Commercially known as AlloDerm and known to physicians as acellular human cadaveric dermis, AlloDerm comes from tissue donors Just after death, technicians remove a layer of skin, remove the epidermis, and treat the remaining dermis with antibiotics and other substances to remove the donor's cells and DNA that would cause rejection. The graft that emerges is often used to cover chin implants. Other implant materials include Supramid, a braided nonabsorbable synthetic suture material in polymer shell and Mersiline, a mesh-like material that provides a scaffold on the bone. Types of procedures Surgical chin augmentation - The most common type of surgical chin augmentation uses a chin implant. There are many types of chin implants, and many are described in the previous section. Chin augmentation with a chin implant is usually a cosmetic procedure. An incision is made either under the chin or inside the lower lip, a pocket is made and the implant placed into the pocket. Some chin implants are fixed to the mandible, while others are held in place by the pocket itself. Another surgical chin augmentation uses the lower prominence of the mandible as the "implant." Known as a sliding genioplasty, the procedure involves cutting a horseshoe-shaped piece of bone from the lower border of the mandible known as an osteotomy. For chin augmentation, the piece of bone is advanced forward to increase to projection of the chin. The piece can also be recessed backward for a chin reduction. The new position is held in place with a titanium step plate using titanium screws. The bone segment can also be fixated with 26 or 27 gauge wires and IMF (wiring the jaw shut) for 3-4weeks. This type of surgery is usually performed by an oral and maxillofacial surgeon or a plastic surgeon. More involved Orthognathic Surgery may be required in cases where the chin is small and a significant overbite co-exist. While the procedures above may improve the cosmetic appearance of the chin, they will not improve dental occlusion. Mandibular advancement surgery can be used to correct the alignment of the teeth and improve the projection of the chin. Non-surgical chin augmentation - Another method of chin augmentation uses an injectable filler. Most fillers are temporary, with results lasting months to years. Common temporary fillers include hyaluronic acid and calcium hydroxyapatite preparations. Permanent fillers, like "free" silicone, have fallen out of favor due to the risk of