If you get 350cc over the muscle, does your breast shape change much after?

Thank you for your question. Unfortunately the answer is not that simple. Many factors play a role in the overall shape of the breast after surgery such as quality of skin (thin over thick), skin laxity, position of the nipples in the first place in comparison to the infra mammary-fold, your existing amount of breast tissue etc.On average, the cosmetic outcome, in time, of a breast enlargement with implants behind the muscle is more stable, but again the decision on where to position the implants depends on the specific features of the patient and the size of the implants selectedHope it helps.Andrea MarandoPlastic and Cosmetic Surgeon, Manchester and London, UK

Whether you have over the breast or sub glandular implants, there will always be a change in the shape of your breasts. Usually, after a breast augmentation, you will start to see some changes and improvements in the shape of your breasts during the first few months. Over the course of your healing process, there will be a gradual improvement in your breasts. The question whether to have over or under the muscle implants would be answered by your surgeon, as he/she knows best about your condition and your chest measurements. Thus it would be best to discuss your concern with him/her. Usually, 6 months is enough for your body to fully recover from a surgical procedure. 

During the first several weeks after a subglandular augmentation.  There may be some rather rapid changes to the shape depending on the overlying tissue characteristics.  After a few weeks the result will stabilize but gradually over years there will likely be some further settling. 

With an over the muscle placement of breast implants there is no dynamic muscle movement that can flatten and or deform the shape of the implant. Therefore the compliance of the ability of the breast tissue and skin to stretch is really the only variable. After a few weeks, whatever shape the implant has changed the overall shape of the breast, will become evident. Over time, with gravity, the shape will change usually with loss of the fullness of the upper portion of the breast. Hope that's helpful.