Is thumb-sucking harmful?
Thumb-Sucking Is Safe for Young Children
It's perfectly normal for young children to suck their thumbs, even though some parents fret about it. The habit is typically harmless if children do it occasionally, such as while being tucked in at bedtime or in association with a stressful event.
When It's a Problem
Most children will stop thumb sucking between ages 2 and 4. Older children who chronically suck their thumbs or fingers may need guidance from parents or a dentist to stop the habit. That's because the chronic sucking habit can cause children's permanent teeth to become crooked.
If you're in doubt, discuss the matter with your dentist or pediatrician. You may be reassured to learn that if your children are tapering off thumb sucking, there is probably no need for treatment. That's particularly true if they still have baby teeth. Dental problems are usually avoided if the habit stops before the permanent teeth erupt.
Oftentimes children themselves will want help to stop. It has to do with social acceptance, especially at school.
How to Break the Habit
If you think your children have a problem, you might want to deal with the habit initially by ignoring the behavior. In other words, don't give them attention when they suck their thumbs. Put an obstacle on your children's hands. You might try a sock or a glove.
Another idea: Provide rewards for positive behavior. Praise your children whenever you notice that they are not sucking their thumbs. You also might mark a star on a calendar when they go without thumb sucking for a day or leave their socks or gloves on all night. Stars could earn an extra story, a trip to the library, or some other reward.
Your dentist or pediatrician can also give you advice about how you can gradually phase out the use of these methods to keep the habit from returning. In some cases, use of a device for inside the child's mouth may be recommended to make thumb sucking more uncomfortable.
Sources:
“Thumbsucking.” Mouth Healthy, American Dental Association. www.mouthhealthy.org/en/az-topics/t/thumbsucking Accessed 2013.
“Thumb, Finger, and Pacifier Habits.” American Academy of Pediatric Dentistry. http://d27vj430nutdmd.cloudfront.net/17255/64422/64422.3.pdf Accessed 2013.
“Frequently Asked Questions: Are Thumb Sucking and Pacifier Habits Harmful To A Child's Teeth?” American Academy of Pediatrics. www.mychildrensteeth.org/education/faq/#24 Accessed 2013.
“Straight Talk on Braces.” Federal Citizens Information Center http://publications.usa.gov/USAPubs.php?PubID=6055. Accessed 2013.