Submuscular: the breast implant is emplaced beneath the pectoralis major muscle, without releasing the inferior origin of the muscle proper. Total muscular coverage of the implant can be achieved by releasing the lateral muscles of the chest wall—either the serratus muscle or the pectoralis minor muscle, or both—and suturing it, or them, to the pectoralis major muscle. In breast reconstruction surgery, the submuscular implantation approach effects maximal coverage of the breast implants. This technique is rarely used in cosmetic surgery due to high risk of animation deformities.
the second technological development was a polyurethane foam coating for the shell of the breast implant; the coating reduced the incidence of capsular contracture, by causing an inflammatory reaction that impeded the formation of a capsule of fibrous collagen tissue around the breast implant. Nevertheless, despite that prophylactic measure, the medical use of polyurethane-coated breast implants was briefly discontinued, because of the potential health-risk posed by 2,4-toluenediamine (TDA), a carcinogenic by-product of the chemical breakdown of the polyurethane foam coating of the breast implant.
The FDA has identified that breast implants may be associated with a rare form of cancer called anaplastic large-cell lymphoma, believed to be associated with chronic bacterial inflammation. Similar ALCL phenomena have been seen with other types of medical implants including vascular access ports, orthopedic hip implants, and jaw (TMJ) implants. As of February 1, 2017, the FDA has received a total of 359 medical device reports of breast-implant-associated ALCL (BIALCL), including 9 deaths. Most cases of breast implant-associated ALCL had implants in for many years prior to the condition, and are usually treated successfully by simple removal of the implant and the capsule surrounding the implant without the need for chemotherapy if no evidence of systemic disease exists. If women with implants present with delayed swelling or fluid collection, cytologic studies and test for a marker "CD30" are suggested. The American Society of Plastic Surgery (ASPS) states, "CD30 is the main diagnostic test that must be performed on the seroma fluid as routine pathology or H&E staining can frequently miss the diagnosis."  Diagnosis and treatment of breast implant associated ALCL now follows standardized guidelines established by the National Comprehensive Cancer Network.