Impacted tooth

What is an impacted tooth?

An impacted tooth is one that doesn't break through the gum and move into place as it should. Instead, it stays partly or fully trapped in the gum tissue or jawbone, most often affecting wisdom teeth or canines (the pointed teeth either side of your front teeth).

What are the symptoms of an impacted tooth?

Some impacted teeth cause no symptoms at all and are only found on an X-ray. When symptoms do occur, they may come and go, or be persistent, and can include:

• red, swollen or bleeding gums around the area
• jaw pain or tenderness, or pain when opening your mouth
• a prolonged headache or jaw ache
• bad breath or a bad taste in your mouth
• a visible gap where a tooth hasn't come through
• swollen glands in your neck

As the gum over an impacted tooth swells and then settles down again, it can sometimes feel as though the tooth started to come through and then went back down.

What are the causes of an impacted tooth and who is at risk?

Teeth usually become impacted because there isn't enough room for them to come through properly, or because they're growing at the wrong angle. Common contributing factors include:

• a jaw that's too small to fit all your teeth, including your wisdom teeth
• overcrowding from neighbouring teeth
• teeth that are twisted, tilted or displaced as they try to come through
• an obstruction, such as an extra piece of tooth tissue or a baby tooth that hasn't fallen out

Family history can play a role too, though for some people no clear reason is ever found. Impacted teeth are extremely common, particularly wisdom teeth, which are the last teeth to come through and often don't have space.

Are there different types of impacted tooth?

Dentists describe three main types, based on how far the tooth has come through:

• Soft tissue impaction: the tooth has come through the jawbone but hasn't broken through the gum
• Partial bony impaction: part of the tooth has come through the jawbone, but some of it stays trapped and no part breaks through the gum
• Full bony impaction: the tooth stays completely trapped in the jawbone, with no part erupting through the bone or gum

Wisdom teeth and canines are affected most often. Impacted wisdom teeth are extremely common, affecting around 9 in 10 people at some point by their late teens or early 20s. Impacted canines are less common, affecting around 2–3% of people, most often in the upper jaw.

How is an impacted tooth diagnosed?

Your dentist will usually notice during a routine check-up if a tooth hasn't come through when it should have, or if the gum and surrounding tissue look swollen or otherwise unusual.

To confirm this and see exactly where the tooth is, they'll take a dental X-ray, sometimes followed by more detailed 3D imaging. This shows whether the tooth is there at all, where it's positioned, and whether it's affecting any nearby teeth or roots.

How is an impacted tooth treated?

Non-surgical treatments

If an impacted tooth isn't causing any problems, your dentist may simply monitor it at your regular check-ups rather than treat it straight away.

For some children and teenagers with an impacted canine, an appliance to create more space in the jaw can help guide the tooth into position on its own, avoiding the need for further treatment.

Surgical treatments

If an impacted canine hasn't moved too far from its correct position, it can often be guided into place using a combination of surgery and braces. This usually involves:

• a surgical procedure to uncover the tooth: either creating a small window in the gum so the tooth is visible, or attaching a small gold chain to it
• fitting fixed braces, which are then used to gently pull the tooth into line with the rest of your teeth, a process that usually takes 2–3 years

This approach works for most teeth treated this way, though occasionally a tooth is too firmly stuck in the bone for braces to move it and a different solution has to be found.

If a tooth is too far out of position to be aligned or if it's a wisdom tooth causing pain, infection or damage to nearby teeth, removal (extraction) is usually recommended instead. This is typically done as an outpatient procedure under local anaesthetic or sedation and antibiotics may be prescribed first if there's an infection.

When should I see a doctor?

See your dentist if you notice pain, swelling, discharge or a fever around a tooth that hasn't fully come through, or any new or worsening symptoms near an impacted tooth you already know about.

If you have signs of infection around an impacted tooth, get it looked at promptly rather than waiting, as an untreated infection can spread to other parts of the body and become serious.

Otherwise, regular dental check-ups, typically every six months, are usually the best way to keep an eye on an impacted tooth that isn't currently causing problems.