Breast implants are a type of medical prosthesis used for enlargement and reconstruction of the breasts. They come in two basic types - saline filled and silicon gel filled. They are used by plastic surgeons for breast reconstruction following a mastectomy, to correct congenital defects, for breast enlargement and for gender change surgery. The first use of such implants dates back to the late 19th century, where they were often used for small repairs after minor surgery, such as removal of a tumor. Modern implants date to the 1960s and the first silicon filled gel sacks.