Thumbsucking is a common, comforting habit that most kids take up at some point in their early years. However, if your child is a regular thumbsucker, you may be wondering about the habit’s potential to harm developing teeth. Although thumbsucking is generally nothing to worry about, it’s important to be aware of the dental problems the habit can cause, especially when it crosses over from typical behavior to something you should bring up to your pediatrician or dentist. When to Consult Your Provider About Thumbsucking The way your child sucks on his thumb can make it more or less likely that the habit will cause dental problems. If your child is a passive sucker—meaning she gently rests her thumb in her mouth and inactively sucks on it—the habit is less likely to create tooth problems down the road. If your child is an active sucker, it's more likely he’ll develop dental problems. You’ll know your child is an active thumbsucker if, when he removes his thumb from his mouth, you hear a popping noise, and if you notice him sucking more vigorously in general. Regular active thumbsucking can cause problems in your child’s teeth alignment. If your little one is an active sucker, you’ll want to be sure he kicks the habit within a typical timeframe, which is usually by around age 4. If the habit persists beyond this, or if you’re not sensing it’s close to fading as age 4 approaches, it’s smart to check in with your pediatrician or dentist, as the risk of damage to your child’s permanent, adult teeth becomes more likely at this point. The Negative Effects of Thumbsucking on Children’s Teeth Children who suck their thumbs are more likely to have dental problems, since the habit can affect how teeth come in and how they line up. The most common dental issue thumbsucking causes is what’s known as an anterior open bite—an opening between the top and bottom front teeth that remains even when your child’s back teeth are closed. This happens because, instead of your child’s front teeth lining up in a neat top-over-bottom fashion, they form around that spot where the thumb is often resting, creating a gap between those top and bottom teeth. Thumbsucking can also push kids’ teeth forward as they come in through the gums, causing problems in teeth alignment. Once the teeth come in this way, correcting them can be time-consuming, uncomfortable and expensive, which is why it’s important to stop the habit before permanent teeth start coming in. In addition to affecting the alignment and growth of your child’s teeth, prolonged thumbsucking can affect other aspects of your child’s mouth. As kids develop that gap between the top and bottom front teeth, this can encourage the development of a tongue thrust—an incorrect way of swallowing that reinforces the gap, which also takes intensive intervention, usually in the form of therapy, to correct. Moving Forward Remember that thumbsucking before age 4 is completely normal, with the habit usually starting to decrease around age 2, and that most children quit on their own before kindergarten. If your 4-year-old is still sucking vigorously, or if you notice issues in the alignment of his or her teeth, check with your pediatrician or dentist about positive strategies for helping your child stop thumbsucking. Particular types of negative parental pressure have been shown to do more harm than good, and your provider can point you toward simple, supportive techniques that will help your child kick the habit.