Tissue Expanders are often inserted as a first stage of breast reconstruction during the mastectomy. The tissue expanders can be placed above the muscle or below the muscle and depending upon the type of reconstruction that is going to be undertaken. When the tissue expander is placed beneath the pectoralis major muscle it often assumed a higher position that expected and then will descend to a lower position based on gravity, swelling, and the forces of the pectoralis major muscle. Often when patients undergo radiation therapy, the radiated side will displace the tissue expander superiorly. The second stage of the breast reconstruction, which is the insertion of the mammary prosthesis, does not occur until approximately one year after the completion of radiation therapy. At this time the tissue expanders are removed, and either silicone or saline mammary prosthesis are placed in a pocket with a more improved position.