Jaw Surgery

WHO IT IS FOR

Jaw surgery is considered where a discrepancy between the jaws is too great for orthodontics alone to correct, and where it is causing functional problems, aesthetic concern, or both.

The situations most often involved are:

A lower jaw that sits too far back, so the upper front teeth project well ahead of the lower ones and the chin appears set back.

A lower jaw that sits too far forward, producing an underbite where the lower teeth close in front of the upper ones.

An open bite, where the front teeth do not meet at all when the back teeth are closed, so biting through food at the front is difficult.

A significant asymmetry, where one side of the jaw has grown differently from the other.

An upper jaw that is too long or too short vertically, which affects how much tooth and gum shows and the proportions of the lower face.

A narrow upper jaw, which may require widening.

Surgery may also form part of the treatment of obstructive sleep apnoea in selected cases, and of certain congenital conditions and injuries.

 

WHAT IT ACHIEVES

Function first. A corrected bite distributes chewing load evenly, which matters for the long-term health of the teeth and the jaw joints. Patients commonly report that eating becomes easier and that teeth stop wearing unevenly. Speech can improve where the bite was interfering with it.

Appearance follows. Because the jaws determine the shape of the lower face, repositioning them changes the profile — the chin, the lips and their relationship to the nose and cheeks. For many patients this is a significant part of the motivation, and there is nothing wrong with that, but the planning is driven by function and the facial change follows from it.

Breathing, in cases where the airway is affected by jaw position.

 

THE PROCESS

Orthognathic treatment is a planned sequence that usually takes place over one to two years, and the surgery itself is one step within it.

Assessment and planning. Photographs, X-rays, a three-dimensional scan and models or digital scans of the teeth. The movement required is planned precisely, now very often with digital planning software that simulates the result before anything is done.

Orthodontics before surgery. In most cases braces are fitted first, for a period of months, to align the teeth within each jaw and to position them so that they will meet correctly once the jaws are moved. This phase can temporarily make the bite look worse, because the teeth are being moved out of the compensated position they had adopted. This is expected and is explained beforehand.

The surgery. Carried out under general anaesthesia, in a hospital, by a maxillofacial surgeon, usually with a hospital stay of a night or two. The incisions are made inside the mouth in most procedures, so there are generally no visible scars on the face. The bone is divided, repositioned according to the plan and fixed in its new position with small titanium plates and screws, which usually stay in place permanently.

Recovery. Swelling is considerable in the first week and reduces over the following weeks, with the final settling taking several months. Modern fixation usually means the jaws are not wired shut, but a soft or liquid diet is required for a period, and elastics may be worn between the teeth to guide the bite.

Orthodontics after surgery. A further period of braces to finish the bite precisely, followed by retainers.

 

WHAT TO EXPECT IN RECOVERY

The first week is the most demanding. Swelling peaks in the first few days, eating is limited to liquids or soft food, and speech is affected by the swelling. Numbness of the lip, chin or cheek is usual at first as nerves recover from being stretched; this resolves over weeks to months in the great majority of patients, though in a small number some altered sensation persists.

Most people are back to desk work within two to four weeks, depending on the procedure, and to normal diet and activity over the following months.

Follow-up appointments are frequent in the early period and continue throughout the orthodontic phase.

 

RISKS AND LIMITATIONS

Orthognathic surgery is a major, well-established procedure, but it is major surgery and the risks should be understood before consenting to it.

These include the general risks of surgery and general anaesthesia; altered or reduced sensation in the lip, chin or tongue, which is common early and occasionally long-lasting; infection; bleeding; the need for plates to be removed in a minority of cases; relapse, where some of the correction is lost over time; and effects on the jaw joints, which can improve or occasionally worsen.

The result is also a change to your face, and it is a permanent one. Digital planning gives a good indication of the outcome but it is a prediction, not a guarantee, and soft tissue does not always follow bone exactly.

These are reasons for careful assessment and a properly informed decision, not reasons to avoid treatment where it is genuinely indicated.

 

HOW IT DIFFERS FROM OTHER TREATMENTS

Orthodontics alone can correct many bite problems where the jaws themselves are in a reasonable relationship. Where the discrepancy is skeletal and significant, orthodontics can only disguise it by tipping teeth, which has limits and can create other problems.

Cosmetic treatment of the teeth — crowns, veneers — changes the appearance of the teeth but does nothing to the jaws, and is not a substitute where the underlying issue is skeletal.

Chin surgery (genioplasty) repositions the chin point alone. It is sometimes carried out with jaw surgery and sometimes on its own, where the chin is the only element out of proportion.

Which of these applies is determined by examination and by measurements taken from the scans, not by appearance alone.

 

QUESTIONS PATIENTS ASK

Will I have scars on my face? Most orthognathic procedures are carried out entirely through incisions inside the mouth, so there are no visible facial scars. Some specific procedures require small external incisions.

 

Will my jaws be wired shut? In most modern cases no. Plates and screws hold the bone in position, and elastics are used to guide the bite rather than to immobilise the jaws.

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How long is the hospital stay? Usually a night or two, though this depends on the procedure and the individual.

 

Do I have to have braces as well? In the great majority of cases yes, both before and after surgery. The surgery positions the jaws; the orthodontics positions the teeth within them. One without the other rarely gives a stable result.

 

How long does the whole treatment take? Typically one to two years from the start of the pre-surgical orthodontics to the removal of the braces afterwards.

 

Will it change how I look? Yes, that is inherent to moving the jaws. How much depends on the movement required, and digital planning is used to show the likely result beforehand.

 

Is it painful? The surgery is carried out under general anaesthesia. Afterwards most patients describe the swelling, numbness and dietary restriction as more difficult than pain, which is generally well controlled with medication.

 

Can it be done at any age? It is usually carried out once facial growth is complete, which is typically in the late teens, though it is performed at any adult age.

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