Should parents allow their children to suck their thumbs? What are the causes and problems involved with thumb sucking? Many doctors believe that thumb sucking will lead to an impact on a child’s teeth. Thumb sucking puts pressure on the sides of the upper jaw and the soft tissue on the roof of the mouth. The can cause the upper jaw to narrow, which means the teeth will not meet properly. This can be fixed with braces, but can also cause speech problems, such as a lisp. Thirty percent of [...]