Thumb sucking changes the structures of the mouth and can negatively influence facial growth and development.
The number 1 reason children suck is nourishment. For example if you stroke a baby’s chin you see the instinctive response immediately. Sucking produces endorphins, a natural-occurring chemical in our brain, which produces pleasure? With these early positive associations and pleasurable experiences they soon transfer this sucking action to other items.
Sucking becomes a habit because children find sucking can stave off boredom and they often use this as a means of soothing distress, illness or fatigue. Thumb sucking starts very early. Babies have been documented on sonograms in the utero already beginning to thumb suck.
When should parents become concerned? 
Between the age of 4 and just prior to the eruption of the permanent teeth is when much of the damage that occurs to the palatal structure can be reversed. If sucking continues past the age of 4, prolonged and vigorous sucking can alter normal growth and development of the skeletal bones, facial muscle and the nasal cavity. In thumb suckers, the roof of the mouth grows vertically instead of horizontally, narrow and becomes vaulted, often taking on the shape of the thumb or finger. If the palate is narrow, the nasal cavity and sinus may also develop with a narrow and shallow anatomy. Thumb sucking can also affect tooth alignment, lip structure, tooth eruption, finger growth, speech, breathing and swallowing functions.
The more vigorous and prolonged the sucking habit and the more fingers sucked, the greater the degree of damage. Two-finger sucking is considered the most damaging and a thumb sucker who hooks the index finger above the nose will develop finger, nasal and palatal damage simultaneously. 
About 33 to 50 percent of 3 to 5 year olds suck fingers and thumbs when they are tired. Approximately 13 percent of children entering kindergarten suck a finger or thumb, and for 7 to 11 year olds it is about 6 percent, with more thumb or finger sucking occurring at night.
80% to 90% of suckers will require some type of orthodontic treatment after the habit has stopped. If a tongue thrust has developed as a result of prolonged thumb sucking, this needs to be eliminated through exercises designed to retrain, improve and correct muscle patterns.
Dr. Timothy Isaacson is available to discuss any concerns you may have regarding your child’s thumb sucking habits.
For more information visit: www.iaom.com
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