Malocclusion of teeth is the misalignment of teeth, when the upper teeth do not fit properly with the lower, it is usually hereditary. The patient has a size difference between jaws or between jaw and tooth. Other factors that may cause malocclusion are loss of teeth, thumb sucking or pacifier use. The main symptoms are crowded or protruding teeth, which cause trouble eating and speaking. Treatment of malocclusion of teeth involves the use of fixed or removable appliances to correct the alignment of the teeth and jaw. In children and adolescents, the extraction of some teeth may also be needed. Children's malocclusion of teeth is easier to correct than in adults because bone growth is still under development. By using such apparatus the teeth straighten and the jaw moves. In adulthood you can align teeth through orthodontics, but the position of the jaws can only be changed with orthognathic surgery.