An overbite occurs when the upper jaw is longer than the lower jaw. An underbite occurs when the lower jaw is longer than the upper jaw. Overbites and underbites don’t always cause problems. Yet, even if your child doesn’t suffer from a speech impediment or sinus problems they may be subject to teasing from other children. Early orthodontic treatment involves taking x-rays and a mold to determine the cause of the misplaced bite. Then, treatment is customized for each child.