Augmentation mentoplasty using a custom-design wire cage

Abstract

Mentoplasty is often a complimentary procedure to rhinoplasty. At least 25% of all rhinoplasty patients may need a chin implant to balance facial features better. Augmentation mentoplasty using alloplastic implants such as silicone rubber or other materials provides a simple approach to the treatment of the hypoplastic chin. Although these types of implants are readily available in developed countries there are parts of the world where they are unavailable or quite expensive. The authors have developed a chin implant made of wire that is available throughout the world and is custom designed to the mentum of the patient after a cephalometric evaluation. This technique has been used in 125 patients along with rhinoplasty over the last 20 years at our institution. In an initial series of 8 patients the prosthesis became displaced and was removed in 2 patients. Since then a new radiographic technique has been developed to demonstrate the shape of the mentum before surgery and new bone formation after surgery. By using this special radiographic technique it was possible to detect four types of mentum before surgery and to construct a custom-design wire cage according to this shape. The prosthesis is constructed by an orthodontist according to the cephalometric measurements and shape of the mentum. By using the buccal approach a pocket is prepared subperiosteally and a wire cage is inserted. In the last 20 cases the wire cage was filled with diced cartilage wrapped with Surgicel. The results were esthetically satisfactory in most patients. After the shape of the wire prosthesis was modified to conform to the shape of the underlying bone better no displacement of the prosthesis has been experienced. In 3 patients it was necessary to remove the prosthesis when new tissue formation began to fill the prosthesis. These specimens were examined histologically and the regenerating tissue was found to be connective tissue with a thin layer of bone formation. Most patients could be followed up for only 3 to 12 years. In all patients the results have been consistent and the procedure has been safe.