Placement of a breast implant under the muscle or on top of the muscle is a topic frequently asked about and always discussed during a breast augmentation consultation. The muscle that is being referred to is the pectoralis muscle. This is a muscle on the chest wall that is on top of the ribs. A breast implant can be placed either on top of this muscle or underneath this muscle. Placing the breast implant underneath this muscle has several advantages. When the implant is under the muscle, there is more soft tissue (the pectoralis muscle) over the implant. This gives the breast a more natural look and feel. The second and very important advantage is that a breast implant under the muscle has a much lower risk of developing a capsular contracture when compared with a breast implant placed on top of the muscle. Finally, when a breast implant is under the muscle, it is easier to perform and read mammograms then if the implant is on top of the muscle. While placing a breast implant on top of the muscle is probably easier to perform, it has the disadvantages of a less natural look and feel, much higher capsular contracture risk, and causes more difficulty with mammograms. For these reasons it is preferred to place the breast implant under the muscle in most cases. Situations where placement of the breast implant above the muscle is considered include cases when a woman already has a breast implant above the muscle, and desires exchange for change of size or change of filler (saline to silicone gel). Even in these cases the implant location can be changed from on top of the muscle to underneath the muscle if desired. These issues are best sorted out with a thorough in person consultation with a board certified plastic surgeon.