Wisdom teeth: pain, extraction, should they come out?

Swollen gum at the back of the mouth, a tooth lying sideways on the X-ray, advice to take them all out "just in case": wisdom teeth raise a lot of questions. This guide sums up, in simple words, what the specialist orthodontic references, including the reference textbooks, and the main published studies say. It is here to inform you; it does not replace an examination: every mouth is different.

What are wisdom teeth?

Wisdom teeth are the third molars, right at the back of the mouth: at most four, two at the top and two at the bottom.

They are the last teeth to form and to come in. According to the specialist references, their bud (the tooth forming inside the bone) can be seen on a panoramic X-ray from about age 9. They usually come in during the late teens or in young adulthood, at a very different time from one person to another. Some never come in, and some people have none: an older reference textbook (Bassigny) notes that about 12% of people have no wisdom teeth.

Impacted wisdom tooth: what does it mean?

• A fully impacted tooth stays completely inside the bone or under the gum.
• A partly impacted tooth has started to come in but stays stuck, often against the molar in front of it.

The main cause is a lack of space behind the second molar. Specialist references explain that the jaw grows longer towards the back during growth; if this space stays too small, the wisdom tooth may remain impacted.

This is common: in 380 X-rays of adults at a hospital in India, 54.7% of people had at least one impacted wisdom tooth (Modi et al., 2025, PubMed); this is a single study, and its figures do not apply as they are elsewhere.

An impacted tooth does not always cause problems. But a Cochrane review points out that, over time, it can be linked to inflammation of the gum covering it, tooth decay, gum and bone disease, wear of the neighbouring root (resorption) and, more rarely, a cyst (Ghaeminia et al., 2020, PubMed).

Wisdom tooth pain: common causes

The best-known cause is pericoronitis: inflammation of the gum that partly covers a wisdom tooth that is coming in, most often at the bottom. Food debris and bacteria build up under this small flap of gum. A literature review describes it mainly in young adults aged 20 to 29: pain in one spot, swollen gum, difficulty opening the mouth, sometimes pus (Rolek and Pławecki, 2024, PubMed); this is a descriptive review.

Treatment usually starts in the dental chair, with careful cleaning under the gum. A review of published guidelines concludes that antibiotics should be kept for severe cases, whereas they are often prescribed too easily (Schmidt et al., 2021, PubMed). If the flare-ups keep coming back, removing the tooth may be discussed.

Other causes: decay in the wisdom tooth or in the molar just in front of it, inflamed gums, or a tooth rubbing against the cheek. The pain can spread towards the ear or the throat. Do not take any medicine without advice from a dentist, a doctor or a pharmacist.

Signs that mean you should be seen quickly

An infection around a lower wisdom tooth can, rarely, spread (Bailey et al., 2020, PubMed). See a dentist without delay if you have:

• fever;
• swelling of the cheek, under the jaw or in the neck, especially if it is getting bigger;
• difficulty opening your mouth;
• difficulty swallowing;
• pus, a bad taste that does not go away, or unusual tiredness.

If you have difficulty breathing or swelling that spreads quickly towards the neck, go to the emergency department immediately.

Should wisdom teeth always be removed?

We speak of preventive (or prophylactic) removal when a wisdom tooth is taken out even though it does not hurt and shows no disease.

What the studies say

The 2020 Cochrane review found only two studies comparing preventive removal with simple monitoring of impacted wisdom teeth without symptoms, and the evidence was of low to very low certainty. Keeping these teeth might be linked, in the long term, to more gum problems around the neighbouring molar, but the evidence is very uncertain. The authors' conclusion: no firm answer is possible; the decision should be shared between the patient and the practitioner and, if the teeth are kept, they should be checked regularly (Ghaeminia et al., 2020, PubMed).

The guidelines

In the United Kingdom, the NICE guidelines (2000) advise against preventive removal and keep it for specific reasons. Since then, the average age of patients having surgery has risen from about 25 to 32, and decay has become a more frequent reason for removal (McArdle and Renton, 2012, PubMed; Renton et al., 2012, PubMed). An opinion article criticises these guidelines, which according to its authors were published without solid evidence, and is concerned about decay appearing on the neighbouring molar (Mansoor et al., 2013, PubMed).

The main reference textbook (Boileau) points the same way: no routine removal, but a case-by-case decision, based on age, root development, the space behind the second molar and the direction of the tooth. It recalls the risks of keeping a tooth that has no room: wear of the neighbouring root, a gum pocket.

In short

Do wisdom teeth make the front teeth crooked?

Many people think wisdom teeth "push" the front teeth. The evidence is debated:

• The only comparative trial included in the Cochrane review (77 teenagers analysed, already treated with braces) did not show a notable effect of removal on the dental arch after five years, with a high risk of bias (Ghaeminia et al., 2020, PubMed).
• A meta-analysis of 13 observational studies suggests that lower wisdom teeth might contribute to crowding of the front teeth, but these studies have a moderate to high risk of bias and stronger studies are needed (Palikaraki et al., 2024, PubMed).

Specialist references point out that late crowding of the lower teeth has several causes: a natural forward movement of the teeth with age, the end of jaw growth, and the maturing of the muscles. According to Boileau, the role of wisdom teeth is smaller than once thought: avoiding crowding is not, on its own, a reason to remove healthy wisdom teeth.

With braces, it is different: wisdom tooth removal can be part of the plan, for example to gain space at the back. And according to Boileau, when their eruption is expected at the end of treatment, a fixed retainer (a wire bonded behind the teeth) is rather recommended.

Wisdom tooth removal: how does it work?

1. Examination and X-ray: an examination of your mouth and a panoramic X-ray. A 3D dental scan (cone beam) is kept for cases where it could change the decision; a review of 7 trials did not show that it reduces nerve injuries in general (Robbins et al., 2022, PubMed).
2. Explanation: you should be told about the procedure, the recovery, the risks and the alternatives. Mention any illnesses, treatments, pregnancy and allergies.
3. Anaesthesia: most often local; general anaesthesia is kept for certain cases.
4. The procedure: a tooth that has fully come in is often removed like any other tooth. An impacted tooth requires opening the gum, removing a little bone and sometimes cutting the tooth into pieces; a few stitches close the gum.
5. If the root touches the nerve: one alternative is coronectomy, which removes only the crown and leaves the roots in place. A meta-analysis of 34 observational studies found fewer nerve injuries than with full removal, but slightly more second procedures, about 3.6% (Kang et al., 2025, PubMed).

Depending on how difficult it is, the dentist removes the tooth or refers you to a surgeon.

Normal recovery

After a lower wisdom tooth is removed, pain, cheek swelling and difficulty opening the mouth are common in the first few days (Bailey et al., 2020, PubMed), then they usually ease off gradually. A few general tips:

• Bite on the gauze for as long as you are told; put something cold on your cheek, for short periods, on the first day.
• Eat soft, lukewarm food, on the other side.
• Avoid spitting hard, rinsing vigorously and smoking for the first few days.
• Keep brushing your teeth, gently near the wound.
• Take only the medicines prescribed by your practitioner, exactly as instructed.

Possible complications

Most are uncommon, but you should know about them:

• Dry socket: the blood clot that protects the hole left by the tooth forms poorly or is lost, and strong pain appears a few days later. A meta-analysis of 28 studies estimates it at 6.7% after removal of an impacted lower wisdom tooth, with large differences between studies (Kostares et al., 2024, PubMed). It is treated at the dental practice: go back to see your dentist.
• Infection: fever, swelling that increases after the first few days, pus. Go back to see your dentist quickly.
• Bleeding: slight oozing is normal on the first day; heavy bleeding that does not stop when you bite on gauze means you should call the practice.
• Nerve injury: numbness or tingling of the lip, chin or tongue. In more than 44,000 removals of impacted lower wisdom teeth, it was temporary in 1.20% of cases and lasting in 0.28%; the risk is higher when the tooth is deep and touches the nerve canal (Kang et al., 2019, PubMed).
• The sinus: at the top, impacted wisdom teeth are often close to the sinus (Modi et al., 2025, PubMed); in that case, your practitioner will give you instructions.
• The jaw joint: a reference textbook (Canal) lists this removal among the possible causes of a locked jaw joint.

In practice

1. Have your wisdom teeth checked at your visits, especially in your late teens.
2. Brush the back of your mouth carefully.
3. See a dentist quickly if you have fever, swelling, or difficulty opening your mouth or swallowing; go to the emergency department if you have trouble breathing.
4. Ask why removal is being offered, what the risks are and what the alternative is.
5. If you keep your wisdom teeth, accept regular check-ups.
6. After a removal, follow the instructions and go back to see your dentist if the pain gets worse instead of better.

Frequently asked questions

At what age do wisdom teeth come in?

Usually in the late teens or in young adulthood, at a very different time from one person to another; some never come in, and a panoramic X-ray shows how far along they are.

Should a wisdom tooth that does not hurt be removed?

Not necessarily: studies do not give a firm answer and official guidelines advise against routine removal; the decision is made with your practitioner after an examination and an X-ray, and a tooth that is kept should be monitored.

Does a wisdom tooth coming in move the front teeth?

Its role is debated and seems small: this crowding with age has several causes, and studies do not support removal for this reason alone.

How long do pain and swelling last after removal?

They are strongest in the first few days and then ease off gradually; pain that gets worse instead of better, a fever or swelling that grows means you should go back to see your dentist.

I wore braces: should I have my wisdom teeth removed?

Not automatically: what happens to them depends on the space available, their position and your retainer, and it is often planned from the start of the treatment plan; talk to the practitioner who is following you.