Reconstructive surgery is executed to treat those parts of the body which are functionally or aesthetically affected by congenital defects, trauma, developmental abnormalities, tumors, infection, or disease. It is generally performed to improve function and ability. This varies from cosmetic surgery which is performed without a medical reason. Surgeons who perform reconstructive surgery have special expertise in plastic surgery for a particular area of the body, such as the face, breast, trunk, upper and lowerextremities, or hands. Reconstructive surgery is most commonly used after some types of surgery, specifically to remove the cancer. For example, after a mastectomy mostly patients choose to have reconstructive surgery. Another example is when a plastic surgeon or otolaryngologist replaces nerves or tissue during treatment for skin cancer. This type of surgery also involves transplantation in some cases.