Age 7 Is the Minimum, Not the Target. Here’s Why, and the Nickel Test You Can Do Tonight
The American Association of Orthodontists is clear on this one: every child should
have an orthodontic evaluation by age 7. It’s not a soft suggestion. The AAO
has run public awareness campaigns around this exact number for years, because by
age 7, enough permanent teeth and jaw structure are in place to catch real
developmental problems while there’s still time to act.
Here’s what we want parents to understand: age 7 is the minimum, not the
target. Our protocol recommends evaluation by age 4 or 5, two to three years
earlier than the AAO’s floor.
Why the AAO says 7
By age 7, a trained eye can usually spot the early signs of several developmental
issues:
- A top jaw that’s grown too far forward, or a bottom jaw that’s recessed
- A crossbite, where the upper and lower teeth don’t meet the way they should
- A front tooth taking repeated direct impact because of how the bite closes
Left unaddressed, these aren’t just cosmetic. They can mean permanent tooth damage
and jaw problems that get harder, and more expensive, to correct the longer they
go unaddressed. Seven is the AAO’s line in the sand because that’s the latest point
most of these issues are still straightforward to catch and manage.
Why we go earlier
Waiting until 7 means waiting until after a meaningful amount of the growth window
has already passed. By going earlier, age 4 to 5, we’re often able to catch and
guide developmental issues while there’s more growth left to work with, which
generally means simpler treatment and better outcomes than correcting the same
problem later.
What the AAO says about sleep and airways
The AAO’s white paper on this topic, “Sleep-disordered breathing and orthodontics: An American Association of Orthodontists white paper update” (2026), guides orthodontists on their role in managing obstructive sleep apnea. It is cautious about what orthodontic treatment can claim, and we respect that caution. Our role is to screen, to refer for a sleep study when the signs call for it, and to work alongside your child’s physicians. Early evaluation is how we spot a narrow jaw while there is still growth to work with.
The nickel test
Here’s something you can actually check tonight, and it’s one of the clearest
“good sign vs. bad sign” tests we know.
At around age 5, you should be able to slide a nickel between every tooth across
the front of your child’s mouth.
That sounds backwards. Gaps between baby teeth look alarming to most parents. But
here’s why it’s actually a good sign: adult teeth are bigger than the baby teeth
they replace, especially the front six. (The one exception happens only in the very back of the mouth, where adult teeth
are slightly smaller than their baby counterparts, and only mildly.) Because the incoming adult teeth need significantly more horizontal
room than the baby teeth currently take up, that extra space has to already exist
before any teeth are lost. If it’s not there in advance, it’s not going to
magically appear once the adult teeth start coming in. They’ll crowd instead.
So: spacing in a young child’s front baby teeth is a good sign, not something to
worry about. The absence of spacing (teeth that look tightly packed and “perfect”
at age 5) is actually the early warning sign of crowding to come.
A panoramic X-ray or CBCT makes this visible directly. It’s one of the best pieces
of education we can show parents: literally seeing, on the scan, how much room their
child’s jaw currently has for the teeth that are on their way in.
What to do with this
If your child is approaching age 4 or 5, this is a good time for a first look,
well ahead of the AAO’s age-7 floor, and while there’s maximum runway for simple,
growth-guided solutions if something needs attention. If your child is already past
5 and you’re not sure where things stand, there’s no harm in checking now.
Take the first step
👉 Take the 60-second airway screening →
Or call to schedule an evaluation:
Northridge: (818) 341-5150 · Newbury Park: (805) 498-7785
Medical disclaimer: This article is educational and is not medical or dental advice,
diagnosis, or treatment. Individual growth and development vary; an evaluation is the
only way to know where a specific child stands. Medically reviewed by Dr. Yoram
Kohanzadeh, DDS, orthodontist, Smile By Dr. K, Northridge & Newbury Park, CA.