Jaw reconstruction

Abstract

The major deformities of the mandible can be classified under three distinct groups: 1. 1. Those in which there is loss of bone with the continuity of the mandible definitely disturbed. 2. 2. Those in which there is maldevelopment and retrusion of the mandible. 3. 3. Those in which there is overdevelopment of the mandible, such as occurs in prognathism and “open-bite.” The main causes of loss of bone in the mandible are osteomyelitis, trauma (especially gun-shot wounds), and surgical intervention for the removal of growths. The general outline of treatment consists of transplantation of bone and the construction of prosthetic appliances. Transplantation of bone is the desirable procedure whenever it is considered practical. The writer prefers osteoperiosteal grafts, even in large defects. Prosthetic restorations have a definite place in the restorative treatment of the mandible. Their main function is to hold the remaining segment of the mandible in normal position, in order that the existing teeth may perform their masticating duties. Symmetrical bilateral retrusion of the mandible may be due to birth injury, trauma, infection involving both sides of the mandible, or bilateral ankylosis at an early age. The treatment consists of advancing the anterior part of the lower jaw by making a diagonal or l-shaped incision on each side of the mandible. Asymmetrical retrusion of the mandible shows the chin markedly retracted and one side of the mandible shorter than the other. The correction of such deformities involves lengthening the short side of the mandible, supplemented by transplantation of bone or cartilage to obtain prominence of the chin. Prognathism of the mandible and “openbite” form a definite type of deformity. Prognathism is treated by two methods. First, by the removal of a measured section of bone from each side of the body of the mandible and pushing it back into its new position; or second, by cutting through the ramus and holding the entire lower jaw in the new position. The relative merits of these two methods are discussed in detail. Previous to operation, it is necessary to make preparations in the form of measurements and dental splints, or postoperative treatment in the form of orthodontic work or other dental treatment may be required.