Thank you for your question. I would first like you to know that the decision to go behind the muscle or over the muscle has to do with the amount of soft tissue coverage – “padding” you have under the skin. Choosing a pocket that is tight with sufficient soft tissue coverage not only prevents implant visibility, palpability, and risks of excessive stretching on the breast, but also excessive implant movement into the outer or inner sides of the breasts. A hand-in-glove fit for the implant allows for a natural and long-lasting result. Your surgeon will do a pinch test in the upper pole of the breast to see how much “padding” you have. If you have less than 2 cm, then you do not have much padding and it would be best to go under the muscle. Generally speaking, if your ribs are visible under the muscle, then you do not have much “padding.” If however, you have more than 2 cm of tissue, then you have the option to go over the muscle or under the muscle. Which pocket do you prefer? OVER THE MUSCLE If you are hoping to fully preserve the functionality of the pectoralis major muscle due to athletics or body building, or if you have a shapeless, constricted, tuberous, sagging breasts without cleavage, then over the muscle may be a better option. Over the muscle implant placement causes less trauma to the chest muscles, and the implants will not be subjected to any pressure or injury due to muscle movement.The implant can directly apply pressure on breast tissue to shape the breasts.However, over the muscle implant placement may have higher risks of breast tissue wasting, interference with mammography, and capsular contracture compared to under the muscle placement.Higher risk of implant visibility and palpability is possible if you are thin, and this can be fixed used fat grafting where areas with less tissue coverage are filled with your own fat to provide better contour and coverage. UNDER THE MUSCLE Under the muscle (partially submuscular) is a preferred option for many surgeons because the muscle helps to maintain a slope for the upper pole while allowing for a curvature in the lower pole, while over the muscle will mostly make your breasts appear round and augmented. In thin patients, additional coverage by the muscle reduces the risk of implant visibility in the upper and inner sides of the breasts. It also reduces risk of synmastia, and provides less interference with mammography and breast imaging. It also brings lower rates of capsular contracture.However, under the muscle implant placement may allow the chest muscles to put pressure on the implant distorting the breast shape and position in the long-term. You may experience more pain following surgery due to the dissection of some muscle attachments and you may lose strength while flexing your chest muscle and is not suitable for athletes and body builders. So which pocket allows a more natural feel? It truly depends on the amount of soft-tissue coverage, the size of the implant, and the fill of the implant. If there is sufficient soft-tissue coverage and the implant is adequately sized, then there will be no implant palpability and visibility. Additionally, silicone breast implants will provide a more natural feel compared to saline implants. It is important that you communicate your goals very clearly, but understand that you need to have realistic expectations. Hope this helps, and best of luck!