Impacted wisdom teeth are wisdom teeth that do not erupt properly. It can lead to overcrowding of the teeth, infections, ear pain, and swelling. There may also be pain and swelling in the gums, tooth decay, and bad breath.

Wisdom teeth, also known as the third molars, are the last teeth to grow in an adult’s complete set of teeth.

Adults typically have 32 teeth. Of these, wisdom teeth, or third molars, are the last to appear. They appear at the end of the upper and lower gums, right in the back of the mouth.

Wisdom teeth typically develop in late adolescence or early adulthood, when a person is between 17 and 21 years. It does not usually cause problems when they appear, except when they become trapped under the gums or in the jaw.

A facial X-ray showing the teeth, with a red circle highlighting an impacted wisdom tooth.Share on Pinterest
Photo editing by Stephen Kelly; Photography courtesy of Coronation Dental Specialty Group/Wikimedia

The human mouth normally does not have room for 32 teeth, which includes the four wisdom teeth, so if wisdom teeth come through, they may cause crowding, infections, ear pain, and swelling.

Generally, people have four wisdom teeth. A person can have between none and four, and in rare cases, individuals may have more than four.

Having a small jaw or mouth with an abundance of teeth does not allow wisdom teeth to come through — they do not fully emerge into the mouth. This can also lead to crowding, infections, ear pain, and swelling.

Wisdom teeth can also grow in an atypical direction, coming out sideways, at an atypical angle, or only partially. Wisdom teeth that grow in a different position can cause pain and damage adjacent teeth. Even if no apparent damage occurs, the angle and position of wisdom teeth can make them susceptible to disease and bacteria buildup, which can lead to infection and decay.

In most cases, people do not need to remove their wisdom teeth as long as they practice good oral hygiene. However, they may need removing if a person or dentist notices changes in the mouth.

An impacted wisdom tooth can cause a range of problems. These include:

Additionally, impacted wisdom teeth can push against other teeth and cause crowding. A person may need orthodontic treatments to straighten crooked teeth.

The tooth may grow into a sac in the jawbone, which fills with fluid, creating a cyst. The cyst can damage the jawbone and nearby teeth and nerves.

Rarely, a noncancerous tumor may form, which means surgery to remove tissue and bone may be necessary.

The second molar, next to the wisdom tooth, becomes more prone to infection if something is pushing against it.

Because of its location, it can be more vulnerable to infections, which can lead to:

  • bad breath
  • earache
  • headache
  • a strange taste in the mouth,
  • toothache
  • swollen gums, which may be redder than usual
  • swollen jaw
  • bleeding gums

More serious infections include cellulitis in the cheek, tongue, or throat. Another infection is gingivitis, the gum disease that results when plaque releases toxins that irritate the gums.

The below remedies could help relieve symptoms.

  • Using pain relievers can help ease pain, but a person should swallow them and not leave them on the sore tooth.
  • A mouthwash of warm water and a teaspoon of salt several times a day can reduce soreness and inflammation.
  • An antibacterial mouthwash, such as chlorhexidine, can help with reducing infections.

If the pain continues, a person should seek medical attention.

A dentist may clean the teeth and prescribe antibiotics, but if the problem returns, the teeth may need removing.

The American Association of Oral and Maxillofacial Surgeons (AAOMS) states that third molars that have links to causing disease should undergo removal. The AAOMS also recommends that practitioners should actively monitor wisdom teeth in case of complications.

Dentists will recommend taking out a wisdom tooth if it causes a person pain and discomfort or if it damages or could damage the adjacent teeth or jaw bone.

In the case of asymptomatic impacted wisdom teeth, practitioners cannot accurately predict which wisdom teeth will cause issues. However, the angle where the tooth erupts and how it pushes against other teeth can offer clues.

Do all wisdom teeth need extracting?

Dentists often leave wisdom teeth alone if they are healthy, fully erupted, and in the appropriate positions and a person can easily clean them.

However, many dentists and oral surgeons in the United States suggest removing impacted wisdom teeth as a preventative measure against infection, such as gum disease and tooth decay.

An AAOMS review also suggests that having a wisdom tooth is more likely to cause a worsened periodontal status than not having one.

A dentist should also remove impacted wisdom teeth if they will hinder the other teeth from developing properly.

Previously, people underwent removal of their wisdom teeth, whether or not they were causing any problems. There is still an ongoing debate on whether to remove teeth that are not causing symptoms or to leave them alone.

However, in a 2021 study, only 28% of the third molars underwent removal, while 76.4% had justifiable reasons for their removal.

In a 2017 study, almost half of the participants receiving referrals for surgery showed no symptoms, while 36% received referrals for preventive purposes.

What to expect at the dentist

An oral surgeon will remove the wisdom tooth through surgery if necessary. The dentist will take an X-ray of the entire mouth to see how the roots lie and how the tooth is growing.

The removal may occur at a dentist’s surgery or as an outpatient at the hospital. How straightforward the operation is will depend on the position of the tooth or teeth that need removing.

Before the operation, a healthcare professional will first evaluate a person for allergies, existing medical conditions, and intolerances. They will also disinfect the operating area and the mouth.

Some may also ask the patient to take antibiotics before and after surgery to reduce the risk of infection.

The dentist will inject a local anesthetic to numb the tooth and the surrounding area. Then, they will make an incision in the gums to expose the tooth and bone. After this, they will use a dental drill to divide the tooth into sections to make it easier to remove.

It is important to relax and avoid alcohol and smoking for at least 24 hours to ensure there are no bleeding issues.

Wisdom teeth usually become impacted or trapped in the jaw bone or gums because of a lack of space in the mouth.

Another common reason is the teeth coming out at a different angle. A 2018 study shows that genetics may play a role in the position of upper wisdom teeth.

Impacted wisdom teeth can grow differently, depending on how the teeth grow:

  • Mesioangular impaction: This means the wisdom tooth grows at an angle towards the front of the mouth.
  • Vertical impaction: This refers to when the wisdom tooth does not break through the gum line.
  • Distoangular impaction: This means the wisdom tooth grows at an angle towards the back of the mouth.
  • Horizontal impaction: This means the wisdom tooth grows at a 90-degree angle and into the roots of the molar next to it.

Mild problems, such as swelling, bleeding, bruising, and pain, after the extraction of wisdom teeth are common, but they are not usually serious.

However, complications may also occur, which include the below.

Dry socket

A dry socket, or alveolar osteitis, is when a blood clot does not form properly in the socket after removing the wisdom tooth. It can also occur if the clot becomes dislodged before the wound has healed.

It occurs in up to 38% of people who have wisdom tooth surgery.

This can lead to throbbing pain. It usually results from patients not following the dentist’s instructions, smoking, rinsing the area too soon after surgery, sucking on it, or touching it with the tongue.

Nerve injury

Nerves can undergo injury during the removal procedure. Depending on the affected nerve, nerve injury can lead to numbness or paralysis in the lip, tongue, or cheek.

This is most often temporary but can be permanent if the injury is severe.

Damage to adjacent teeth

Around 1 in 100 people can experience lasting damage from the procedure, including damage to adjacent teeth. However, this largely depends on the extent of the surgery.


Sometimes, removing the wisdom tooth can cause a fracture in the maxillary tuberosity, which is just behind the upper wisdom tooth.

A lower jaw fracture, or mandibular fracture, can occur during surgery or within 4 weeks after surgery.

When a wisdom tooth does not erupt from the gums properly, dentists refer to this as an impacted wisdom tooth. This can result in gum and jaw pain, swollen gums, and general discomfort.

To help ease these symptoms, an individual can take pain relievers, rinse the mouth using a saline solution, or use an antibacterial mouthwash.

A person who develops an impacted wisdom tooth should contact a dentist who may suggest removing it. After surgery, an individual should follow all care instructions the dentist provides to avoid complications such as dry socket.