Orthodontics is based on expertise in the treatment of teeth that are not in normal position, correction of the upper and lower jaw/teeth relationships. Orthodontic treatment can be done at all ages, although the procedures that can be done vary. For example, in a child growing up, the misalignment of the bones can be eliminated by directing the jaw growth, whereas orthognathic surgery is needed to correct the incompatibilities of the bones in adult individuals. Orthodontic treatments are performed by an orthodontist.