Buttock augmentation, or gluteal augmentation, is used to improve the contour, size and/or shape of the buttocks. This is done through the use of buttock implants, fat grafting or sometimes a combination of the two. Buttock implants are silicone-filled devices that are surgically placed deep within the tissues of the buttock. Buttock augmentation through the use of fat grafting involves the transfer of fat from one area of the body into the tissues of the buttocks. This technique is sometimes referred to as a Brazilian Butt Lift.