Why Is My Child’s Adult Tooth Behind Baby Tooth?

Your child opens their mouth to show off a wobbly tooth, and there’s already a second tooth poking through behind it. Two rows of teeth in one small mouth can look alarming at first glance, but this is a genuinely common part of childhood tooth development. Knowing why it happens, and what usually needs to be done about it, can take a lot of the worry out of the situation.

The Short Answer: It’s Usually Harmless “Shark Teeth”

An adult tooth behind baby tooth is commonly nicknamed “shark teeth,” after the way sharks have rows of teeth behind one another. It happens when the permanent tooth starts coming through before the baby tooth above it has fallen out or become loose enough to make way. In most cases, this resolves on its own within a few weeks to a couple of months as the baby tooth loosens and comes out, letting the tongue gently guide the new tooth into position.

What Are Shark Teeth in Children?

Shark teeth children experience is technically known as a type of ectopic eruption. Normally, a coming-through permanent tooth presses on the root of the baby tooth above it, which causes that root to dissolve and the baby tooth to loosen and fall out. With shark teeth, the permanent tooth emerges slightly behind rather than directly beneath the baby tooth, so the root isn’t dissolved in the usual way and the baby tooth stays firmly in place for a while longer.

A children’s dentist can confirm what’s happening at a routine check-up if you’d like it looked at, particularly if you’re not sure whether what you’re seeing matches the typical pattern.

How Common Is This, and Which Teeth Are Affected?

Shark teeth are far more common than most parents expect, and they tend to show up during a fairly predictable window of childhood development. A few things worth knowing:

• It most often happens with the lower front teeth, usually somewhere between ages five and seven
• It can also occur with upper front teeth, and occasionally with molars, though this is less common
• Some children experience it with just one tooth, while others notice it happening with a few teeth around the same time
• It tends to be more noticeable with lower teeth simply because they’re easier for parents to see when a child opens their mouth

None of this variation changes the overall outlook. Whether it’s one tooth or several, the same general process and timeline usually applies.

Why Does a Double Row of Teeth Happen?

A double row of teeth generally comes down to a fairly ordinary quirk of development rather than anything being wrong. A few contributing factors include:

• Mild crowding in the jaw, which can push the emerging tooth slightly out of line
• A family tendency toward this pattern, since it can run in families
• Simple variation in how quickly the baby tooth’s root dissolves compared to how fast the adult tooth is coming through

Shark Teeth vs Other Reasons for Crowded Teeth

Shark teeth are a transitional stage tied to one specific tooth not shedding on schedule, and it typically resolves once that baby tooth is out of the way. 

Ongoing crowding, by contrast, tends to involve the jaw simply not having enough space for all the adult teeth long term, which is a separate issue that may need orthodontic assessment down the track rather than something that self-corrects in a matter of weeks.

Our guide on why baby teeth are so important covers how baby teeth hold space for the adult teeth coming in behind them, which is useful background for understanding why losing one too early, or keeping one too long, can have knock-on effects either way.

Is Wobbly Baby Tooth Removal Ever Needed?

Wobbly baby tooth removal isn’t usually necessary straight away, since most cases resolve without any intervention. A dentist may consider removing the baby tooth if:

• It hasn’t loosened or fallen out on its own within a couple of months
• The baby tooth shows no signs of movement at all
• There’s crowding severe enough to affect how the adult tooth is settling into place
• Your child is having ongoing difficulty cleaning the area properly because of the two rows

Even then, removal is usually a straightforward procedure rather than anything complex. It’s typically done under local anaesthetic in a routine appointment, and most children recover quickly with only mild, short-lived tenderness afterwards.

Healthdirect’s guide to looking after your baby or child’s teeth also has some general background on how baby and adult teeth develop if you’d like further reading.

What Should You Do at Home?

While you wait to see whether the baby tooth loosens naturally, a few simple habits can help:

• Encourage your child to gently wiggle the baby tooth with clean fingers or their tongue
• Keep brushing the area as normal, being gentle around the two rows of teeth
• Avoid trying to pull the tooth out yourself, since this can sometimes disrupt the process rather than speed it up
• Reassure your child that this is a common, temporary stage rather than something to worry about

Our guide on how paediatric dentists support children’s dental development covers this kind of monitoring in more detail if you’d like some further background.

What Happens at a Dental Check-Up for This?

If you bring your child in specifically because of a double row of teeth, the appointment is usually fairly simple. Your dentist will look at how loose the baby tooth is, check the angle and position of the adult tooth coming through, and get a sense of how much room is available in the jaw. In most cases, this is enough to confirm that things are on track and that no action is needed yet. 

Your general dentist can usually cover this as part of a regular check-up rather than requiring a dedicated appointment, which makes it easy to keep an eye on alongside your child’s other routine dental care.

When Should You See a Dentist About It?

Most cases of shark teeth settle within a few weeks without treatment, but it’s worth booking a check-up if:

• The baby tooth hasn’t loosened or fallen out after around two to three months
• Your child seems to be in pain or discomfort
• You notice swelling, bleeding beyond normal wobbly-tooth bleeding, or signs of infection
• Cleaning the area has become genuinely difficult due to crowding

Better Health Channel’s guide to teeth development in children confirms that permanent molars commonly come through behind baby teeth from around age six, which is a normal and expected part of the process rather than a sign that something has gone wrong.

Frequently Asked Questions

Is an Adult Tooth Behind Baby Tooth Always Something to Worry About?

No, this is a common and usually temporary stage of development. This is general information, so it’s still worth keeping an eye on it and mentioning it at your child’s next check-up if the baby tooth doesn’t loosen within a couple of months.

Can I Just Pull the Baby Tooth Out Myself?

It’s generally better to let your child gently wiggle the tooth rather than forcing it out, since pulling a tooth before it’s ready can occasionally cause discomfort or bleeding. This varies case by case, so if it’s genuinely stuck, a dentist can remove it more comfortably.

Will Shark Teeth Affect How My Child’s Adult Teeth Line Up Later?

In most cases, no, since the tongue and jaw growth usually guide the adult tooth into its normal position once the baby tooth is out of the way. Results vary between individuals, so ongoing crowding or alignment concerns are worth monitoring at regular visits.

Does This Happen With Back Teeth Too, or Just Front Teeth?

It’s most commonly seen with the lower front teeth, but it can occur elsewhere in the mouth as well. This varies between children, so any double row of teeth is worth mentioning to your dentist regardless of location.

Do You See Families From Alkimos and Clarkson at Your Butler Clinic?

Yes, our team welcomes families from Alkimos, Clarkson and the wider Butler area at our clinic as a children’s dentist Butler families can visit for this kind of check-up. As with any dental development question, an in-person assessment is the most reliable way to understand what’s happening for your child specifically.

Book a Check-Up for Your Child’s Growing Teeth

If you’ve noticed a double row of teeth in your child’s mouth, or you’d simply like a professional opinion before deciding whether to wait it out, our team is happy to take a look. Book an appointment online to get started, or reach out to the practice with any questions beforehand.