Shark Teeth in Kids: When an Adult Tooth Comes In Behind a Baby Tooth

Most parents notice it while brushing or when their child smiles for a picture. A new adult tooth is poking through behind a baby tooth that has not fallen out yet, leaving two rows of teeth for a while. Dentists sometimes call these "shark teeth." It usually shows up on the lower front teeth around age 5 to 7, and at our Dandridge and Jefferson City offices we see it every week. In most cases it sorts itself out. In some cases a quick visit makes it easier on everyone.

Why Shark Teeth Happen

Normally, an adult tooth grows in directly under the baby tooth. As it moves up, it slowly dissolves the baby tooth's roots. The baby tooth gets loose, falls out, and the adult tooth takes its spot.

Lower front adult teeth do not always follow that path. They often develop slightly behind the baby teeth, toward the tongue. When that happens, the adult tooth may not dissolve enough of the baby tooth's root on its way up. The baby tooth stays firm, and the adult tooth simply comes in behind it. That is the double row you are seeing.

Shark teeth can also happen with the upper front teeth or the back molars, but the lower front teeth are by far the most common spot.

What to Do at Home First

If you see shark teeth, start by checking how loose the baby tooth is. Have your child wiggle it gently with a clean finger or their tongue.

• If the baby tooth is loose: encourage your child to wiggle it often. Crunchy foods like apples and carrots can help it along. Most loose baby teeth fall out within a few weeks.
• If it is only a little loose: give it time, but keep an eye on it. Check every week or two.
• If it is not loose at all: it is a good idea to have us take a look. A baby tooth with roots that have not dissolved may not come out on its own.

Please do not try to pull a tooth that is still firm, and never use string and door tricks. Pulling a tooth that is not ready can hurt, break the tooth, and make your child nervous about the dentist for years. For a refresher on normal timing, see our guide on when baby teeth fall out.

When to Call Your Dentist

Give us a call if any of these apply:

• The baby tooth is not loose at all when the adult tooth comes in.
• It has been about 2 to 3 months and the baby tooth is still there.
• Your child has pain, swelling, or red, puffy gums around the teeth.
• Food keeps getting trapped between the two rows and is hard to clean.
• Your child has trouble chewing or is avoiding certain foods.
• It is happening with back teeth or several teeth at once.

What We Do at the Visit

First, we look at the teeth and check how loose the baby tooth really is. Sometimes we take a small X-ray to see the roots and make sure the adult tooth is healthy and headed in the right direction. Our article on dental X-ray safety explains why the dose is so small.

If the baby tooth is nearly ready, we may just recommend more wiggling and a recheck. If the roots are still holding on, removing the baby tooth is usually quick and simple. We numb the area well first, and for most kids it is over before they realize it started. For children who are anxious, we talk them through each step, and nitrous oxide (laughing gas) is an option that helps many kids stay calm.

Taking out a stubborn baby tooth gives the adult tooth room to move forward into its proper spot, while the jaw is still growing and things can adjust easily.

Will My Child Need Braces?

Not usually because of shark teeth alone. Once the baby tooth is out, the tongue naturally pushes the adult tooth forward over the following weeks and months. Many teeth that start out looking crooked straighten up quite a bit on their own.

That said, shark teeth can be an early hint that there is not much room in the jaw. If the adult front teeth look very crowded after they settle, we will point it out and talk about whether an orthodontic evaluation makes sense. The American Association of Orthodontists recommends a first orthodontic check around age 7, which lines up nicely with this stage.

Keep Both Rows Clean

While the double row is there, food and plaque love to hide between the teeth. Help your child brush along the gumline of both rows, angling the brush to reach the tooth in back. Using the right amount of fluoride toothpaste helps protect the brand new adult tooth, which has softer enamel for its first couple of years. If the gums look puffy or bleed a little, that is usually a sign the area needs more careful brushing, not less.

The Bottom Line

Shark teeth look strange, but they are a normal part of growing up for a lot of kids. If the baby tooth is loose, give it a few weeks. If it is firm, or nothing has changed after a couple of months, a short visit can take care of it and let the adult tooth settle where it belongs. We are always happy to take a quick look and give you peace of mind.

Common Questions

Are shark teeth in kids normal?

Yes. Adult teeth coming in behind baby teeth is very common, especially with the lower front teeth around ages 5 to 7. If the baby tooth is loose, it usually falls out on its own within a few weeks.

How long should I wait before calling the dentist about shark teeth?

If the baby tooth is loose, it is fine to wait a few weeks. Call if the baby tooth is not loose at all, if it has been about 2 to 3 months with no change, or if your child has pain or swelling.

Will the adult tooth stay behind the other teeth?

Usually not. Once the baby tooth comes out, the tongue tends to push the adult tooth forward into place over the following weeks and months. If the teeth look very crowded after they settle, your dentist may suggest an orthodontic evaluation.