Jump to Post-mastectomy procedures - Breast augmentation and augmentation mammoplasty are plastic surgery terms for the breast-implant and the. Jan 10, - Breast augmentation is done by placing implants behind breast tissue or under the chest muscle. An implant is a sac filled with either sterile salt water (saline) or a material called silicone. The surgery is done at an outpatient surgery clinic or in a hospital. Most women receive general anesthesia for this surgery.