Orthodontics, << `awr` thuh DON tihks, >> is the branch of dentistry that prevents and corrects irregular positions of the teeth. In addition to causing poor personal appearance, irregularly positioned teeth are difficult to clean. Thus, they are more likely to decay and promote gum diseases. See Teeth (Periodontal diseases). Irregularly positioned teeth also can cause chewing and speech problems and can damage the jaw.
Irregularities in the position of teeth are called malocclusions. Malocclusions usually arise during childhood as the teeth grow. They most commonly occur when the teeth are too large for the available jaw space. Under such conditions, the teeth become crowded and turned out of position. In some cases, one of the jawbones is larger than the other, creating either an overbite or an underbite.
Malocclusions can sometimes be prevented by the early removal of certain deciduous teeth (baby teeth). This process, called serial extraction or guidance eruption, relieves crowding that occurs as new teeth break through the gums. If the teeth are already out of position, orthodontists cement metal or plastic braces to the front of each tooth and connect the braces with wires. By gradually tightening the wires, they move the teeth into proper position. In some cases, a tooth is extracted so that other teeth can be moved into its place. Orthodontic treatment is sometimes combined with surgery on the jawbones to correct malocclusions.
Orthodontic treatment is typically begun when patients are 10 to 16 years old and lasts about two years. Many adults also undergo orthodontic treatment, but treatment time is generally longer.
See also Teeth (Malocclusion).
