Two Rows of Teeth: The Baby Tooth That Would Not Let Go

Quick answer: An adult tooth erupting behind a baby tooth — "shark teeth" — is common and usually harmless. If the baby tooth is loose, wiggling it out solves it. If it is firm and the adult tooth is well behind it, a simple extraction lets the new tooth move forward on its own.

The call

A mother in Givat Sharett sent a photograph on WhatsApp with the message: "Is this normal?" Her seven-year-old, Ayala, had two lower front adult teeth coming up behind two baby teeth that were still solidly in place. Two rows of teeth, plainly visible.

It looks dramatic in a photograph. It is one of the most common things we are asked about in this age group.

What we found

Both lower central incisors present and firm, with the permanent centrals erupted about halfway, sitting distinctly behind them on the tongue side.

Why this happens is a matter of geometry. The permanent lower incisors develop behind and below their baby predecessors. Normally, as the adult tooth pushes up, its pressure resorbs the baby tooth's root until nothing is left to hold it and it falls out. If the adult tooth erupts slightly too far back, it misses the root, the root does not resorb, and the baby tooth stays firmly anchored while the adult tooth comes up alongside it.

Two things determine what to do:

Is the baby tooth loose? If it has any mobility, the root is resorbing and it will come out. Encourage wiggling, give the child an apple, and wait a few weeks.

How far back is the adult tooth? Slightly behind is fine — the tongue naturally pushes it forward into position once the baby tooth goes. Significantly behind, or if it has already tilted, may need orthodontic attention later.

Ayala's baby teeth were completely firm with no resorption on the x-ray. They were not coming out on their own.

What we did

Extracted both lower baby incisors under local anaesthetic. Baby front teeth with intact roots still come out easily — a few minutes each, and children of that age generally manage well when the appointment is handled calmly and honestly.

We also gave her a simple exercise: push the new teeth forward with the tongue, several times a day. The tongue is a strong muscle, and in a seven-year-old with space available it does most of the repositioning by itself.

We did not refer her for braces, and we said so explicitly, because a lot of parents in that situation arrive expecting to be told they will need orthodontics. At seven, with adequate arch space, the teeth almost always sort themselves out.

The outcome

Within eight weeks both permanent incisors had drifted forward into alignment. At the twelve-month review they were in normal position and no orthodontic treatment was needed.

What to do if this happens to you

1. Do not panic. It is common and usually resolves.
2. Check whether the baby tooth is loose. If it is, encourage wiggling — clean hands, gentle, several times a day.
3. Give them crunchy food. Apples, carrots and corn on the cob do useful work.
4. See a dentist if the baby tooth is firm after a few weeks, or if the adult tooth is well behind the arch.
5. Do not try to pull out a firm baby tooth at home. Loose is fine; firm needs anaesthetic.
6. Encourage the tongue exercise afterwards. It genuinely helps.

Adult tooth coming through behind a baby tooth? Send Ramat Beit Shemesh Urgent Dental Care a photo on WhatsApp https://wa.me/972559858845 or call 055-985-8845. Harav Kook 28/1, Beit Shemesh.

Based on real cases treated at the clinic. Names have been changed.