My Child's Adult Teeth Are Coming In Behind the Baby Teeth. What's the Next Step?

You were looking in your child’s mouth for something completely unrelated, and there they were — a second row of teeth coming in behind the bottom front baby teeth. It looks alarming. It has an alarming nickname, too: parents call them “shark teeth.”

Here’s the short version before anything else: this is common, it is usually temporary, and in most children it sorts itself out without any treatment at all.

What’s Actually Happening

Baby teeth are supposed to come loose because the permanent tooth underneath pushes up against the root and gradually dissolves it. When the root has mostly disappeared, the baby tooth wobbles and falls out, and the permanent tooth arrives in the space it left.

Sometimes the permanent tooth takes a slightly different path. Instead of coming up directly underneath, it erupts just behind the baby tooth — on the tongue side. The baby tooth’s root doesn’t get the same pressure, so it doesn’t dissolve on schedule, and for a while your child has two teeth where you expected one.

It shows up most often with the bottom front teeth, usually somewhere around ages five to seven, right when the first permanent teeth are arriving.

Why It Usually Resolves on Its Own

Two things tend to happen without anyone intervening.

The baby tooth gets loose anyway. The root keeps breaking down, just on a slower timeline, and the tooth eventually comes out the way it was always going to.

And the permanent tooth drifts forward. The tongue rests against these teeth constantly, and that steady, gentle pressure is often enough to walk the new tooth into its proper position once the baby tooth is out of the way.

That’s why the usual advice is patience rather than action.

What You Can Do at Home

Let your child wiggle it. Clean hands, gentle pressure, as often as they like. This is the single most useful thing, and most kids are enthusiastic about the job.

Keep brushing the area properly. Two teeth close together create a spot that traps food easily, and gums get puffy there quickly. This is a good moment to revisit brushing and flossing technique rather than letting your child rush past a tender area.

Don’t pull it yourself. If the tooth isn’t ready, forcing it hurts and accomplishes nothing.

When to Have It Looked At

Most of the time this needs nothing. Make an appointment if:

• The baby tooth isn’t loosening after several weeks of the permanent tooth being clearly visible behind it.
• Your child is in pain, or the gum around the area is swollen, red, or bleeding beyond the odd bit of brushing blood.
• The permanent tooth isn’t moving forward once the baby tooth has come out.
• You’re already seeing crowding elsewhere — teeth overlapping, rotating, or clearly short of room.
• It’s happening with several teeth at once, rather than one or two.

Whether a baby tooth needs help coming out is something an exam determines, not an article. The same goes for how long a particular tooth will take to settle into place. What’s worth knowing is that the situation is routine and the answer is usually reassuring.

This Is What an Age 7 Check-Up Is For

The American Association of Orthodontists recommends a first orthodontic evaluation around age seven. That timing isn’t arbitrary — it’s when enough permanent teeth have arrived to show how the rest are likely to come in, while there’s still plenty of growth left to work with.

A visit like this is mostly about information. We look at how the teeth are erupting, whether there’s room for what’s still coming, and how the bite is developing. Most of these evaluations end with monitoring rather than treatment, and that’s a genuinely good outcome — it means nothing needs doing yet.

If something does need attention, catching it while a child is still growing usually means simpler, shorter treatment than the same problem would need later.

The Reassuring Part

A double row of teeth looks like a problem and usually isn’t one. It’s a timing quirk, and time is generally what fixes it.

But if the baby tooth is stubborn, if your child is uncomfortable, or if you’d simply rather have someone look than keep wondering, schedule a consultation with Nexus Orthodontics in New Hyde Park. Dr. Fung will tell you plainly whether this is something to watch or something to act on.

— Dr. Shauna Fung, DDS, Board-Certified Orthodontist Nexus Orthodontics, New Hyde Park, NY