Orthodontia, also called orthodontics and dentofacial orthopedics, is a specialty of dentistry that deals with the diagnosis, prevention and correction of malpositioned teeth and jaws. Three type of appliances can be used : REMOVABLE APPLIANCES FIXED APPLIANCES FUNCTIONAL APPLIANCES Orthodontic treatment can focus on dental displacement only, or deal with the control and modification of facial growth. In the latter case it is better defined as "dentofacial orthopedics". In severe malocclusions that can be a part of craniofacial abnormality, management often requires a combination of orthodontics with headgear or reverse pull facemask and / or jaw surgery or even orthognathic surgery.