What is orthognathic surgery?

Orthognathic surgery is surgery performed on the jaw and skull that corrects functional and aesthetic problems due to underlying skeletal and/or dental deformities. Some of the issues corrected through orthognathic surgery include:

•  orthodontic problems that cannot be corrected through braces alone, such as certain cases of open bite, cross bite, overbite and underbite;
•  protruding jaw, receding chin, inability to close lips over teeth easily, and asymmetric jaw;
• excessive wear of teeth, and periodontal trauma;
• difficulty chewing or biting food;
• speech problems;
• sleep apnea; and
• jaw joint (TMJ) pain.

Surgery is performed by a qualified oral and maxillofacial surgeon and often requires months to years of orthodontics before the surgery to ensure teeth are in the proper position. The surgery is performed under general anaesthetic and may take several hours to complete, depending on the procedure(s) being done.

There are three general types of orthognathic surgical procedures:

Bilateral Saggital Split Osteotomy (BSSO)

Bilateral Saggital Split Osteotomy (BSSO) is a method of lower jaw (mandibular) surgery used to either lengthen or shorten the jaw bone. Mandibular advancement (lengthening the lower jaw) is used in cases of overbite (upper teeth outside lower teeth with a large gap between the two) and/or receding chin (weak chin), where the lower jaw has not grown long enough for the bite to fit together correctly.  Mandibular setback (shortening the lower jaw) is used in cases of underbite (lower teeth outside upper teeth) and protruding lower jaw, where the lower jaw has grown too long.

Lower jaw surgery is performed inside the mouth, behind the back teeth, so there are major external incisions; one tiny incision is made in each check, through which screws are inserted to secure the jaw bone in its new position. The jaw is either wired shut or held in place with firm elastics after the surgery for approximately two weeks, to ensure it heals properly.

LeFort Osteotomy (LeFort I, LeFort II, LeFort III)

LeFort I, II and II Osteotomies are methods of upper jaw (maxillary) surgery used to reposition the upper jaw in cases of open bite (where only the very back teeth meet when the jaw is shut, causing excessive wear on these teeth), overbite (upper teeth outside lower teeth with a large gap between the two), underbite (lower teeth outside upper teeth), long face, short face, gummy smile (entire upper gum area is visible when smiling) and other cases where the upper jaw area has grown too long, or not grown long enough for the bite to fit together correctly.

This surgery sometimes may change the shape of the patient’s nose and also may affect the sinuses.

Upper jaw surgery is performed inside the mouth, so there are no external incisions. The jaw is either wired shut or held in place with firm elastics after the surgery, for up to eight weeks, to ensure it heals properly.

Genioplasty

Genioplasty is a surgery in which the chin is moved forward (to correct a receding or weak chin), back (to correct a protruding chin), up (to shorten it) or down (to lengthen it), to improve the appearance of the chin and the balance of the face. A Sliding Genioplasty, where a piece of the chin bone is slid forward or backward and secured in place with screws, is often performed in conjunction with lower jaw surgery. In cases of a receding chin, a chin implant may be inserted during the surgery to create a more prominent chin. Genioplasty is performed inside the mouth, so there are no external incisions.