Wisdom teeth

People usually have 4 wisdom teeth, 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 the mouth. These usually come through between the ages of 18 and 24 years.

A wisdom tooth can fail to come through properly into the mouth. It can become stuck, either under the 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 the mouth and can be difficult to clean, which can lead to problems. Some of these problems can cause pain and swelling.

Other wisdom teeth have no symptoms at all, but can still cause problems in the mouth.

People usually develop these problems soon after their wisdom teeth come through, but some do not have problems until they are older.

These are the most common reasons why wisdom teeth are removed.

Infection of the gum around the tooth

An infection of the gum around the tooth (pericoronitis) happens in up to 6 out of 10 people that we see. It is the most common reason wisdom teeth are removed. This type of infection can cause pain and swelling, but sometimes symptoms are mild.

Tooth decay

Tooth decay (caries) can happen in the wisdom tooth or the tooth next to it. We see this in up to 3 in 10 people with wisdom tooth problems.

This might not cause immediate problems until the tooth decay affects the nerve of the tooth. If this happens, an abscess can form and you will have toothache.

Gum disease

Wisdom teeth can be affected by gum disease (periodontal disease) or contribute to gum disease on the tooth next to it. This happens in up to 1 in 10 people we see with wisdom tooth problems. This might not cause symptoms, but it can still cause problems.


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

Treatment options

Impacted wisdom teeth that cause problems will often be removed. Non-impacted wisdom teeth that are useful can sometimes be treated, 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.

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