Breast augmentation and augmentation mammoplasty (colloquially known as a "boob job") are plastic surgery terms for the breast-implant and the fat-graft mammoplasty approaches used to increase the size, change the shape, and alter the texture of the breasts of a woman. As a primary reconstruction, augmentation mammoplasty is applied to effect a post–mastectomy breast reconstruction, the repair of the chest wound consequent to the removal of a cancerous breast; to correct congenital defects of the breast(s); and to correct congenital defects of the chest wall. As an elective, cosmetic surgery, primary augmentation changes the aesthetics – of size, shape, and texture – of healthy breasts.
The surgical implantation approach effects the global augmentation of the breast hemisphere using a breast implant, either an implant filled with saline-solution, or an implant filled with silicone-gel; moreover, the surgical augmentation approach can include the application of transplanted autologous skin flaps harvested from the woman's body. The fat-graft transfer approach augments the size and corrects contour defects of the breast hemisphere with grafts of autologous adipocyte fat tissue, drawn from the woman's body.
In a breast-reconstruction procedure, within a multi-stage reconstruction-mammoplasty, a tissue expander (a temporary breast-implant device) is emplaced and used to prepare (shape and enlarge) the recipient site (implant-pocket) to receive and accommodate the breast implant prosthesis. In a non-implant breast-augmentation procedure, some fat-graft injection approaches feature tissue-engineering, which is the pre-operative, external expansion of the tissues of the recipient site to receive the grafts of adipocyte tissue drawn from the woman's body. Non-surgical approaches to breast augmentation can consist either of an externally applied vacuum-device that will expand the tissues of the recipient site. Moreover, in most instances of fat-graft breast augmentation the increase is of medium volume – usually one brassière cup-size or less – which usually is the physiologic limit allowed by the metabolism of the woman's body.