There is no need to worry about your child’s thumb-sucking habit during their pre-school years, however, if they have not stopped by the time that the permanent teeth come in, then life long damage can occur. Many times, peer pressure in school alone can cause a child to stop the habit. However, an occasional child will still persist, especially at night while sleeping. Many methods have been proposed and tried to break the habit. No one technique works for every child. There are positive and negative ways. Using positive reinforcement can be very effective but requires a lot of work. You can get a calendar and stick a star on for everyday that the child doesn’t suck their thumb. So many days in a row can earn a reward. This requires lots of parental participation and is difficult to break nighttime sucking. Other methods include wrapping the thumb in tape or gauze or placing a sock over it while sleeping.
By not stopping a thumb-sucking habit by the time that the permanent teeth erupt, the child will not swallow properly. This causes a dreadful muscle imbalance which affects the direction and growth of the jaw bones and the final placement of the teeth. The upper arch tends to be long and narrow since the tongue tends to thrust forward with each swallow. The lower jaw will tend to be smaller because the tongue will usually be swallowing forward. Once the thumb-sucking habit is stopped, the orthodontic problems persist since the muscles are in imbalance. When orthodontic treatment is done, the muscle imbalance and swallowing issues must be addressed or else rapid relapse can occur. Things such as myofunctional therapy or tongue exercises are best instituted before any orthodontics is started. This will allow for a much more stable result.