Does thumb-sucking cause buck teeth?

Monday, October 16, 2006
For some kids, sucking their thumb is a phase; for others it lasts longer. Does it really matter how long they do it for? Does sucking your thumb really lead to buckteeth, like the old warning goes?

Reporter Brooke Hanson visits dentist Dr Dragan Antolos in Lower Templestowe in Melbourne to ask him if thinks thumb-sucking is okay.

Surprisingly, he gives it a qualified thumbs-up.

"In fact, thumb-sucking is one of the earliest behaviours a child will develop," he says. "Often you'll see a child as early as 29 weeks in utero and they'll be sucking their thumb. For most kids it's quite a normal and appropriate behaviour."

Eighty percent of infants suck their thumbs in their first year of life. Most infants stop sucking their thumb before they turn two, but 40 percent of children are still sucking their thumbs at four years of age.

Young Max Proposch is three and still sucking his thumb. His mum Dale worries he's ruining his teeth.

Dr Antolos takes a look at Max's teeth.

"You can see these front teeth are being pushed forward and these lower teeth have been pushed back," he says. "They're actually crowding up a little bit because they've been pushed back so far. These front teeth — there's a space, like bucked. That's where Max's thumb sits."

This is exactly what Max's Mum didn't want to hear.

"You can see that it's a habit and the longer he does it, it's going to take more effort for him to stop later on," she frowns.

The key is for Max to quit thumb-sucking while he's still got his baby teeth. Thumb-sucking really only starts to cause problems when adult teeth are starting to replace baby teeth. That usually occurs around six years of age.

If Max can give his thumb up by age six, his mouth will automatically fix the distortion.

"Just the pressure from the lips and cheeks will tend to bring teeth back to pretty much their usual positions," Dr Antolos says. "But if it persists after six, you'll find that's when the problem can be quite entrenched."

Teenager Antoinette Jackson sucked her thumb until she was eight. Melbourne orthodontist Professor Michael Woods has been fixing the damage ever since.

He has photos of Antoinette's teeth at age eight.

"You can see the large gap that's between the top and the bottom teeth here," he says. "The thumb action is inhibiting the normal action of the front teeth so there's a large gap between those teeth."

Professor Woods first broke Antoinette's sucking habit by gluing a device inside her mouth.

"It has an expansion capacity as well as having arms that come in at the front," he explains. "It sits beautifully in behind the front teeth and acts as a deterrent to thumb-sucking.

Lucky for Antoinette, the orthodontic work paid off but saving that smile hasn't come cheap. You'll save yourself thousands of dollars if you can nip the habit in the bud before a child turns six.

Dr Antolos came up with a creative solution to do just that — he wrote a book about a thumb-sucking bear.

"So they'll really relate to the character and it just enables us to deliver a message in a subtle way," he says.

In the story, Oliver the bear works out a way to stop sucking his thumb. It's designed to help kids make up their own mind to stop sucking.

Here are a few more tips:
  • Encourage your child to stop, but don't make a fuss; that only makes them hang on to the security of their thumb even longer.
  • If your child agrees, try sewing up pyjama sleeves so they can't suck their thumbs in their sleep.
  • Switch to a dummy as early as you can. They're no better for their teeth but most kids spit the dummy long before they turn six, when the damage is done.

  • If you're not having any luck, talk to your dentist about it.

    Fast facts

    Many parents fear that thumb-sucking causes children to lisp — that as a child's tongue seeks out the gap between the front teeth, they develop a lisp. Speech pathologists say it's a myth and here's no evidence to prove that thumb-sucking either causes kids to lisp or makes it worse.

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