Jaw surgery, also called orthognathic surgery, refers to the correction of the jaws by means of an operation, usually combined with orthodontic straightening of the teeth.

The word orthognathic comes from the Greek word orthos, meaning to straighten, and gnatos, meaning jaw. Orthognathic surgery thus means "Surgery to create straight jaws".

In jaw surgery, the aim is to to achieve proper occlusion (the manner in which teeth of the upper and lower jaw fit on each other) and an aesthetically pleasing face.

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.

Jaw surgery procedures are divided into three categories: maxillary surgery, mandibular surgery, and bimaxillary procedures.

BEFORE	AFTER

Indications for orthognatic jaw surgery

Situations that lend themselves to orthognatic surgery are:

1. Open bite (Apertognathia)

An open bite is a situation when the back teeth meet but the front teeth do not touch. This space causes difficulty in biting with the front teeth.

Before correction of an open bite. The shaded area is removed.		After correction of an open bite. The upper jaw is secured in proper position with plates and screws.

2. Protruding lower jaw (Prognathia)

This is a situation where the lower jaw is too large and grows too far forward. Surgery can be used to slide the lower jaw back.

Before correction of the protruding lower jaw. Lower jaw moved back for proper alignment.		After correction of a protruding lower jaw. Teeth now properly aligned and facial features normal.

Before correction of the protruding lower jaw.		Before correction of the protruding lower jaw.

3. Receding lower jaw (Retrognatia)

This is a situation where there is a "severe" overbite. These situations are managed with surgery and orthodontics together.

Before correction of a receding lower jaw. Both lower jaw and chin must be advanced.		After correction of a receding lower jaw. Teeth now properly aligned and "weak chin" corrected.

Before correction receding jaw		After correction receding jaw

4. Gummy smile (Vertical Maxillary Excess)

In this case the upper jaw has grown too far down. Surgery can move the jaw upward to create a much nicer looking smile.

Gummismile before		Gummismile After

Aesthetic rules

While tastes do differ, there is such a thing as good taste. In plastic (aesthetic) surgery, a number of guidelines have been set up describing what an aesthetically pleasing face should look like. It has to be noted that there are quite a few cultural differences in this area.

Dimensional proportions of a beautiful face

Planning

Planning for the surgery usually involves input from a multidisciplinary team. Involved professionals are Oral and Maxillofacial surgeons, Orthodontists, and sometimes a Speech and language therapist.

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.

Maxilim software

By Medicim in Belgium a new software has been developed called Maxilim that we prefer to use in all our orthognatic procedures. A CT-scan of the patient's head and a standard series of pictures has to be made. Using the Maxilim software we can cut the bones and move the jaws and chin inside the computer as planned and show the result to the patient. Small corrections can be done in the computer during the consultation. If the patient likes the result we send these data to Belgium. After a week we receive a set of acrylic templates that enable us to move the bones during surgery exactly the same as we did before in the computer.

Procedure

Prior to the operation, 2 tooth arcs must be created using orthodontic techniques which will then be located and fixed into place properly during the operation.

In order to achieve this result, we can make cuts in the bone at the locations shown in the first picture, realign the pieces as necessary, and fix them in place with mending plates and screws.

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.

As a rule, the mending plates and screws may be left in place after this period. Sometimes they will need to be surgically removed because they bother the patient.

After about 6 weeks, the bone pieces will have grown together in their new positions. Until that time, the patient will have to subsist on soft foods, as he or she otherwise runs the risk that the bone pieces will not grow together properly.

Other than moving bones around as described, bone or other materials (synthetic bone, donor bone, Gore-Tex) may be applied subdermaly in the facial area. Synthetic and donor bone will in time be transformed into own bone, and Gore-Tex will be encapsulated. In some cases, bone will be removed, a rhinoplasty be done, fat be sucked away (liposuction), etc. in order to achieve an aesthetically satisfying result.

Recovery

Immediately following the operation, the patient's face will be seriously swollen and blue. The corners of the mouth will feel stretched, the mouth can only be opened a small amount, there are a number of numb spots (particularly on the lower lip), but the amount of pain is usually surprisingly limited. The first two weeks are a very unpleasant time for the patient. Eating is difficult, and some patients have trouble sleeping. It is not uncommon for the patient to wonder if he/she made the right decision in having the operation, and they generally remain indoors. After about 2 weeks, however, patients have recovered sufficiently to take part in normal social activities. Full recovery can take up to half a year.

In general, the patient can return home the day following the operation. The first outpatient check takes place after 1 week. After the third and sixth week another checkup takes place. After about half a year, once the orthodontist has completed treatment, final photographs and x-rays are made and the patient is, in principal, done with the treatment.

Transpalatal distraction

If the upper jaw is clearly too narrow, it may sometimes be necessary to use transpalatal distractor (TPD) to widen the upper jaw. This means an additional operation. A special turnbuckle has been developed that helps separate the two halves of a surgically split upper jaw.

The turnbuckle is set against the hard palate, and has the important advantage that it does not bother or barely bothers the patient (see www.titamed.be ).