Orthognathic surgery, or corrective jaw surgery, is a procedure that corrects conditions of the jaws and the face. In orthodontics, orthognathic surgery is performed when the upper and lower jaws don't meet harmoniously to fit together. While orthodontics straightens teeth, corrective jaw surgery sections and re-aligns bones then holds them in place with screws and plates. In cases where orthognathic surgery is needed, the end result improves facial appearance and ensures that teeth function properly.
When is orthognathic surgery needed?
Jaw growth is a slow process that lasts throughout childhood and ends at the young adult age. Sometimes the upper jaw (maxillary) and lower jaw (mandible) don't grow at the same rate and the result affects chewing function, appearance, speech, and oral health.
About 5% of the European and North American population has jaw deformities where orthodontic treatment would also need orthograthic surgery as a definitive treatment. Surgery can correct:
- size and position variations that have affected one or both jaws (maxillary and mandible), among which it can be prognathism (protruding jaw), or retrognathism (retrieving jaw);
- facial and skeletal deformities associated with sleep apnea (disorder in which there are breathing pauses when a person is sleeping);
- facial and skeletal deformities related to airway defects (access by which air reaches a person's lungs);
- facial and skeletal deformities associated with temporomandibular joint disorder (TMD) (joint of the jaw with the rest of the skull);
- congenital conditions such as cleft palate or other skull or facial anomalies.
Orthognathic surgery is achieved by a dental specialist called oral and maxillofacial surgeon, in combination with an orthodontic treatment. There has to be good planning between the surgeon, the orthodontist, and sometimes the speech and language therapist, before starting the treatment. The goals are to correct the bite, improve facial aesthetic, and enlarge the breathing airways.
Usually surgery is performed under general anaesthesia and involves one or both jaws. The surgeon sections the bones of the maxilla or the mandible and repositions them in a desired place for good alignment. Cutting the skin is usually not needed as the surgeon often works from the inside of the mouth. Screws and plates hold the bones together, and usually must stay there all the time.
After surgery the jaws are attached together using stainless steel wires to ensure keeping the correct position of the bones.
Post operation healing
To minimize infection and pain, the surgeon prescribes analgesics and antibiotics. It is expected to have facial swelling for a period from a few weeks to a few months, and this depending on how complicated the surgery was.
It is very important to avoid chewing food in order for the repositioned bones to heal into place. Therefore, the patient has to go through weeks of a liquid diet, followed by a diet of soft foods, and then slowly incorporating hard foods. During this period, the patient might lose some weight because of the reduced appetite from the medication, and from the liquid foods. It is important that the liquid diet is rich and balanced to get all the needed nutrients.
Like any type of surgery, corrective jaw surgery can have complications such as swelling, bruising, prolonged bleeding, infection and nausea.
Very rarely, this type of surgery can cause nerve damage, which is followed by numbness of parts of the face. The prolonged numbness is called paresthesia, and can be either temporary, or very infrequently, permanent.
When orthognathic surgery is performed on the upper jaw, the shape of the nose can be changed. But sometimes this can be a desired part of the treatment plan.