"Surgery to create straight jaws" is the literal meaning of orthognathic surgery. Such corrections are largely achieved by osteotomies, surgical techniques by which parts of the jaw are cut to create separate fragments which can then be moved into new positions with preservation of their blood supply.

The most common indications for such procedures are the correction of facial deformity, dental appearance, eating and biting problems caused by malocclusion and speech abnormalities. The most commonly seen conditions, which can be corrected by orthognathic surgery, are prominence or lack of development of the upper or lower jaw. Vertical discrepancies, for example when there is too much or too little exposure of the upper front teeth and open bit deformities where the teeth do not meet, are also managed in this way.

When there is facial asymmetry, perhaps because one side of the face has failed to develop properly or alternatively has grown too much, orthognathic surgery may be used to correct the problem. Orthognathic surgery also has an important role to play in the management of congenital craniofacial syndromes, for example clefts of the lip and palate and other deformities of development of the face and skull.

In most cases, this is elective surgery and the informed wishes of the patient are paramount in deciding whether to carry out treatment. Except in the most severe deformities, or when there are major psychological or social problems, surgery is usually delayed until around 16 years of age when most jaw growth is complete. Although sometimes it is necessary to hold the upper and lower teeth together after surgery, to allow the osteotomies to heal, modern techniques of internal fixation using small plates and screws avoid this necessity in the overwhelming majority of cases.

In the management of these cases, the oral & maxillofacial surgeon works very closely with an orthodontist experienced in such conditions. The vast majority of orthognathic cases require a period of orthodontic treatment with fixed appliances in preparation for surgery. This can take from 1 to 2 years, and enables optimum correction of the dental occlusion as well as the appearance of the face and teeth. Following surgery, the orthodontist needs to complete the tooth positioning and this may take from as little as 3 months up to 12 months in difficult cases. When the fixed appliances are removed, a period of wearing a removable retainer for up to one year is usually necessary, this being normal practice after such orthodontic tooth movement to minimise relapse. 

Whilst this is major surgery, which carries with it the risk of significant complications, a number of factors have made orthognathic surgery very safe and thus in great demand. Prominent among these are good orthodontics, accurate pre-operative planning on models and computers, modern anaesthetic techniques and techniques of airway control, and the use of hypotensive anaesthesia to reduce blood loss. In addition, modern instrumentation provides accurate methods of cutting bone and precise and reliable methods of fixing bones, therefore avoiding intermaxillary fixation and external fixation. Good surgical technique, combined with the use of antibiotics and steroids reduces post-operative swelling to a minimum and as a result operating times and length of stay in hospital have reduced considerably.