Objectives of this study are to gather safety data regarding short term, post-implant events and complications needed to support Premarket Approval (PMA) submissions for Mentor Silicone Gel-Filled Mammary Prostheses and to maintain a comprehensive record of the patient's ongoing medical history. The FDA has placed the devices in a regulatory category as a Class III device, pursuant to the Medical Device Amendments to the Federal Food and Drug Act which went into effect in May 1976. For devices in this class, FDA requires certain clinical data regarding the risks associated with mammary prostheses. Due to several issues surrounding possible risks of silicone gel-filled breast implants, the FDA has mandated specific clinical study requirements to further assess possible risks and complications of silicone devices. Clinical data collected via this study will supplement data which will be collected in more extensive "Core" studies for breast reconstruction and augmentation procedures.