What is Orthognathics
Orthognathic surgery is surgery to correct conditions of the jaw and face related to structure, growth, sleep aponea, TMJ disorders, malocclusion problems owing to skeletal disharmonies, or other orthodontic problems that cannot be easily treated with braces. It is also used in treatment of congenital conditions like cleft palate.
Bones can be cut and re-aligned, then held in place with either screws or plates and screws. Orthognathic surgery can also be referred to as Corrective Jaw Surgery.
What does Orthognathic involve?
Orthognathic surgery is performed by our oral and maxillofacial surgeon in collaboration with our orthodontist Dr Neil Counihan. It generally includes braces before and after surgery and retainers after the final removal of braces. Orthognathic surgery is often needed after reconstruction of cleft palate or other major craniofacial anomalies. Careful coordination between the surgeon and orthodontist is essential to ensure that the teeth will fit correctly after the surgery.
What planning is involved?
Planning for the surgery involves input from our multidisciplinary team. Involved professionals include the oral and maxillofacial surgeon, orthodontists, and sometimes other specialists such as restorative dentists and speech therapists. As the surgery usually results in a noticeable change in the patient’s face a psychological assessment is occasionally required to assess patient’s need for surgery and its predicted effect on the patient.
Radiographs and photographs are taken to help in the planning and there is software to predict the shape of the patient’s face after surgery which is useful both for planning and for explaining the surgery to the patient and the patient’s family. Advanced software can allow the patient to see the predicted results of the surgery.
The main goals of orthognathic surgery are to achieve a correct bite, an aesthetic face and an enlarged airway. While correcting the bite is important, if the face is not considered the resulting bony changes might lead to an unaesthetic result. Orthognathic surgery is also available as a very successful treatment (90-100%) for obstructive sleep aponea. Great care needs to be taken during the planning phase to maximise airway patency.
How does the procedure work?
The surgery might involve one jaw or the two jaws during the same procedure. The modification is done by making cuts in the bones of the mandible and / or maxilla and repositioning the cut pieces in the desired alignment. Usually surgery is performed under general anaesthetic and using nasal tube for intubation rather than the more commonly used oral tube; this is to allow wiring the teeth together during surgery. The surgery often does not involve cutting the skin, and instead, the surgeon is often able to go through the inside of the mouth.
Cutting the bone is called osteotomy and in case of performing the surgery on the two jaws at the same time it is called a bi-maxillary osteotomy (two jaws bone cutting) or a maxillomandibular advancement. The bone cutting is traditionally done using special electrical saws and burs, and manual chisels. Recently a machine that can make the bone cuts using ultra-sound waves has been introduced; this is yet to be used on a wide scale. The maxilla can be adjusted using a “Lefort I” level osteotomy (most common). Sometimes the midface can be mobilised as well by using a Lefort II, or Lefort III osteotomy. These techniques are utilized extensively for children suffering from certain craniofacial abnormalities such as Crouzon syndrome.
What happens post surgery?
After orthognathic surgery, patients are often required to adhere to an all-liquid diet. After time, soft food can be introduced, and then hard food. Diet is very important after the surgery, to accelerate the healing process. Weight loss due to lack of appetite and the liquid diet is common, but should be avoided if possible.
For some surgeries, pain may be minimal due to minor nerve damage and lack of feeling. Doctors will prescribe pain medication and prophylactic antibiotics to the patient. There is often a large amount of swelling around the jaw area, and in some cases bruising. Most of the swelling will disappear in the first few weeks, but some may remain for a few months.
The surgeon will see the patient for check-ups frequently, to check on the healing, check for infection, and to make sure nothing has moved. The frequency of visits will decrease over time. If the surgeon is unsatisfied with the way the bone is mending, she/he may recommend additional surgery to rectify whatever may have shifted. It is very important to avoid any chewing until the surgeon is satisfied with the healing.