Indications for Orthognatic Surgery

Excess mandibular bone causes protrusion of the lower jaw beyond the normal alignment with the upper jaw. This can prevent effective biting and chewing of food and hastens periodontal disease. Temporomandibular joint function and speech may be impaired. Excessive chin hyperplasia or malposition may require a reduction or sliding genioplasty. Retrognathia or micrognathism is a deficiency of the mandibular bone. This does not allow the upper and lower teeth to come together when chewing food and may affect speech. Sleep apnea may also be produced by a retruded or deficient lower jaw. A deficiency of bone supporting the chin may require surgery (genioplasty) to build up the tissue and provide a normal framework for the chin. In this condition, also called hypoplasia, the growth of the maxilla does not match that of the lower jaw. There is a collapse of the normal mid-face supporting structures. In addition to causing difficulties with eating and speech, this deficiency may be associated with anomalies of the supporting structures of the nose and cheeks.