Disclosed is a mammary prosthetic implant with an expandable mammary prosthesis that expands to an enlarged state after implantation. A prosthetic device supports, and conforms to the shape of, the mammary prosthesis before, during, and after the mammary prosthesis is expanding within the implantation site. The prosthetic device has an absorbable main body formed of other than biological tissue, and is penetrable for the in-growth of dermal or subcutaneous tissue. The main body has an anterior end portion, an opposite posterior end portion, and a size relative to the mammary prosthesis upon implantation so that the anterior end portion engages an incised portion of a pectoralis major extending anteriorly of the mammary prosthesis while the opposite posterior end portion engages tissue inferiorly spaced from the incised portion of the pectoralis major and near the inframammary fold. Methods of preparing and using a prosthetic device as described herein also are disclosed.
