Sucking is a common instinct for babies and the use of a pacifier or their thumb offers a sense of safety and security, as well a way to relax. According to the American Academy of Pediatric Dentistry, the majority of children will stop using a pacifier and stop sucking their thumb on their own between the ages of two and four years of age. Prolonged thumb sucking or use of a pacifier can have dental consequences and needs be taken care of sooner, rather than later.