What are wisdom teeth?

Wisdom teeth (also called 'third molars') usually appear during the late teens or early 20s and sometimes even later in life. They are often the last teeth to come through (erupt) and are found at the very back of the mouth, behind the second molar teeth. Most people have four wisdom teeth - upper right, upper left, lower right and lower left. Some people have no wisdom teeth at all, or may have fewer than four. This tendency to have missing wisdom teeth is often hereditary.

Wisdom teeth that have erupted through the gum into the mouth, just like any other tooth, do not usually require any treatment. However, many people do not have enough space at the back of the jaws for the wisdom teeth to fit. In these situations, the erupting wisdom teeth can become wedged behind the neighbouring tooth, either under the gum or partly through the gum and partly submerged under the bone. This is called an impacted wisdom tooth.

Reasons for removing wisdom teeth include:

  • Lack of room - your dentist will be able to look in your mouth and assess whether there is enough space in your jaw at the back of your mouth for wisdom teeth to fit in. Often, if you have not had any other teeth removed, there is not enough room for the wisdom teeth. Your dentist may recommend removal of the wisdom teeth before they start pushing through and causing problems;
  • Preparation for orthodontic treatment - if you are planning to have orthodontic work done (braces) to straighten your teeth, any impacted wisdom teeth may get in the way and make straightening your other teeth more difficult. In these cases, they are usually removed before or after starting orthodontic treatment. Your orthodontist or dentist will advise you if this is necessary, and;
  • The wisdom tooth is causing problems - if your wisdom teeth have already started to cause problems and they do not appear to have enough room to fit into your mouth, they may be removed. Leaving them in can make the pain, infection or other problems get worse and can damage other teeth.

Wisdom teeth, upper and lower wisdom teeth, impacted wisdom teeth.Impacted wisdom teeth. 

Hereditary

Inherited by an offspring from their parent/s.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Orthodontist

A dentist who specialises in the diagnosis, prevention and treatment of problems in the alignment of teeth and jaws.

Signs and symptoms

Symptoms of infection caused by wisdom teeth include:

  • Pain, swelling and fever;
  • Redness and inflammation;
  • Pus oozing from around the tooth;
  • Swollen and sore lymph nodes under the jaw, and;
  • Difficulty opening the mouth and swallowing.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Lymph nodes

A small organ of the lymphatic system containing many immune cells. Lymph nodes, also known as lymph glands, are the sites where many interactions between immune cells and foreign materials occur.

Pus

A bodily fluid that is the result of an inflammatory response at an infection site. Its colour can range from whitish to yellow to green, depending on the composition. Pus is mainly composed of dead bacteria, white blood cells and cellular debris.

Methods for diagnosis

Before deciding to remove wisdom teeth, it is important to have a thorough examination of your mouth. A detailed history of your previous dental treatment and your general health may be taken down by your dentist. Be sure to tell your dentist of any allergies or health problems you may have.

X-ray

Your dentist may want to take X-rays of your mouth, which are often called OPGs (orthopantomograms). This allows your dentist to assess the presence and position of your wisdom teeth. It will help with planning any treatment for impacted wisdom teeth. 

Your dentist may recommend removal of some wisdom teeth, even before they cause any problems, to prevent issues in the future. 

Allergies

A harmful, hypersensitive immune reaction to usually innocuous environmental substances.

X-rays

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

When to remove wisdom teeth

The best time to remove wisdom teeth is when the problem first appears. In young adults, the roots of the wisdom teeth have not yet fully formed and are easier to remove. The bone surrounding the wisdom teeth is also softer, which makes removal easier and there is less risk of damage to surrounding nerves, bone or other teeth. Young people who are in good health also tend to recover and heal more quickly after surgery or extractions and have fewer complications. If there is infection surrounding a wisdom tooth, your dentist may suggest that you take antibiotics and wait until the infection clears up before having the tooth removed.

What happens during the procedure?

Removing wisdom teeth

There are three options for removal of wisdom teeth, based on your dentist's assessment of your situation:

  • Local anaesthetic - if your wisdom teeth are likely to be easy to remove, or you have only one or two wisdom teeth to remove, your dentist may recommend that it be done in the dental chair with only local anaesthetic. This means that you will have an injection (needle or shot) around the teeth to make them numb, similar to an injection for fillings. You will generally not have any pain during the procedure, but you will be awake and aware of what is happening;
  • Local anaesthetic with sedation - if your wisdom teeth are likely to be reasonably easy to remove, but you are very anxious about the procedure, your dentist may recommend sedation together with the local anaesthetic. Sedation can be in the form of an inhaled substance such as nitrous oxide and oxygen (also called 'laughing gas'), which calms the person during the procedure, or an intravenous (IV) sedation, given by an anaesthetist, or;
  • General anaesthetic - if your wisdom teeth are likely to be difficult to remove, you may prefer to have a general anaesthetic. This is done in a hospital or day-surgery setting and requires an anaesthetist to administer the general anaesthesia and monitor your vital signs. You will be completely unconscious and will not remember the procedure. Since the effects of a general anaesthetic take some time to wear off, you will need someone to drive you home and take care of you after the procedure.

Your dentist or dental specialist will discuss these alternatives with you and tell you which one is suitable for you.

Most general dentists are well equipped and capable of removing uncomplicated wisdom teeth in the dental surgery. Upper wisdom teeth that are erupted into the mouth are usually very easy to remove and rarely cause complications. However, if your dentist believes your wisdom teeth may be difficult to remove or may cause complications, he or she may refer you to see an oral and maxillofacial surgeon. This surgeon is a dentist who has studied further and specialises in surgery of the mouth and jaws. They will advise you on the best way to handle your wisdom teeth.

What to expect when your wisdom teeth are removed

The procedure for removing wisdom teeth will vary, depending on the position and size of your wisdom teeth. An upper wisdom tooth that has fully erupted into the mouth is usually simple to remove and can take less than 15 minutes in the dental chair with just local anaesthetic.

Lower wisdom teeth are usually larger with longer, more curved roots and may require more effort to remove. Even when they are fully erupted into the mouth, they may need to be divided into segments to be removed safely. The bone surrounding lower wisdom teeth is also harder than for upper wisdom teeth. Sometimes a channel of bone may need to be removed around a lower wisdom tooth to allow safe removal of the tooth.

If your wisdom teeth are completely submerged under the gum, the dentist or oral surgeon will need to make a small cut in the gum over the wisdom tooth and remove any overlying bone with a special drill before removing the tooth. The cut in your gums will be stitched closed after the surgery. Some stitches will dissolve after a few days, while others will need to be removed by your dentist or oral surgeon.

What happens after the procedure?

After the tooth or teeth have been removed, you will be asked to rest until the dentist or oral surgeon is satisfied that there is no excessive bleeding and you have recovered from the procedure. If you have had a general anaesthetic in hospital, you will stay until you recover from the anaesthetic before being discharged. A friend or relative will need to take you home and care for you.

Your dentist or oral surgeon may advise you on how to take care of yourself after surgery. You may be advised to rest, eat soft foods, avoid physical exercise for at least 24 hours and avoid drinking alcohol or smoking for 1-2 days.

If you have had IV sedation or a general anaesthetic, driving or operating machinery is best avoided for 24 hours. If you have had a difficult extraction, you may need to take several days off work, school or other duties to rest and recover.

Depending how many teeth you have had removed and how difficult they were, the level of pain after the procedure will vary. Your dentist or oral surgeon will prescribe pain-relief medication for you. Pain usually starts to ease after the second day and less medication will be needed as time goes on. If your pain does not seem to be reducing every day, call your dentist or oral surgeon.

Some bleeding is to be expected after removing a tooth. Applying pressure to the area by firmly but gently biting on a piece of cotton gauze placed over the area will help stem the bleeding. Try not to poke or disturb the area, or bleeding may start again. A small amount of blood oozing from the wound is normal for the first day or two. If bleeding is constant and does not stop with pressure, contact your dentist or oral surgeon immediately.

Some swelling after wisdom tooth removal can be expected. Once again, the simpler the surgery, the less swelling you will experience. More complicated surgery, in which there has been bone removal and incisions in the gums, will result in more swelling. Applying cold packs to the cheeks in the first 24 hours after the surgery can help reduce swelling. More severe swelling can take up to five days to go down. Some people experience bruising after wisdom tooth removal, although this usually occurs in the more difficult cases where bone removal and gum incisions were necessary. Bruising can appear on the cheeks and down the neck and can take a few days to clear.

Keeping your mouth clean is important to prevent infections. It is recommended to continue brushing your teeth and tongue, but gently. Avoid rubbing or touching the area with your tongue or finger.

The removal of wisdom teeth can prevent other teeth being pushed out of alignment. 

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

General anaesthetic

An anaesthetic given to a person to put them to sleep while having an operation or medical procedure. Afterwards, the person regains consciousness and usually has no memory of the procedure. A general anaesthetic is given in hospital by a specialist called an anaesthetist.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Local anaesthetic

A type of medication that, when administered to an area, creates a localised loss of sensation by blocking nerve activity.

Nerves

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

Potential complications

Complications of wisdom teeth removal

As with any type of surgical procedure, wisdom tooth removal has certain risks. By carefully assessing and preparing you for wisdom tooth removal, your dentist or oral surgeon will take care to minimise any potential risks. Although complications are rare, it is important to be aware and informed of any risks.

Infection

An infection of the gum and bone in the area where a tooth has been removed may develop. This is usually a result of food or plaque becoming trapped in the area. Your dentist will advise you how to keep the area clean after wisdom tooth removal. It is important to follow these instructions carefully to prevent an infection. If the area becomes more painful a few days after the surgery with increased redness and swelling, or if you start to develop a fever or feel generally unwell, you may have an infection. Contact your dentist immediately. Antibiotics are usually prescribed to treat an infection, although the area may also need to be flushed out by your dentist if there is debris caught in the wound.

Dry socket

After a tooth is removed, a blood clot forms over the wound. This clot is essential for proper healing to occur. If the blood clot washes away or is disturbed, the underlying bone will be exposed and the wound will not heal properly. This is called a 'dry socket'. A dry socket is extremely painful and throbs constantly. If you feel an increase in pain some days after your extraction, which is not improving, contact your dentist immediately.

Dry sockets are more common in the lower jaw, where the bone is denser and has less blood supply. To avoid a dry socket, follow your dentist's instructions carefully. Take care not to rinse your mouth or spit vigorously for the first few days after the surgery. This may loosen the blood clot. Do not smoke after surgery. Do not brush or poke the wound and take care when brushing nearby teeth, so as not to disturb the blood clot. Treatment of a dry socket involves flushing the area and encouraging a new blood clot to form. New stitches may need to be placed to keep the blood clot in place if the wound has opened.

Damage to nearby nerves

An impacted wisdom tooth may lie very close to nerve bundles within the bone. Sometimes when a wisdom tooth is removed, the nearby nerve may be damaged or bruised. This can result in ongoing numbness, tingling and a loss of feeling in the teeth, gums, lips, chin or tongue, depending on which nerve has been damaged.

In most cases the nerve will recover over time and normal feeling will be restored, although this can take some months. In rare cases, the nerve damage is serious and the numbness or tingling may be permanent. Your dentist or oral surgeon will take detailed X-rays or scans to determine the position of the wisdom teeth in relation to nearby nerve bundles to avoid this complication. Sometimes a computerised tomography (CT) scan is needed to accurately show the position of these nerve bundles. You will be advised whether there is a significant risk of nerve damage in your case before proceeding with surgery.

Sinus problems

The roots of upper wisdom teeth lie very close to the floor of the sinus. When removing upper wisdom teeth, occasionally the floor of the sinus can be disturbed and an opening is made from the sinus into the mouth. This hole usually heals on its own, although sometimes it needs to be packed with a special foam and stitched over to aid healing. You will need to avoid blowing your nose, smoking, sneezing with your mouth closed and sucking on a straw to avoid opening the hole again if this problem occurs.

Damage to nearby teeth or fillings

When a wisdom tooth is removed, some pressure can be put on your nearby teeth. Sometimes they can be tender after the surgery, until you recover fully. In some cases, nearby teeth or fillings can be chipped, particularly if they have very large fillings or are weakened already. This is a rare complication.

Jaw pain

When wisdom teeth are removed, the dentist or oral surgeon sometimes needs to put considerable force on the jaws during the procedure, particularly if the wisdom teeth are difficult to remove. This can cause soreness in the jaw after the surgery, with difficulty opening the mouth and chewing hard foods. While this tenderness is usually temporary, in some cases it can take some months to resolve completely. This is more likely to happen if you already have jaw joint problems. It is important to tell your dentist if this is the case.

Complications of wisdom teeth

Infection

When an impacted wisdom tooth partially breaks through the gum, it can create a gum pocket that traps plaque and food and causes an infection around it. The gums become red and swollen and painful. With time, the infection can spread to the surrounding structures and cause jaw stiffness, restricted opening of the mouth, facial swelling, neck pain and, in extreme situations, difficulty swallowing. The person can feel feverish and generally unwell as their body tries to fight the infection. If not treated, the swelling can encroach on the airways and become life-threatening.

Treatment of an infected wisdom tooth involves your dentist gently cleaning the infected area around the tooth and applying an antibacterial gel. Your dentist will instruct you on how to clean the area and may recommend frequent warm salt-water mouthwashes. Pain-relief medications and antibiotics may also be suggested if the infection is advanced and the pain is severe.

If there is enough room, the wisdom tooth may still push through the gum and into place in the mouth, even if it has caused an infection before. Your dentist may suggest that you wait and see if this happens and the tooth stops causing problems before you consider removing it.

Crowding

A wisdom tooth may put pressure on neighbouring teeth and push them out of their correct position. This is thought to contribute to the crowding of front teeth. It is important to note that even after removing such impacted wisdom teeth, the crowding and movement of other teeth will not be automatically reversed. Treatment from an orthodontist may be needed to correct any crowding that occurs.

Damage to nearby teeth

An impacted wisdom tooth can sometimes keep pushing against the roots of neighbouring molar teeth. This pressure can cause an 'erosion cavity' in the adjacent tooth, whereby the tooth structure is eaten away. The damaged tooth becomes painful and infected and both teeth usually need to be removed. Removal of an impacted wisdom tooth before it starts to cause problems is the best way to prevent this.

Cysts

When a wisdom tooth is impacted or simply remains submerged within the bone and doesn't erupt as normal, it can form a cyst. A thin membrane covers the crown of the unerupted tooth, which occasionally can undergo changes and grow into large cysts of varying types. Some can be very aggressive and destroy large areas of surrounding bone and nearby teeth. They cause a weakness in the bone that can lead to unexpected fractures of the jaw. It is not possible to predict which impacted teeth will result in a cyst or other complication. If such teeth are not going to be removed, it is advisable to check them with an X-ray periodically to ensure they are not causing problems.

Pain

Pressure from wisdom teeth pushing through the bone can cause dull pain in the jaws. This can come and go for a period of some months and can cause considerable discomfort. Pain is also a result of infections associated with wisdom teeth that have pushed through the gum or made contact with nearby molars. An X-ray is usually recommended to determine the cause of this type of jaw pain.

Ulcers

Upper wisdom teeth that are erupting into a tight space can sometimes push out sideways towards the cheek. This can cause an ulcer as the person chews their food and the tooth rubs continuously against the cheek. Often these teeth keep causing problems and need to be removed.

Decay

Food and plaque can easily become trapped around wisdom teeth and nearby teeth, causing tooth decay in one or both teeth. Because of their position so far towards the back of the mouth, wisdom teeth are often difficult to clean and so are more prone to decay and gum disease. If they are partly impacted, food can be pushed down beneath the gum and cause decay in very hard-to-reach places. Sometimes there is no alternative but to remove both affected teeth.

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Computerised tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.

Cyst

A closed sac in or under the skin that contains fluid.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Gum disease

A chronic, progressive disease of the gums caused mainly by bacteria and poor oral hygiene. Early stages are generally asymptomatic, with the advanced stages characterised by loss of gum tissue, supporting bone and eventual loss of teeth.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Nerve bundles

A collection of nerves that pass through the bone or tissues. Usually accompanied by blood vessels.

Nerve

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

Orthodontist

A dentist who specialises in the diagnosis, prevention and treatment of problems in the alignment of teeth and jaws.

Plaque

A thick, sticky, soft mass that adheres to the surface of the teeth and gums and is the primary cause of tooth decay. It is composed of bacteria, food particles and mucin derived from the saliva. It cannot be rinsed off with the flow of water or saliva.

Sinus

A cavity within bone or other bodily tissue. Often refers to the hollow cavities within the facial bones on either side of the nose that filter the air that is breathed in through the nose.

Tooth decay

The process of destruction of the tooth’s surface due to the accumulation of bacterial plaque, which produces acids that break down the tooth structure. The decay forms dark patches on the teeth, which grow into holes or cavities and can become painful if left untreated.

Ulcer

An open sore in the skin or mucous membranes such as those of the stomach lining, intestine or mouth.

X-rays

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Clot

The thickened or solid mass formed from a liquid, such as blood. Blood clots normally form at an injury site to prevent further blood loss.

Prevention

There is no way to prevent impacted wisdom teeth, but to prevent ongoing problems after you have had your wisdom teeth removed, carefully follow the instructions given to you and be sure to attend any follow-up appointments made, to check on your healing and remove stitches if needed.