Oral Health›Life stages

Missing and Extra Teeth: Hypodontia and Supernumerary Teeth

Some people are born with teeth that never develop, and some grow extra ones. Here is how common each is, how they are found, how they can affect the bite and smile, and the treatment options.

Updated September 2026·By the OHA editorial team·8 min read·How we write
Key takeaways
  • Hypodontia means one or more teeth never developed. It usually affects adult teeth, most often the wisdom teeth, the teeth either side of the two upper front teeth, and some premolars.
  • Supernumerary teeth are extra teeth. The most common is between the two upper front teeth, and it can stop an adult front tooth coming through.
  • Both are usually found at a dental examination with X-rays. Many cause no problems.
  • Missing teeth can be managed with braces to close or open spaces, then a bridge, denture or, once growth has finished, an implant.
  • Extra teeth are often removed if they cause problems, but some that cause no harm can be left and watched.

Most people have 20 baby teeth and then 32 adult teeth, a 2025 scientific review of extra teeth explains. Some develop fewer, and some develop more. For the usual timing of baby and adult teeth, see losing baby teeth.

Teeth that never develop (hypodontia)

The Oral Health Foundation (UK) describes hypodontia as a condition where some teeth never develop. It uses different terms depending on how many are missing:

  • Hypodontia: one or a few teeth missing (the most common).
  • Oligodontia: six or more teeth missing.
  • Anodontia: all teeth missing, which is very rare.

How common is it?

  • The British Orthodontic Society (BOS) says hypodontia is one of the most common developmental dental conditions, affecting around 2 to 8% of people, and usually affects the adult teeth.
  • Guy's and St Thomas' NHS Foundation Trust says about 1 in 20 people have it.
  • The Oral Health Foundation says it affects a small number of baby teeth and is more common in adult teeth.

Which teeth are usually missing?

The Oral Health Foundation lists the wisdom teeth, the upper lateral incisors (the teeth either side of the two front teeth) and the lower premolars (the teeth between the canines and the back molars). BOS names the upper lateral incisors and some premolars.

Why does it happen?

The Oral Health Foundation and BOS say it often runs in families, and BOS says it can also be linked to developmental issues or certain medical conditions. Guy's and St Thomas' adds that it can happen for no known reason, and that people who have it do not always pass it on to their children. The Oral Health Foundation says it may affect females slightly more than males.

Signs and effects

Guy's and St Thomas' says people with hypodontia may have gaps between their teeth, still have some baby teeth, or have small or pointy teeth.

For many people it causes no concerns, but some do not like the spaces, especially at the front (Guy's and St Thomas'). The American Association of Orthodontists (AAO) says missing teeth can lead to gaps as the teeth around them shift into the space over time.

Extra teeth (supernumerary teeth)

A supernumerary tooth is an extra tooth, beyond the usual 20 baby and 32 adult teeth. Having one or more is called hyperdontia (2025 review). The AAO says extra teeth can be misshapen or come through abnormally.

How common are they?

The 2025 review says reported rates worldwide range from 0.1 to 3.6%, and warns that differences in how studies define and classify extra teeth make the true figure uncertain. A 2022 UK trial protocol in the journal Trials cites a UK figure of 2.6% for extra teeth in the upper front of the mouth. A 2010 review in the Journal of Dentistry (Tehran) says they are more common in males.

Types

  • Mesiodens: an extra tooth between the two upper front teeth (2025 review). The 2010 review says this is the most common type.
  • Extra teeth near the back teeth, beside a molar or behind the last molar (2025 review).

Why do they happen?

The 2025 review says the cause is not completely understood. The most widely accepted theory is overactivity of the tissue that forms teeth, thought to involve both genetic and environmental factors.

What problems can they cause?

The 2025 review says extra teeth are most often found by chance and are generally symptomless. Where they do cause problems, the 2010 review lists:

  • Delayed or blocked eruption of an adult tooth, especially an upper front tooth. The Trials protocol says an upper front tooth that fails to come through usually shows up between 7 and 9, and that an extra tooth (or a similar small growth of tooth tissue) is responsible in about 28 to 60% of cases.
  • Neighbouring teeth being pushed out of position or turned.
  • Crowding, or a gap between the front teeth.
  • Less commonly, a cyst (a fluid-filled sac) or damage to the roots of nearby teeth.

How are missing or extra teeth found?

A dentist can usually spot missing teeth at an examination, and may take X-rays to see which adult teeth are developing under the gums (Oral Health Foundation, BOS). Guy's and St Thomas' says an examination and X-ray are needed to confirm hypodontia. The AAO says orthodontists use a panoramic X-ray to look for extra, missing or impacted teeth, and recommends an orthodontic check at age 7.

The 2010 review says an extra tooth should be suspected if the adult front teeth come through unevenly, or a baby front tooth stays in place for longer than expected. BOS advises dentists to refer children for an orthodontic assessment while they still have a mix of baby and adult teeth if they have hypodontia, extra teeth, or uneven eruption of the upper front teeth, rather than waiting until all the adult teeth are through.

Treatment for missing teeth

The Oral Health Foundation says treatment depends on how many teeth are missing, where the gaps are, your age, and how your bite and smile are affected. Options include:

  • Braces to close the gaps completely, or to open the right amount of space for a replacement tooth later (BOS, Guy's and St Thomas'). See braces and aligners.
  • Bridges or dentures to fill the spaces, once the teeth are in the right position (BOS, Oral Health Foundation). See replacing missing teeth.
  • Dental implants as a long-term fixed replacement when suitable (Oral Health Foundation). Guy's and St Thomas' says an implant is not suitable while you are still growing, and BOS says implants are an option for adults who have finished growing, usually over 21. The AAO notes that an orthodontist can create or hold space for a future implant, but an implant cannot be moved with braces once placed. See dental implants.
  • Reshaping small teeth. Guy's and St Thomas' says tooth-coloured filling material can be added to small or pointy teeth to reshape them. The Oral Health Foundation says a baby tooth that has not fallen out can sometimes be reshaped, or covered with a crown or veneer to improve how it looks. See crowns and veneers.

BOS says orthodontic treatment often starts in the mid-teens, followed by replacement teeth once the braces are finished. After specialist treatment, Guy's and St Thomas' says you return to your own dentist for ongoing care. The Oral Health Foundation advises asking for a written treatment plan and a clear estimate of costs.

Treatment for extra teeth

Not every extra tooth needs removing. The AAO says they often do. The 2010 review says removal is usually advised if the extra tooth is delaying or blocking an adult tooth, pushing teeth out of position, getting in the way of braces, linked to a cyst, or has come through into the mouth. An extra tooth that is found by chance and is causing no harm may be left in place and checked regularly.

The best timing is debated, the 2010 review says. After an extra tooth is removed, the blocked adult tooth often comes through on its own, which it says can take 6 months to 3 years. Sometimes braces are needed to make space, or to guide the tooth into place. The Trials protocol, written in 2022, says no randomised trials had yet compared waiting for the tooth to come through on its own with actively pulling it into place with braces, which is what that trial set out to test. See having a tooth out for what removal involves.

When to see a dentist
  • An adult front tooth has not come through, or one side has come through and the other has not (BOS, Trials protocol).
  • A baby tooth is still in place long after the adult teeth either side have come through. See losing baby teeth.
  • Your child has gaps between the teeth, or small or pointy teeth (Guy's and St Thomas').
  • Teeth are coming through out of position, or crowded.
  • You are unhappy with gaps or the look of your teeth and want to know your options.

Frequently asked questions

Will a missing adult tooth grow later?

If a tooth never formed, it will not grow. The Oral Health Foundation says hypodontia means those teeth are missing, and a dentist can confirm which adult teeth are developing using X-rays. If you are not sure whether a tooth is late or missing, ask your dentist; see losing baby teeth for the usual ages.

Can my child have a dental implant?

Not while they are still growing (Guy's and St Thomas'). BOS says implants are an option once growth has finished, usually over 21. Bridges and dentures are other options (BOS, Oral Health Foundation), and the AAO says an orthodontist can hold space open for a future implant.

Does an extra tooth always need to come out?

No. The 2010 review says one that is found by chance and causes no harm may be left and watched. It is usually removed if it is blocking or displacing other teeth.

Sources

  1. Hypodontia: missing teeth from birth, Oral Health Foundation, accessed September 2026
  2. My missing teeth, British Orthodontic Society, accessed September 2026
  3. When should I refer for an orthodontic assessment?, British Orthodontic Society, accessed September 2026
  4. Hypodontia, Guy's and St Thomas' NHS Foundation Trust, accessed September 2026
  5. Glossary of orthodontic terms, American Association of Orthodontists, accessed September 2026
  6. When should a child see an orthodontist? The age 7 visit, American Association of Orthodontists, accessed September 2026
  7. Teeth spacing: causes, concerns and treatment options, American Association of Orthodontists, accessed September 2026
  8. Supernumerary teeth: a pictorial review and revised classification, Davidson CL and others, Journal of Oral Biology and Craniofacial Research, 2025, accessed September 2026
  9. Diagnosis and management of supernumerary (mesiodens): a review of the literature, Meighani G and Pakdaman A, Journal of Dentistry (Tehran), 2010, accessed September 2026
  10. Study protocol for the management of impacted maxillary central incisors: the iMAC Trial, Seehra J and others, Trials, 2022, accessed September 2026

This article is general information about oral health. It is not a diagnosis or a substitute for advice from a dentist or doctor who knows your situation. If you have pain, swelling, bleeding that does not settle, or a problem that is getting worse, see a dental professional. In an emergency, contact your local emergency service.

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