Jaw surgery is performed for medical, reconstructive and aesthetic reasons. This article looks at the aesthetic aspects of jaw surgery, discussing the different procedures that can improve the smile and help correct facial imbalance, as well as fixing a receding chin and protruding jaw.

When jaw surgery is combined with orthodontics, it’s referred to as orthognathic surgery. In Latin this literally means to ‘straighten the jaw’. Although most often performed to facilitate better breathing, chewing and speaking by correcting misalignment in jaws and teeth, jaw surgery does not end with functional improvement. By changing the shape and proportion of the face, jaw surgery can dramatically improve a person’s appearance.

Jaw surgery can be divided into three groups:

• Upper jaw surgery or maxillary osteotomy
• Lower jaw surgery or mandibular osteotomy
• Chin surgery or genioplasty

Reasons for choosing to have jaw surgery

People with the following conditions can benefit from jaw surgery:

• Difficulty chewing, biting or swallowing food.
• Chronic pain in the jaws or jaw joint disorders (temporomandibular joint – TMJ disorders).
• Excessive wear of the teeth due to bite problems.
• An open bite (space between your upper and lower teeth when the mouth is closed).
• Injuries to the face.
• Birth defects.
• An imbalance in facial appearance from the front, or in profile.
• A receding chin, also referred to as a ‘weak chin’ (apertognathia).
• A protruding jaw.
• Inability to make the lips meet without straining.
• Chronic mouth breathing, often accompanied by dry mouth.
• Sleep apnea.
• When the lips fail to close naturally or pull upwards when smiling, exposing a large area of the gums (gummy smile).
• Toothless smile, where lips cover all of the teeth when smiling.

Some of the above issues—such as a receding chin, protruding jaw or facial imbalance, gummy or toothless smile—involve jaw surgery for purely aesthetic reasons, but functional issues can often be corrected at the same time. In the same way, procedures that are primarily undertaken to improve functionality can also bring about aesthetic improvements. Typically, when planning orthognathic surgery, your oral and maxillofacial surgeon will take both functional and cosmetic aspects into consideration. Often the surgeon works closely with your orthodontist to coordinate treatment plans.

Jaw surgery is only recommended for people who have reached a certain level of growth. Females typically reach this stage by the time they are 14 or 15 years of age. Males take a bit longer, reaching this stage between the ages 17 and 21. There are a few exceptions to this rule, including correction of cleft lip and other birth defects in infants and treatments for traumatic injury.

What to expect

Most people who need jaw surgery are referred to an oral and maxillofacial surgeon by their orthodontist or, in the case of birth defects, injuries or sleep apnea, by their doctor or consultant. In certain cases, a speech therapist may also be involved.

Expect to undergo multiple tests and examinations, including X-ray, other imaging and a psychological evaluation in preparation for the procedure.

Jaw surgery is performed entirely with incisions made inside the mouth, leaving no external scars on the chin, jaw or around the mouth. If your surgeon uses dissolvable sutures, they will dissolve over time. Non-dissolvable sutures will be removed after five to seven days.

Jaw surgery can be performed for a number of reasons:

• To move the lower jaw forward or backwards, to either shorten or lengthen it.
• To move the upper jaw in various directions to correct irregularities.
• To move the chin forward or backwards, upwards or downwards.

Upper jaw surgery or maxillary osteotomy primarily treats problems such as underbite, overbite, cross bite and open bite. It can also be performed to correct an excess or deficiency in upper jaw height, which results in showing of too much or too little teeth.

During upper jaw surgery, the jawbone is cut just beneath the eye sockets and moved forward as one piece—containing the top jaw, upper teeth and roof of the mouth. Once the upper teeth are aligned with the lower teeth, tiny metal screws fix the jaw in its new position. These screws are much smaller than brackets used in braces. Over time they become integrated into the natural bone structure.

In those who have an open bite, the surgeon will shave away excess bone to reduce the jaw height, thus removing the gap between the upper and lower teeth.

Lower jaw surgery or mandibular osteotomy corrects deficient or a receded lower jaw (apertognathia) or a large lower jaw. During lower jaw surgery the surgeon makes a cut in the bone just behind the back molars as well as lengthwise along the jawbone to enable movement to the front of the jaw. Once the lower part of the jaw has been moved to its new position, screws are used to hold the bone in place.

Chin surgery or genioplasty is also referred to as interior border osteotomy. This procedure corrects a deficient or receded chin by moving the chin bone upwards to make it shorter or downwards to make it longer. Chin bones may also need to be moved backwards or forwards to enable the patient’s lips to touch in a natural position. Often chin abnormalities are accompanied by a receded bottom jaw. This is why surgeons typically perform the two procedures together.

In some types of surgeries, bone grafts are required to make the correction. In such cases, bone is taken from the hip, leg or the ribs and secured in place with temporary wires. The body’s natural healing process then secures it in its new location.

Jaw surgery usually requires a hospital stay of one to three days depending on your progress and the exact procedure. Expect your recovery period to be anywhere between three to six weeks. Most of the healing takes place in the first two months. You may need to stay at home for two to four weeks following surgery.

You will not be able to see the final outcome of the operation for several months, because it takes time for the shape of your face to adjust.

Before and after surgery

If jaw surgery is required for solving bite issues and other orthodontic problems, you may need to undergo an orthodontic treatment in preparation for jaw surgery. Pre-surgical orthodontics ensures that all possible corrections are made before you have surgery.

You may need to wear braces for 6 to 18 months before surgery, depending on the type of corrections you need. Fitting braces will begin the change that ends with the jaw surgery. During surgery, pins inserted through a slot in your braces are used to secure your teeth. A strong arch wire that is heavy enough to withstand surgery will be fitted before you have your surgery. Orthodontic treatment will also involve taking impressions to check the progress of your orthodontic alignment. Your surgery will be scheduled once your surgeon and orthodontist are satisfied about achieving the pre-surgical goals.

You will be expected to wear your braces after surgery for some time, usually 6 to 12 months from the surgery date.

Once your jaw heals sufficiently—approximately six weeks from the date of surgery—the alignment is likely to be completed. At this point, your orthodontist will remove the braces. Most patients have a fixed retainer permanently bonded inside their lower front teeth before braces are removed. The upper retainer is usually removable and will be fitted within one week from when the braces are removed. You will only have to wear this for a limited period. Your oral and maxillofacial surgeon and orthodontist can explain why you need a retainer and for how long you are expected to wear it.

The entire process, including pre-surgical orthodontics, surgery and follow up may last from one to two and a half years.

Besides the specific preparations involved in jaw surgery, there are several things you can do to prepare for any surgery.

There will be numbness and swelling after the surgery. Pain is usually a lesser issue, but you will be given pain medications to help manage it before you leave hospital. Swelling may seem worse than it is because your lips will feel numb. Swelling will gradually subside over 2 weeks. You may have difficulty speaking during this period.

Facial bruising is quite normal after surgery, and in many cases appears about a week after surgery. Bruising may occur on the sides of the face, upper neck area and under the eyes.

It may be difficult to breathe through your nose due to congestion. Some people find it uncomfortable to breathe through their mouth as well. Some develop a sore throat after surgery. Using a humidifier and keeping a wet washcloth to moisten your lips will help prevent them from drying out. You may also try placing a wet cloth on your mouth, preventing excessive dryness by breathing through it. It is important to keep yourself well hydrated during this time. Using a sippy cup with a straw is a good idea.

Most people who undergo jaw begin to feel better after about a week. Younger patients find it easier to recover and may recover faster than older patients.

In some cases, your mouth will be wired shut. Even if not, your jaws will take some time to heal and strengthen after surgery. Eating will be a problem during this period. How you manage this will be a key factor in your recovery. You will need to manage for at least four weeks post surgery on a diet of liquefied food. A dietician can help you plan your meals for this period before you leave hospital. Your surgeon will advise you when you can gradually move on to semi-solid and solid foods. For most people, this is four weeks after surgery. Most people can’t stay on a liquid diet for a month and maintain their current weight, so expect to lose some weight.

Although you may feel uncomfortable when you speak, you need to do it anyway. Talking will help strengthen your jaws and muscles.

There are general steps that can speed up the healing process after surgery. Follow these and your surgeon’s instructions carefully to ensure speedy healing and a good outcome.

Possible risks and complications

As with any surgical procedure there are risks involved in jaw surgery. You should be fully aware of potential risks and complications involved in any surgical procedure before you elect to go through with it.

Specific complications that may occur during or after jaw surgery include:

• Injury to nerves and resulting numbness – Because many nerves crisscross the face and neck, surgery may result in damaging some nerves. In particular, the trigeminal nerve and the lingual nerve may be at risk.

Because the trigeminal nerve is disturbed during surgery, your lips will be numb after the operation, similar to when a dentist has given you an injection of local anaesthetic. Usually the upper lip recovers quickly, but the lower lip may take six to nine months to get back to normal. During this time your lips will look and move in the normal way. Only you will be aware of the numbness and nobody will be able to tell. In very rare cases numbness is permanent. Upper jaw surgery may also result in some numbness near the gum line, around the teeth and upper jaw.

Although uncommon, lower jaw surgery can affect the lingual nerve, which plays a role in sensations of the tongue. Stretching or bruising of this nerve during surgery can affect your tongue and its sensory abilities.

• Infection – The tiny screws and fixing plates are usually left inside your jaws permanently. In about ten per cent of cases they may need to be removed due to infection, but usually by that time they have already served their purpose.
• Need to readjust the bite – In very rare cases it may become necessary to readjust the bite. This can occur as a patient wakes up from the relaxed state induced by anaesthesia and their strong jaw muscles move the bite. Even a movement of a few millimetres can involve the need for a second operation.
• Jaw joint (TMJ) disorders – People who are diagnosed with TMJ disorders will be treated for it before jaw surgery. However, in some cases the dysfunction of the jaw joint may not be apparent. In a few rare cases, such problems may become worse as a result of jaw surgery.

Just as you would discuss potential benefits before surgery, it is always advisable to ask your surgeon to address the potential risks as they apply to you. Your orthodontist and surgeon can also advise you on how to avoid or minimise some types of risk.

Rough costs involved

The cost of jaw surgery will vary depending on the surgeon you choose, the facilities used and the exact procedure that must be performed. Your surgeon will help you estimate potential costs after a consultation.

Although many of the costs involved in jaw surgery are partly covered by Medicare and private medical funds, expect there to be a gap between your actual costs and reimbursements. Some Australian private health insurers may help pay for the hospital bed and theatre fees even if the procedure is not covered.

This information is correct as of 2019.