Common concerns about school-age children’s teeth include teeth-grinding, thumb-sucking and teeth injuries like knocking out teeth. If your child plays sport, it might be time to think about a mouth guard.
Thumb-sucking
Most children grow out of the habit of sucking thumbs and fingers from 2-4 years of age.
You can usually reverse the effects of thumb-sucking up to 5-6 years, because children still have their baby teeth. If children are still sucking after this age, dental problems can come up.
Vigorous finger-sucking (that’s when you hear a popping sound when a child takes thumb or fingers out of his mouth) and sucking that goes on over many years can affect the growth of a child’s jaws and the way his teeth line up. If you’re concerned about your child’s sucking habits, talk to your dentist.
Source: http://raisingchildren.net.au/articles/teeth_issues_school_age.html
