding" theory.
- The extraction procedure - Estimating surgical difficulty / Sectioning / Sedation
- Common post-surgical complications.
- Assorted FYI facts about getting your wisdom teeth out.
Related pages -