Thumb sucking is a behavior found in humans. It usually involves placing the thumb into the mouth and repeating sucking contact for a prolonged duration. As a child develops the habit, it will usually develop a “favorite” finger to suck on Thumb sucking generally stops by the age of 5 years. Some children will retain this habit, which can cause them severe dental problems. Prolonged thumb sucking can results in deformation of a child’s upper dental arch, cause cross-bite, protruded teeth, and create an open bite Malocclusion however it usually corrects itself when the child stops thumb-sucking.