The basis of the FDA's decision on breast implants.

On April 16, 1992, the Food and Drug Administration announced that breast implants filled with silicone gel would be available only through controlled clinical studies and that women who need such implants for breast reconstruction would be assured of access to these studies. This decision was especially difficult because even after more than 30 years of use involving more than 1 million women, adequate data to demonstrate the safety and effectiveness of these devices do not exist. They had been allowed to remain on the market after the enactment of the 1976 Medical Device Amendments ("grandfathered") with the understanding that . . .