Chin augmentation using surgical implants can alter the underlying structure of the face, providing better balance to the facial features. The specific medical terms mentoplasty and genioplasty are used to refer to the reduction and addition of material to a patient's chin. This can take the form of chin height reduction or chin rounding by osteotomy, or chin augmentation using implants.
This operation is often, but not always, performed at the time of rhinoplasty to help balance the facial proportions. Chin augmentation may be achieved by manipulation of the jaw bone (mandible) and augmentation utilizing this technique usually provides a more dramatic correction than with the use of prosthetic implants.
Chin implants are to build a better profile. Patients’ own bone is donated from ribs and from part of the pelvis (the ilium.) Unfortunately, use of donated bone implants in chin augmentation, even the patient’s own, appears to be associated with a higher rate of infection, even after the implant has been in place for decades.
Chin augmentation is still popular because it’s a relatively easy operation for the patient while producing noticeable changes in the silhouette of the face. This type of surgery is usually performed by an oral and maxillofacial surgeon, otolaryngologist, or plastic surgeon.
Potential risks and side effects 
The usual complications are relatively minor and include swelling, hematoma (blood pooling) and numbness of the lower lip, which usually does not last long. Other, less common risks include infection, bony changes and displacement of the implant.
Chewing should be kept at a minimum immediately after this procedure, so it may be beneficial for you to find a liquid or soft food diet you enjoy for several days. You may also feel a tight sensation around the chin. However, this typically subsides within a week. 
Chemical compositions 
Gore-Tex used in plastic surgery and other operations is known by an abbreviation of its chemical name, ePTFE (expanded polytetrafluoroethylene) or Gore S.A.M. (subcutaneous augmentation material.)
ePTFE is used in medicine because it is biocompatible and does not cause problems inside the human body. Because ePTFE is flexible and soft but very strong, it is inserted during operations in trimmed sheets and carved blocks and held to the bone by titanium screws. But because the material is porous, the force that really holds the implant in place is soft tissue and bone growing through and into the implant.
Another chin augmentation implant material is commercially known as AlloDerm and known to physicians as acellular human cadavertic derms. AlloDerm comes from tissue donors; just after death, technicians remove a thin layer of skin and use antibiotics and other substances to remove the cells and donor DNA that may cause rejection. The graft that emerges is often used to cover chin implants. Other typical types of chin implants include silicone implants in varying degrees of softness; silicone elastomers (any of various polymers having the elastic properties of natural rubber) and porous polyethylene implants. Other common implant materials include Supramid, a braided nonabsorbale synthetic suture material in polymer shell and Mersiline, a mesh-like material that provides a scaffold on the bone.
Types of procedures 
A particular process, known as a sliding genioplasty, involves mobilizing a horseshoe-shaped piece of the bottom part of the chin bone by osteotomy and sliding it either backwards or forwards, finally fixing it in place with a titanium step plate using titanium screws. The bone segments can also be fixed by using 26 or 27 gauge wires and IMF given for 3-4weeks. This type of surgery is usually performed by an oral and maxillofacial surgeon or a plastic surgeon.
See also 
- Aufricht, G: combined plastic surgery of the nose and chin; resume of twenty seven years’ experiences. Am J Surg 1958 Feb;95(2): 231-6
- Costantino PD. FriedmanCD: Soft-tissue augmentation and replacement in the head and neck. General considerations, Ontolaryngol Clin North Am 1994 Feb;27(1): 1-12
- Gore Medical Products Maas CS, Merwin GE, Wilson J, et al.: Comparison of biomaterials for facial augmentation. Arch Otolaryngol Head Neck Surg 1990 May; 116(5): 551-6.
- Guyuron B, Raszewski RL: A critical comparison of osteoplasic and alloplastic augmentation genioplasty. Aesthhetic Plast Surg 1990 Summer, 14(3): 199-206
5. White JB, Dufresne CR. Management and avoidance of complications in chin augmentation. Aesthet Surg J. 2011 Aug 1;31(6):634-42.