I like saline implants above the muscle when the patient... ...already has a fair amount of breast tissue. Saline implants tend to ripple more than silicone. Hence, those implants need some sort of coverage to camouflage that rippling. That coverage can come from the muscle or from breast tissue. If a woman's breasts are already big, but she would like them even bigger, placing implants on top of the muscle is usually OK. ...wants the most natural results when she exercises (nearly) naked(!) The breasts are naturally on top of the muscles. Therefore, if the muscles move, the overlying breasts shouldn't move that much. However, if the implants are beneath the muscles, the breasts might move unnaturally when the muscles contract. Since most women don't exercise naked, this is a minor issue for most patients. Nevertheless, some women do compete in sports in small bikinis, and they are aware of breast distortions with shoulder/chest muscle contractions (such as beach volleyball players, surfers, body builders...see below) ...is a body builder. Body builders have very well developed muscles. Contraction of those big muscles would significantly distort the positions of sub-muscular implants. These women do pose nearly naked (in small bikinis) while flexing their muscles. Even though these women do not have a lot of body fat, implants on top of the muscle are generally better. In competitions, the rippling of the implants looks less bad than implant distortion. ...has droopy breasts and prefers to avoid formal lift-up procedures Implants themselves provide breast rejuvenation. The muscles tend to mute the rejuvenative/lift-up effects of breast augmentations. Even though many women need mastopexies (lift-up surgeries) at the same time as their augmentations, some patients prefer to avoid the additional scars of mastopexies and accept the limitations of implants on top of the muscles. ...is looking for a quicker recovery Most breast implants surgeries do not require a long recovery. However, positioning of the implants below the muscle is more uncomfortable. Staying on top of the muscle is much less painful. Generally, I use silicone implants when patients choose to have their augmentations on top of the muscle. Or, better yet, I place implants beneath the muscle in 90% of circumstances... to minimize rippling to reduce excess scar tissue around the implants (known as capsular contracture)