Dental consequences of thumb sucking Many studies have concludedthat if a child stops sucking their thumb by the age of three, there is no harmcaused to the teeth or jaws. However, if the thumb suckingcontinues beyond that age, especially after five years old when the adult teethare erupting, dental problems may appear. Teeth can become misaligned bytilting more forward. In addition, there could be a bad relation createdbetween the upper and lower jaws.
