Do solid silicone pec implants need to be replaced every 10-20 years like breast implants?

If your implant is truly displaced, which can be confirmed only on the basis of in person exam, the only option is to close the space in the lower pole of implant capsule and lift implant in more symmetric position. This will require scar in the pectoral crease to perform lower pole capsule...

Based on these photos, you are good candidate for correction with transfer of latissimus dorsi muscle from the back to anterior chest. This will improve appearance of the chest, including nipple areola position and size. There is no noticeable deformity on the back. Muscle stays innervated and...

Although I understand your line of thinking, this would not be a good idea as the breast implant will create more of a breast shape projection and not a masculine pectoral muscle contour. Although the average pectoral implant is not quite as soft as muscle, hardness is usually not a complaint...

Indeed you seem to exhibit the classic and most basic sign of Poland Syndrome, displaying absence of the sternal head of the pectoralis major muscle. Pectoral implants are typically a good option for someone like yourself. The implants do move somewhat with movement of the arm.  ...