Underbite Surgery

An underbite, also known as class III malocclusion, is a condition wherein the teeth of the lower jaw, when the mouth is closed in its natural position, are placed slightly ahead of the teeth in the upper jaw. Ideally, when the mouth is closed, none of the teeth should touch each other and the front lower teeth should be placed slightly behind the upper front teeth. Class III malocclusion is sometimes hereditary, though it may also be caused due to trauma, or because of abnormalities in the eruption pattern of teeth. If it is merely dental in nature, that is, if the jaw position is right but the lower teeth are slightly forwardly placed, the condition can be corrected with the help of orthodontic treatment. However, if the defect is skeletal in nature, then surgery might be needed.

An underbite correction surgery is advised, only after a final diagnosis. This is a major surgery that needs to be done under general anesthesia. Also, the preparation for the surgery starts well before a year from the date of the surgery, because orthodontic treatment has to be initiated to correct the initial problems of malocclusion, like, crowding teeth, and other such problems. Thus, the orthodontic braces are placed on the teeth so as to bring them into as much a desirable position, as possible. Once this procedure is over, the jaw surgery is done.

Surgical Procedures

Maxillary Correction
The maxilla is the upper jawbone. Sometimes, despite a normal and properly placed mandible, there is an underbite. Such a situation arises, only when there is a retruded maxilla. In such cases, the jaw surgery will involve maxillary advancement with the help of Le Fort I osteotomy. This surgery is performed under general anesthesia, wherein the maxilla is brought forward, so that a normal and proper occlusion (contact between the teeth) can be achieved.

Mandibular Correction
Most of the cases of underbite are due to a protruded mandible, that is, a forwardly placed lower jaw. In this type of surgery, what is opted for is known as a bilateral sagittal split osteotomy, or a BSSO. Before this procedure is undertaken, the wisdom teeth of the individual have to be extracted. First, under general anesthesia, the area of the mandible that is close to the angle is split in the region of the wisdom teeth. Then, the mandible is pushed backwards and fixed securely in its new position with the help of screws. It is ensured that the area where the bone is fixed, is rich in its blood supply, so as to hasten the recovery time. After the surgery, the upper and lower jaw are held in place with the help of elastic bands, so that there is no unintentional injury, which could further delay the healing time.

This surgery is quite similar to crossbite surgery and it costs anywhere between USD 20,000 – USD 30,000. There are a few risks associated with this procedure, like swelling, slight nerve damage, and possibly, a slightly altered appearance of the entire face. Children affected by this dental problem can be treated with the help of more conservative methods, especially, if the bone growth is not complete. The mandible can be conditioned in such a manner, that the malocclusion does not increase any further. However, if the bone growth is complete, then surgery is the only method for treatment.