Chin Surgery: Genioplasty

Why is Genioplasty done?

The chin can be moved forwards to correct a retrusive chin. It has the advantage over a chin implant in that it is not a foreign body as it is the patient’s own bone. A silicon chin implant can also move or rotate over time, and has been shown to sometimes resorb (erode) the underlying chin bone due to long term muscle tension. It is also preferable to have your own bone (genioplasty) rather than a silicon implant placed in a younger person. It can be moved backwards to reduce a protrusive chin. It can be moved sideways to correct asymmetry. It can also be rotated downwards to lengthen a chin, and sometimes reduce the deep fold between the lip and chin. Altering the chin position is often to improve facial aesthetics. A functional outcome is sometimes possible in selected cases due to being able to improve the position of the muscle that runs from the chin to the lower lip (mentalis muscle) and can improve the ability of the lips to better approximate each other.

 

How is genioplasty done?

Genioplasty is not a very invasive procedure and can be done as a day only procedure or one overnight stay. An incision is done in the gums below the lower front teeth under the lower lip. There are no skin incisions. Using a small hand saw, the chin bone is sectioned and mobilized. The chin can be slid forwards, backwards, sideways, upwards or downwards.  No bone grafting is needed as it is a “sliding” action and there is still good bone contact. Occasionally, if the chin is lengthened and there is a small gap, artificial bone graft (bone cement) may be used. The amount of movement will depend on the surgical planning and aesthetics desired. The chin is held in place by titianium plates and screws. There are specialised chin plates which are pre-bent to different sizes (3mm to 8mm) to allow precise movement as per planned desired change.

 

How much time off do I need?

There is often swelling and bruising around the lower jaw and chin and may extend down to the neck. This will take 2 to 3 weeks to resolve. The pain is not severe and usually present for the first week and oral pain medication is often all that is required for the first 5 to 7 days.  Most patients are back at work or school by 2 weeks but it will take at least 6 weeks for the oedema to completely resolve.

 

What are the risks of genioplasty?

The main risk is the possibility of nerve injury and numbness of the lower lip and chin. There is a nerve that exits the jaw just above where the cuts need to be made. It is called the mental nerve and it exits from a small opening in the bone called the mental foramen. This nerve is always carefully visualised and protected during surgery and is rarely damaged. The risk of numbness is often temporary and rarely (although possible) permanent.  The other risks are: infection (very rare), exposure or irritation of the plates/screws (can be removed) and that the aesthetic result is not as expected (care is taken with computer imaging and discussion to ensure outcome is consistent with planning).