Baby teeth: what are they and when should you expect them to fall out?

29 December · 6 minutes

We all know that as infants, you begin with baby teeth and by the age of six, you begin to lose them to make room for your permanent adult teeth. But just because baby teeth are not around for long doesn’t mean they aren’t crucial for the development of your child’s oral health. Baby teeth shape a child's future smile. We will explain everything you need to know about baby teeth, or milk teeth, when babies start teething, and the symptoms, so your little one grows up with a healthy smile.

What are milk or deciduous teeth?

You’ve probably heard of baby teeth, but maybe you’re wondering what milk or deciduous teeth are? Milk teeth and deciduous teeth, and also sometimes primary teeth, are just other terms people use for baby teeth. They all refer to the first set of teeth to erupt in a baby’s mouth. They remain in the mouth until around the age of six and then are replaced by permanent teeth.

The deciduous teeth are responsible for making space in the mouth for adult teeth, which begin to grow in children’s gums. When a child's milk teeth are correctly developed, they directly help grow permanent teeth.

Baby teething and tooth eruption

When can you expect babies to start teething?

Curious about when babies get teeth? You can generally expect to see babies start teething when they are four months old.

Tooth eruption generally starts with the lower incisors. These are the first four primary teeth to grow in. From nine months onwards, the upper central incisors begin to erupt. At around 15 months, the first upper and lower molars then erupt. And then finally, the child’s second primary molars begin to erupt when they’re about two years old.

When babies start teething, the process usually lasts until they are about two and a half years old. However, the first permanent molars do not begin to appear until the age of six.

A teething baby smiling and laughing

Signs of teething in babies

Now that you know when to expect babies to start teething, it’s important to know what the symptoms are. Baby teething symptoms can vary from case to case. Sometimes there will be no signs of teething in babies, while others experience a lot of discomfort.

Here are some common signs and symptoms of teething in babies:

  • Nervousness and irritability
  • Excessive drooling
  • Swollen gums
  • Difficulty falling asleep
  • Loss of appetite
  • Slight fever

If your baby’s discomfort persists for a prolonged period of time it is recommended visiting your pediatric dentist for a check-up.

Why do we have baby teeth?

In order to understand why we humans have baby teeth, we need to understand their three main functions:

  1. They enable the transition from a liquid to a solid diet.
  2. They maintain space for the permanent teeth and contribute to developing the upper and lower jaws.
  3. They facilitate pronunciation while a baby learns how to speak.

How many baby teeth do babies have?

A lot of people wonder how many teeth babies have. In total, there are 20 baby or primary teeth. 10 in the upper arch and 10 in the lower arch. Altogether, these 20 teeth maintain the space for your child’s future smile.

After the first baby tooth falls out, the process of mixed dentition begins, where deciduous and permanent teeth coexist in the mouth.

Smiling girl with missing milk teeth

Baby teeth falling out

What age are kids when they lose their teeth?

If you‚Äôre searching for an answer to ‚Äúwhen do kids start losing teeth?‚ÄĚ you‚Äôre not alone. As babies turn to children, a lot of parents wonder when those baby teeth will start to fall out.

Between the ages of five and six is usually when kids start to lose their teeth, but in some cases, they don’t start losing them until all the way up to the age of 12. During this period of time, the milk teeth coexist with permanent teeth. It's normally expected that by the age of 12 the process of losing teeth and growing in permanent teeth is complete, but again, this can vary. The child’s smile will go from 20 primary teeth to 28 adult teeth, with the absence of the four wisdom teeth that grow in later.

What is the order of losing your baby teeth?

Every child is different, so there is not a one size fits all rule when it comes to how long the milk teeth will take to erupt, develop, or fall out.

Usually, the order of losing baby teeth starts with the incisor and ends with the back molars. However, this can vary from child to child.

It’s usually anticipated that the lower central incisors are the first baby teeth to fall out at about five and a half or six years of age. This is then followed by the lower lateral incisors and the four upper incisors. The next baby teeth to fall out are the lower canines and lower molars; this usually happens around the age of nine or ten. Finally, a year to two later, the upper canines and second molars fall out.

Do kids lose molars?

They do! Around the age of 10 is when kids lose molars. The second molars fall out at approximately 12 years of age. Once the milk molars fall out, they are then replaced by permanent molars around the age of thirteen.

A kid opening their mouth to show adult teeth coming in behind baby teeth

What happens when there’s a tooth growing behind a baby tooth?

When adult teeth start coming in behind baby teeth, it’s called shark teeth. This happens when the baby teeth have not fallen out and are still in place when the new permanent teeth begin to erupt, resulting in a double alignment of teeth during mixed dentition.

This can occur for a number of different reasons. Most commonly, it happens when there is a lack of space in the jaw, a simple deviation of the permanent teeth, or because the roots of the baby teeth have not been absorbed correctly.

Although this situation usually corrects itself, it’s important to visit a pediatric dentist to avoid any problems with crowding or dental malocclusion in the future.

Adults with baby teeth

There are some cases where adults do not lose their baby teeth. The most common cause of this is called agenesis. This is the absence of the permanent tooth that should replace the baby tooth. This can also happen if there has been trauma to the mouth, there is a lack of space for the permanent tooth, or there is poor alignment of the teeth in the jaw.

Although this situation should not cause long-term issues, it is recommended to have a dentist assess it. They will be able to determine if the temporary tooth can be maintained or if it will cause dental problems and should therefore be extracted.

Baby teeth vs. adult teeth

Let’s break down the differences between baby teeth and permanent (adult) teeth.

  • Quantity. One of the biggest differences between baby teeth and permanent teeth is how many you have. There are 20 baby teeth in total. Whereas with adults, there are 32 permanent teeth (when you include the four wisdom teeth).
  • Size. Baby teeth are much smaller than permanent teeth due to the size of a child‚Äôs oral cavity. The roots of baby teeth are also thinner and shorter, which is why they fall out more easily.
  • Composition. Baby teeth have thinner layers of dentine and tooth enamel. This is why you might notice a color difference in baby teeth vs adult teeth -baby teeth are whiter.
Pediatric dentist looking at baby teeth in a child’s mouth

Problems with baby teeth

Even though baby teeth are temporary, it is still important to be aware of the issues that can emerge. Problems with baby teeth can affect the development of the child’s oral health. Some of the most common children’s baby teeth problems are cavities, premature decay, and necrosis.

Toddler tooth decay

Children with cavities is one of the most frequent problems with baby teeth. Many children will experience decay in their milk teeth. The most common causes of toddler tooth decay are:

  • Prolonged use of bottles
  • Transmission of cavity-causing bacteria, as they are contagious
  • Poor feeding
  • A lack of oral hygiene

What causes premature loss of primary teeth?

Premature loss of primary teeth happens due to a number of causes. Tooth decay, an unbalanced diet (especially due to lack of calcium), weak roots, or trauma to the mouth are the most common reasons for losing baby teeth early.

Why are my child’s baby teeth turning black?

Baby teeth turning black is a sign of pulp necrosis. This is when there is damage to the teeth’s nerves caused by a strong impact to the jawbone. Pulp necrosis is not visible at the time of the trauma but is usually visible a few months later when the tooth begins to take on a different color.

If a baby’s tooth or teeth are turning black, it is a visible sign that the nerves to the tooth are dead. However, this does not have to be alarming, and it does not have to affect permanent teeth. If your child has a necrotic baby tooth, it is recommended that you visit your pediatric dentist to assess the situation.

Orthodontics and baby teeth

When considering orthodontic treatment with deciduous teeth, it is always necessary to assess which type of treatment is most appropriate for the child’s stage of development. This also leads to discerning what imperfection(s) need correcting. Depending on the reason for orthodontic treatment, it is best to consult your pediatric dentist for an expert decision.

Girl being shown a children’s orthodontic appliance by a dentist

Can you get braces with baby teeth?

You can have braces or aligners with baby teeth to align the smile. However, because these teeth are temporary and will be replaced by permanent teeth, it may not be a necessary treatment, yet. If there is any dental malposition, such as crooked teeth or diastema, corrective orthodontic treatment would not be of much use as it will not affect the permanent teeth.

Interceptive and orthopedic orthodontics

There are many cases where a child‚Äôs jaw is too narrow or receding‚ÄĒthis leaves a high chance for malocclusion complications or dental malposition once all of their permanent teeth erupt. In these cases, interceptive or orthopedic orthodontic treatment at an early age can be a great choice. Interceptive orthodontics can improve a child‚Äôs physiognomy, prevent severe malocclusion problems, disrupt bad habits, and correct any functional and speech problems. As the child is still developing, it is easier to intervene with treatment to avoid more serious issues long term.

From age seven, after the eruption of the first molars and while the child is still in the growth phase of their permanent teeth, interceptive orthodontic treatments can be started and adapted to the needs of the patient.

Types of issues interceptive orthodontic treatments can treat:

  • Receding jaw
  • Recessed maxilla
  • Narrow palate
  • Open bites

The aim of Impress is that more and more people can enjoy a beautiful and healthy smile. That's why we are constantly expanding our range of treatments, trying to cover all needs. Contact us to find out if we already offer children's treatments at your nearest Impress clinic. You can get in touch by calling 888.490.1421, emailing careteam@uniformteeth.com or by booking your initial consultation online. Discover what Impress can do for you at your nearest clinic.

We’re excited to see you smile!

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Frequently asked questions about baby teeth

How many baby teeth do you lose?

In total, you will lose all 20 baby teeth between the ages of five and 12 years old.

How should you store baby teeth?

Did you know that baby teeth contain high-quality stem cells within the dental pulp? If you want to preserve these stem cells you have up to 48 hours after they’ve fallen out to take them to a tooth bank that specializes in preserving the cells.

Is it dangerous to swallow a baby tooth?

It’s not dangerous to accidentally swallow a baby tooth. The body will dispose of it naturally, and it should not cause any complications.

What are baby teeth made of?

Like permanent teeth, baby teeth are made of enamel, dentine, dental cementum, and dental pulp. However, primary teeth contain fewer layers of each component, making them weaker than permanent teeth.

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