Shark teeth are permanent teeth that come in behind baby teeth that have not fallen out yet, creating a double row. It is common, especially with the lower front teeth, and the baby tooth often loosens on its own within a few weeks.
What Are Shark Teeth in Kids?
The nickname comes from sharks, which grow rows of teeth one behind the other. In children, it describes a permanent tooth that erupts on the tongue side (or occasionally the cheek side) of a baby tooth instead of directly underneath it. For a while, your child has two teeth trying to occupy roughly the same spot.
Parents usually notice it during brushing or when their child smiles wide for a photo. A new, slightly larger and ridged tooth pokes through the gum behind a baby tooth that still looks firmly attached. It can look alarming, but in most cases nothing is wrong with either tooth.
Shark teeth show up most often between ages 5 and 7, when the lower front baby teeth are the first to go. The same thing can happen later with the upper front teeth or even the back baby molars, though that is less common.
Why Do Permanent Teeth Come In Behind Baby Teeth?
Normally, a permanent tooth pushes up against the root of the baby tooth above it. That pressure slowly dissolves the baby tooth’s root, which is why a baby tooth gets loose and eventually falls out with almost no root left. When the permanent tooth takes a slightly different path, it misses most of the baby root, so the baby tooth stays firm while the new tooth slips out behind it.
The lower front permanent teeth naturally develop a little behind the baby teeth, toward the tongue, so this path is especially easy for them to take. Other contributing factors include a jaw that is still catching up in width, baby teeth with long or stubborn roots, and simple variation from one child to the next.
Crowding can play a role too. If the jaw does not yet have much spare room, the new tooth may come in wherever it finds space. That is one reason Dr. Mitchell pays attention to how much room is left as each permanent tooth arrives.
Is It a Problem If My Child Has Shark Teeth?
Usually not. Once the baby tooth comes out, the tongue gently pushes the permanent tooth forward into the gap, and it typically settles into line over the following weeks and months. Many children never need any treatment at all.
It becomes more of a concern when the baby tooth is not loose at all, when it has stayed put for a long stretch after the permanent tooth appeared, or when the new tooth looks noticeably crooked or crowded. Two teeth in one spot also trap food and plaque, so the gumline in that area can get puffy and tender if it is hard to clean.
Our post on when kids lose their baby teeth covers the normal loss sequence, which helps you judge whether a stubborn baby tooth is just a little late or truly stuck.
Should I Wait or Have the Baby Tooth Pulled?
The answer depends mostly on whether the baby tooth is loose. A wiggly baby tooth is already on its way out, and encouraging your child to wiggle it with clean fingers or their tongue is often all that is needed. A baby tooth that is still solid with no movement at all may need help.
| What you see | What it usually means | What to do |
|---|---|---|
| Baby tooth is wiggly, new tooth just showing | Normal shedding, a little out of order | Let your child wiggle it and keep brushing the area |
| Baby tooth firm, new tooth halfway in | The baby root is not dissolving on its own | Call us so Dr. Mitchell can check it |
| Gums red, sore or swollen around both teeth | Plaque and food trapped between the rows | Brush gently, then have it looked at |
| New tooth looks very crooked or crowded | The arch may be short on room | Ask about spacing at your next visit |
| Baby tooth gone, new tooth still behind the line | The tongue is still moving it forward | Give it time and mention it at the checkup |
If the baby tooth does need to come out, it is usually a quick visit. Dr. Mitchell, a board-certified pediatric dentist, numbs the area so your child feels pressure rather than pain. For a nervous child, sedation options for kids are available at our office.
How Does a Pediatric Dentist Check Shark Teeth?
At the visit, Dr. Mitchell looks at how loose the baby tooth is, how far the permanent tooth has erupted and whether there is enough room for it to move forward. She may take an X-ray to see how much root the baby tooth still has and to confirm the permanent tooth is developing normally.
This kind of check is part of a regular exam. During kids’ checkups and cleanings she watches whether baby teeth are coming in and falling out on schedule and whether there is room for the permanent teeth behind them, so a double row is often spotted early.
You can help by snapping a quick photo when you first notice the new tooth. Being able to compare how things looked on day one with how they look a few weeks later makes it easier to tell whether the permanent tooth is moving into place.
What If There Is Not Enough Room for the New Tooth?
Sometimes the permanent tooth is simply bigger than the space the baby tooth leaves behind. Permanent front teeth are larger than baby teeth, so a child with a tightly packed baby smile may not have much spare room. In that case, the tooth may come forward but stay twisted or overlapped.
Mild crowding in the front teeth often improves as the jaw grows and the neighboring teeth arrive. When it does not, guiding the way teeth erupt early can be easier than correcting crowding later. We offer custom oral appliances for kids, such as expanders that widen a narrow upper jaw and create space for crowded teeth, as well as bands and loops that hold space when a baby tooth is lost too soon.
If a baby tooth is lost early, a space maintainer may be needed to keep neighboring teeth from drifting. Our space maintainer guide explains how that works.
How Can I Keep Shark Teeth Clean?
A double row is harder to clean than a single one, and the space between the two teeth collects plaque quickly. A few small changes at home help:
- Angle the brush. Tilt a soft brush so the bristles reach the inside surface of the new tooth and the back of the baby tooth.
- Brush longer in that spot. Give the double row a few extra strokes twice a day.
- Floss carefully. Slide floss down between the two teeth if your child tolerates it.
- Watch for soreness. If brushing makes your child flinch, use a lighter touch, but do not skip the area.
Clean gums also make it easier for the baby tooth to loosen and for your child to keep wiggling it without discomfort.
Frequently Asked Questions
Do shark teeth hurt?
Usually not much. Your child may feel some tenderness as the new tooth pushes through the gum, and the gum can get sore if food gets packed between the rows. Steady pain or swelling is worth a call.
How long can I wait for the baby tooth to fall out?
If the baby tooth is loose, give it time and let your child wiggle it. If it is firmly in place and does not seem to be loosening over several weeks, call us so Dr. Mitchell can take a look.
Will the permanent tooth stay crooked?
Most move forward into place once the baby tooth is gone, guided by the tongue. If a tooth stays out of line, we can talk about whether the arch has enough room and what options fit your child.
Can shark teeth happen with back teeth?
Yes, though it is less common than with the front teeth. Baby molars that do not loosen as the premolars come in may need to be checked with an X-ray.
Book a Shark Teeth Check in Frisco
If you have spotted a double row of teeth in your child’s mouth, our team can tell you whether to wait or act. Book a visit online or call (214) 872-3434. Frisco Mini Molars is at 5110 Eldorado Parkway, Suite 600, Frisco, TX 75033, and we see children from age 1 through 16.
