Wisdom teeth

People usually have 4 wisdom teeth, with 2 on each side of the mouth (1 on the bottom jaw and 1 on the top jaw). Some people have fewer wisdom teeth and other people have more.

Wisdom teeth are the last teeth to come through into your mouth. They usually come through between the ages of 18 and 24 years.

Sometimes, a wisdom tooth does not come through properly into your mouth. It can get stuck, either under your gum or as it pushes through the gum. This is called an impacted wisdom tooth.

Problems with wisdom teeth

Wisdom teeth are at the back of your mouth. They can be difficult to clean, which can lead to problems. Some of these problems can cause pain and swelling.

Sometimes, you might not have any symptoms but wisdom teeth can still cause problems in the mouth. People usually get these problems soon after their wisdom teeth come through. Others do not have problems until they are older.

These are the most common reasons why we need to remove wisdom teeth.

Infection of the gum around the tooth

Up to 6 out of 10 people that we see have an infection of the gum around the tooth (pericoronitis). It is the most common reason why we remove wisdom teeth. This type of infection can cause pain and swelling, but sometimes your symptoms are mild.

Tooth decay

Tooth decay (caries) can happen in the wisdom tooth or the tooth next to it. This affects up to 3 in 10 people that we see with wisdom tooth problems.

Tooth decay might not cause immediate problems until it affects the nerve of the tooth. If this happens, an abscess (a collection of pus caused by a bacterial infection) can form and you will have toothache.

Gum disease

Gum disease (periodontal disease) can affect wisdom teeth. Sometimes, a wisdom tooth can contribute to gum disease on the tooth next to it.

Up to 1 in 10 people that we see with wisdom tooth problems have gum disease. You might not have symptoms, but this can still cause problems.


All teeth form within a sack, which can sometimes expand like a balloon. This is called a cyst. The cyst can become larger with time and cause problems. We see this in less than 1 in 100 people with wisdom tooth problems.

Treatment options

We often remove impacted wisdom teeth that cause problems. Sometimes we can treat non-impacted wisdom teeth that are useful, but some still need to be removed.

Read information on wisdom tooth removal.

Resource number: 4131/VER2
Last reviewed: April 2019
Next review: April 2022

Contact us

If you have questions about your wisdom tooth treatment, call the oral surgery department.

Phone: 020 7188 3885, Monday to Friday, 9am to 5pm

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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