Baby teeth are the first set of teeth a person grows. A full set of adult teeth replaces most people’s baby teeth. In some instances, a person may have a baby tooth that does not fall out and remains until adulthood.

A person’s baby teeth are also known as deciduous, primary, or temporary teeth.

These teeth usually begin falling out around the age of 5 or 6. A person’s adult teeth, or permanent teeth, usually appear to fill the gap.

Some adults have retained baby teeth. This means that one or more of their baby teeth have not fallen out and remain in place in their mouth.

This article will explain how a person can tell if they still have baby teeth, what causes retained baby teeth, and treatment options.

Adult mouth with baby teeth.Share on Pinterest
Photography courtesy of Chikkanarasaiah, Nagarathna & Siddaiah, Shakuntala & Mathew, Somy & Krishnamurthy, Navin & Yumkham, Ratna. (2012). Cleidocranial dysplasia presenting with retained deciduous teeth in a 15-year-old girl: A case report. Journal of medical case reports. 6. 25. 10.1186/1752-1947-6-25.

Some adults retain one or more baby teeth, known as retained deciduous teeth. Around 25% of people have baby teeth for longer than the expected age for losing them.

Baby teeth in an adult can last for many years. However, they may become nonfunctional over time.

The most obvious difference between adult and baby teeth is their size. Baby teeth are smaller than adult teeth. They are also usually whiter, as they have thinner enamel than adult teeth.

Baby teeth sometimes have smoother, rounded edges. When adult teeth begin to emerge, they have distinctive bumps on the topmost edges, which are thought to help them erupt through the gum. These ridges, or “mamelons,” often get worn down over time.

Baby teeth usually begin to emerge around 6 months of age. They continue to emerge up to around 30 months after birth, depending on the type of tooth.

When a child reaches 5–6 years old, adult teeth descend closer to the gum surface. The roots of the baby teeth disintegrate, which makes them loosen and fall out.

By the age of 12–14, most people have lost all of their baby teeth and have a set of 28 adult teeth. The last four teeth, wisdom teeth, usually emerge last, between the ages of 17–21.

Learn more about the types of teeth here.

The most common cause of baby teeth in an adult is the lack of a permanent successor for the tooth. If a person does not have an adult tooth ready to erupt and take the baby tooth’s place, they are more likely to retain it into adulthood.

The most common replacement adult teeth missing are the mandibular second premolars, located at the back of the mouth.

The medical term for missing teeth is “tooth agenesis.” It is more common in females than males, and some people may inherit the condition through their genes. Tooth agenesis has three subdivisions:

  • Hypodontia: Six or fewer teeth fail to develop.
  • Oligodontia: More than six teeth fail to develop.
  • Anodontia: A whole set of teeth fail to develop.

Another cause of baby teeth in adults is ectopic eruption. This is when a tooth does not follow its usual course as it erupts from the gum.

Baby teeth in adults can also be caused by impaction of the successor tooth. This occurs when a tooth remains embedded in the gum tissue or bone longer than it should and fails to emerge.

If an adult has baby teeth and the successor teeth are missing, they can either retain the baby teeth or extract them.

If a person retains the baby tooth, they may undergo some restorative modification. This can include the addition of a molded cap to the top of the baby tooth. This can give it the appearance of an adult tooth.

If a medical professional removes the baby tooth, the individual may opt for one of the following solutions:

  • accepting the presence of a gap where the baby tooth once was
  • using orthodontic procedures to close the gap where the baby tooth once was
  • using autotransplantation of another tooth into the space where the baby tooth once was
  • putting an artificial replacement tooth into the space where the baby tooth once was


Can retained baby teeth cause complications?



The short answer is yes, yet many people live with healthy baby teeth that are completely functional. The most common complication is when an adult loses their baby teeth and the space for an implant-supported or fixed partial crown to replace the baby tooth is inadequate.

Other complications include:

  • Misaligned retained baby teeth: Retained baby teeth are often misaligned. This means they do not line up well with the other teeth. This can make it more difficult to clean them and may lead to cavities developing.
  • Misaligned surrounding adult teeth: A misaligned baby tooth can affect the adult teeth around it. This can cause them to move and become misaligned. If an adult loses a retained baby tooth, the surrounding teeth can shift into that space and affect alignment. This can affect a person’s appearance and may cause their teeth to fail to line up when they close their mouth.
  • Gaps developing between teeth: Retained baby teeth are smaller than a person’s other teeth. This means they can cause gaps and spaces to develop between their teeth.
  • Issues chewing food: The presence of different-sized teeth and gaps between teeth can cause a person to have issues chewing food.
  • Submerging baby teeth: Retained teeth can sometimes become fused to the bone and slowly sink or submerge into the surrounding gum tissue.
  • Issues with bite: Since baby teeth have a narrower width than adult teeth, this can sometimes affect a person’s bite.
Rooz Khosravi, DMD, PhD, MSDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Was this helpful?

If an adult has a baby tooth, they should contact a dentist. A dentist will assess the tooth and decide if treatment is required.

If the tooth and root are structurally and aesthetically sound, the dentist may recommend leaving the baby tooth in place.

To prevent complications, they may also decide to carry out some orthodontic work on the surrounding teeth.

The dentist may also suggest that they remove the baby tooth.

A person can talk with a dentist about retained baby teeth. The dentist may refer them to an orthodontist or prosthodontist, who can give specialist advice and provide them with a personalized treatment plan. Treatment will depend on the cause of the retained teeth.

With the right treatment, an adult with baby teeth can reduce their risk of developing complications.

Baby teeth are the first set of teeth a person grows. Other names for these teeth include deciduous, primary, or temporary teeth.

Baby teeth usually fall out in childhood, but some people retain one or more baby teeth into adulthood.

Baby teeth in adults cause very few issues for some people. However, they may cause aesthetic issues, gaps to form, or difficulties with chewing.

If the baby tooth causes no problems, a person may decide to keep it. However, a dentist may recommend removing a person’s baby teeth.

A dentist can leave a gap where the tooth was, close the gap between the remaining teeth, or place an artificial replacement tooth into the space where the baby tooth was.