Why can I see a fold/line on the bottom side of my breast after getting modest implants under the muscle? (Photo)

 Thank you for the question and pictures. It is difficult to advise you based on the one side photograph only. It is possible, that the breast implant has “drifted” below your inframammary fold. This will best be evaluated by your plastic surgeon.  If the appearance of the breast is of concern, internal suture “repair” of the inframammary fold area (capsulorraphy) may be indicated. Best wishes.

Thank you for your pictures. This shadow or line represents the implant. Increasing the size of implant would not necessarily improve this. 

What you are seeing is what we call a "double bubble".  The line you are seeing is the original inframammary fold.  The new inframammary fold is where the bottom of the pocket for the implant extends.  This can be repaired and will at least involve closing off the pocket with sutures and in some cases the repair may be reinforced with a material like Strattice.  If your original surgery was done by an experienced plastic surgeon certified by the American Board of Plastic surgery then he/she should be able to fix it for you.  This can occasionally happen to the best of us  but unfortunately most of the time I fix these, they are the result of poorly or untrained non board certified doctors who think that breast augmentation is easy to do and a great way to supplement their income.