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.