What are risks?
Twenty odd years ago, a very good friend of mine was taking his oral examination in the Royal College of Surgeons for his Fellowship. He was being grilled by the examiners about the risks involved in a certain surgical procedure on a certain part of the brain (microvascular decompression of the trigeminal nerve if you have to know). He's a bright chap but perhaps the pressure of the examination gave him a brain freeze and he was stumped. He had already listed a whole bunch of risks but one examiner was pressing for one more. Frustrated, he thought the worst thing that can happen was that the patient would die right? So, he blurted out "death". The examiner shouted, "Correct! Hearing loss! That's the answer I've been waiting for!" My friend was shocked but happy. He passed.
All surgeries have risks. But risks are relative. The decision to have surgery is made when the benefits of the surgery outweigh the risks. The same surgery carries a different set of risks for different patients based on their medical history, their current medical status, etc. Cosmetic jaw surgery is an elective procedure without which the patient will not die. As such, the risk benefit ratio needs to be kept low to justify having the surgery. As a general rule, cosmetic procedures should not be done in medically compromised patients unless there are good justifications for them.
General anesthesia is a risk factor in any surgery. However, if the patient is not medically compromised and general anesthesia in the hands of a good anesthesiologist working in a well equipped hospital is generally safe. Having the anesthesiologist has the added advantage of having an independent opinion on the patient's general fitness to undergo surgery.
The risks that relate to the surgery proper are:
1. Nerve injury
Sensation in the face is provided by the Trigeminal Nerve. This nerve has branches that run through the facial bones and exit through the bone into the skin, providing sensation to the face. Of particular importance in corrective jaw surgery are two pairs of nerves; one in the upper jaw, and one in the lower jaw. In the upper jaw, the nerves emerge through a hole just below the eye and they provide sensation to the mid face. Orthognathic surgery involves shifting the position of the upper jaw and it carries a risk of stretching these nerves which may result in a numbing sensation of the midface. In the lower jaw, the nerves run internally within the jaw bone and exit around the region of the premolars to enter the lips, providing sensation to the lower lip and chin. Lower jaw surgery carries a risk of injuring these nerves which will manifest as numbness of the chin and lower lip areas. In majority of cases, this numbness will resolve spontaneously but there are some patients who do experience the numbness on a permanent basis.
2. Excessive blood loss
Cosmetic jaw surgery can be rather bloody, especially upper jaw surgery, because the jaw bones are well supplied by many blood vessels. This is a major advantage for healing but it also gives rise to more bleeding during surgery. We minimise the blood loss by using hypotensive anesthesia, whereby the blood pressure is lowered during the surgery. However, it is still very common for the patient to loose up to 1 litre of blood for corrective jaw surgery. As such, blood transfusion is usually needed. For jaw surgery in Singapore, I advocate the use of autologous blood ie the patient goes to the blood bank are scheduled intervals to "bank" his own blood for use during the surgery, to minimize the risks associated with the use of other people's blood,
Infection can affect all surgical wounds and the jaws are no exception. However, due to the good blood supply of the face and jaw bones, infection following corrective jaw surgery is not very common. However, infection can take place some months or even years after surgery. This is because of the internal fixation plates that are used to secure the jaw segments together. These plates may become exposed through the gum and when they do, infection can take place. The treatment then is to remove the plates and screws.
4. Non-healing wound
Infection can result in non-healing of the surgical wound if it happens soon after the surgery. The fixation plates serve the function of immobilizing the segments so that healing can take place. If infection sets in before bone healing is complete, the wound may not be able to heal. If this happens, the infection will need to be treated either surgically or medically, followed by cleansing of the wound and re-fixation to allow proper healing
5. Damage to teeth
Some techniques in corrective jaw surgery involve cutting through the jaw bones close to the roots of teeth. In some situations, the roots of nearby teeth may be cut by the saw that is used for cutting bone. If that happens, the injured tooth may either be saved by doing a root canal treatment or if that is not possible, it may have to be extracted.
6. Aesthetic objectives not achieved
Most patients seeking corrective jaw surgery also have aesthetic objectives in mind. Sometimes, that may be the only objective. However, aesthetics is an abstract concept and what the surgeon regards as aesthetic may not seen as so by the patient. This can happen even with the use of modern surgery simulation software that can predict the surgical results as there is a certain degree of inaccuracy inherent in these systems. To minimize this risk, I advise patients not to make hasty decision. Usually a bit more time spent in consultation can help the surgeon to understand what kind of aesthetics the patient is looking for. It is also beneficial to the patient as he can the understand better the limitations of surgery .
7. Positional change
Corrective jaw surgery is about changing the position of the jaw bones. However, these bones are attached to muscles and skin. When we move the segment of bone from its original position while it is still attached to the soft tissue, the soft tissue will have a tendency to pull it back to its pre-surgical position. This can also happend if the patient is still growing after the surgery. The late growth can result in under-correction and pose a problem with the bite as well as the facial aesthetics.
8. Rare complications
A double jaw surgery is not a small surgery. In fact, in the Table of Surgical Procedures published by the Ministry of Health, it is graded as Table 7C, which is the highest surgical table. As such, it is possible that one can die from such surgery. Fortunately, this is an extremely rare complication. There are other rare complications such as blindness that may happen with some surgery such as Le Fort III osteotomy whereby the bone cuts are close to or involve the eye sockets. Again, this is an extremely rare complication. In fact few patients need procedures like a Le Fort III osteotomy.
Think it through...
Cosmetic jaw surgery is an elective procedure. That means that you have the luxury of time to think it through, weigh your options, and proceed only if you are absolutely clear that you want it. If you are happy with the way you look and the bite does not bother you, there is no need for cosmetic jaw surgery. However, aesthetics do play a major role in society today, whether we like it or not. There are enough studies out there that proved that good looking people have certain advantages. Even babies instinctively gravitate towards people who are more attractive looking. Do your research, think it through and if in doubt do not hesitate to get a second opinion.