Orthognathic surgery, corrective jaw surgery, is used to treat facial and jaw abnormalities in which the facial bones and teeth are not correctly developed. This results in difficulty with chewing, speech, and jaw function. In many cases, the facial appearance is affected by the developmental abnormalities. Orthognathic surgery corrects these jaw and facial deformities, usually in conjunction with an orthodontist. Once the jaws are corrected teeth will come together properly.
The initial surgical consultation involves a careful examination by the surgeon, including photographs and radiographs used to individualize each patient’s treatment. We utilize the latest in digital imaging technology which allows for computerized treatment planning and visualization of post-operative changes to the facial appearance. This helps the corrective jaw surgery patient understand both the functional and aesthetic benefits of the procedure.
The two most commonly performed operations are the sagittal split osteotomy of the mandible, or lower jaw, and the Le Fort I osteotomy of the upper jaw. Surgery may include procedures to the chin, cheeks, eyes, nose, neck and facial skin in conjunction with the corrective jaw surgery in order to further enhance facial appearance. Prior to corrective jaw surgery close consultation with an orthodontist is important as the patient may require a period of pre-surgical and post-surgical orthodontics that lasts six to 12 months.
Sagittal split osteotomy (lower jaw)
The sagittal split osteotomy of the lower jaw is done through incisions placed inside the mouth, near the back part of the cheek where it attaches to the lower jaw. The jaw bone is divided in the area of the angle of the jaw in a front-to-back plane. This allows the tooth-bearing part of the lower jaw to slide backwards, in the case of a protruding lower jaw, or forward in the case of a deficient or short lower jaw.
In the past, thin wires were used to support the bones in the new positions but because this was not stable the patient also had to endure periods of six to 12 weeks of “maxillomandibular fixation,” or having their teeth and jaws wired together after corrective jaw surgery. Not only was this uncomfortable but oral hygiene was difficult and post-operative weight loss was a problem. Fortunately, small titanium screws have been developed that are placed to hold the segments together during healing and the jaws need to be rubber-banded together for only about one week.
Le Fort 1 osteotomy (upper jaw)
The Le Fort I osteotomy of the upper jaw is performed through incisions placed inside the mouth, inside the upper lip. A horizontal transection of the upper jaws’ attachment to the base of the nose and sinuses is performed and the upper jaw can then be moved in the direction necessary for correction of the bite and facial problem. Like the sagittal split osteotomy, the repositioned upper jaw is maintained in position with tiny plates and screws made of titanium, a metal to which bone loves to bond. Rubber bands are used to keep the jaws together for about a week and patients are placed on a soft diet for approximately five weeks.