Jaw surgery

Jaw surgery, also known as orthognathic (or-thog-NATH-ik) surgery, corrects irregularities of the jaw bones and realigns the jaws and teeth to improve the way they work. Making these corrections may also improve your facial appearance.

Jaw surgery may be a corrective option if you have jaw problems that can't be resolved with orthodontics alone. In most cases, you also have braces on your teeth before surgery and during recovery after surgery until healing and alignment are complete. Your orthodontist can work with your oral and jaw and face (maxillofacial) surgeon to determine your treatment plan.

Jaw surgery is appropriate after growth stops, usually around ages 14 to 16 years for females and ages 17 to 21 years for males.

Jaw surgery may help to:

• Make biting and chewing easier and improve chewing overall
• Correct problems with swallowing or speech
• Minimize excessive wear and breakdown of the teeth
• Correct bite fit or jaw closure issues, such as when the molars touch but the front teeth don't touch (open bite)
• Correct facial imbalance (asymmetry), such as small chins, underbites, overbites and crossbites
• Improve the ability of the lips to fully close comfortably
• Relieve pain caused by temporomandibular joint (TMJ) disorder and other jaw problems
• Repair facial injury or birth defects
• Provide relief for obstructive sleep apnea

Jaw surgery is generally safe when done by an experienced oral and maxillofacial surgeon, often in collaboration with an orthodontist.

Risks of surgery may include:

• Blood loss
• Infection
• Nerve injury
• Jaw fracture
• Relapse of the jaw to the original position
• Problems with bite fit and jaw joint pain
• Need for further surgery
• Need for root canal therapy on selected teeth
• Loss of a portion of the jaw

After surgery, you may experience:

• Pain and swelling
• Problems with eating that can be addressed with nutritional supplements or consultation with a dietitian
• A brief time of adjustment to a new facial appearance

In most cases, an orthodontist places braces on your teeth before surgery. Braces are usually on for 12 to18 months before surgery to level and align your teeth in preparation for surgery.

Your orthodontist and oral and maxillofacial surgeon work together to develop your treatment plan. X-rays, pictures and models of your teeth are part of the planning for your jaw surgery. Occasionally, the difference in the way teeth fit together will require either reshaping of the teeth, covering the teeth with crowns or both to complete correction.

Three-dimensional CT scanning, computer-guided treatment planning and temporary orthodontic anchoring devices may be used to help in the movement of teeth and decrease your time in braces. Sometimes these efforts completely eliminate the need for jaw surgery.

Sometimes virtual surgical planning (VSP) will be used to guide your surgeon to fit and correct the jaw segment position during the procedure for the most optimal result.

Before the procedure

Jaw surgery is performed by oral and maxillofacial surgeons. Surgery is usually done under general anesthesia. Surgery takes place in the hospital and requires a two- to four-day stay.

During the procedure

Surgery usually can be performed inside your mouth, so no facial scars show on your chin, jaw or around the mouth. However, sometimes small incisions may be required outside your mouth.

Your surgeon makes cuts in the jawbones and moves them into the correct position. Once your jaw movement is completed, tiny bone plates, screws, wires and rubber bands may be used to secure the bones into their new position. These screws — which are smaller than a bracket used for braces — become integrated into the bone structure over time.

In some cases, extra bone may be added to the jaw. Your surgeon transfers the bone from your hip, leg or rib and secures it with plates and screws. In other cases, bone may be reshaped to provide a better fit.

Jaw surgery may be performed on the upper jaw, lower jaw, chin or any combination of these.

Upper jaw (maxillary osteotomy)

Surgery on the upper jaw may be performed to correct:

• Significantly receded or protruding upper jaw
• Crossbite
• Too much or too little of the teeth showing
• Open bite
• Reduced facial growth of the middle of the face (midfacial hypoplasia)

Your surgeon cuts the bone above your teeth so that the entire top jaw — including the roof of your mouth and your upper teeth — can move as one unit. The jaw and upper teeth are moved forward until they fit properly with the lower teeth. This can be planned on a computer to determine if additional work, such as orthodontics, will be needed to help correct any remaining fit difference.

An open bite occurs when excess bone grows above the molars, causing what's normally a flat, even surface to become angled. To fix this, your surgeon shaves away or removes the excess bone.

Once the jaw is realigned, plates and screws hold the bone in its new position.

Lower jaw (mandibular osteotomy)

A mandibular osteotomy can correct:

• Receding lower jaw
• Protruding lower jaw

The surgeon makes cuts behind the molars and lengthwise down the jawbone so the front of the jaw can move as one unit. The jaw can then be moved to its new position either forward or backward. Plates and screws hold the jawbone together as it heals.

Chin surgery (genioplasty)

A genioplasty can correct a small chin (deficient chin). A small chin often accompanies a severely receded lower jaw.

Typically, surgeons can alter the jaw and restructure the chin during the same surgery. The surgeon cuts a piece of the chin bone on the front of the jaw, moves it forward, and secures it in a new position with plates and screws.

After the procedure

After surgery, your doctor will provide you with instructions. These usually include:

• What you can eat
• Oral hygiene
• Avoiding tobacco
• Avoiding strenuous activity
• Medications to control pain
• When to return to work or school, which is usually in one to three weeks

Initial jaw healing typically takes about six weeks after surgery, but complete healing can take up to 12 weeks.

After initial jaw healing — at about six weeks — your orthodontist finishes aligning your teeth with braces. The entire orthodontic process, including surgery and braces, may take several years. Once the braces are removed, retainers to hold tooth position may be used.

Correcting alignment of your jaws and teeth with jaw surgery can result in:

• Balanced appearance of your lower face
• Improved function of your teeth
• Health benefits from improved sleep, breathing, chewing and swallowing
• Improvement in speech impairments

Secondary benefits of jaw surgery may include:

• Improved appearance
• Improved self-esteem