Shares of

Inamed

(IMDC)

dropped Wednesday, a day after a federal advisory committee voted against its silicone-gel breast implant for use in cosmetic surgery.

The 5-4 vote of the panel of experts convened by the Food and Drug Administration said Inamed failed to prove the long-term safety of the implant. The FDA isn't bound by its advisory panels' recommendations, but it usually follows their suggestions.

The ruling, which came late Tuesday afternoon after markets had closed, doesn't portend well for

Mentor

(MNT)

, whose silicone-gel breast implant will be reviewed by the advisory panel today. A vote is expected in the late afternoon. Wall Street handicappers have said that Inamed's implant had a better chance of securing FDA advisory committee support.

On Wednesday, Inamed's stock dropped $2.96, or 4.5%, to $63.45 in early trading. Mentor's stock was off 74 cents, or 2.1%, to $33.82.

This was the second defeat for Inamed. In October 2003, an advisory committee voted 9-6 to support its silicone-gel implant application. A few months later, the FDA rejected the application, saying the company had failed to provide proof of the device's long-term safety.

Since 1992, the FDA has severely restricted silicone-gel implants to a few uses, such as breast reconstruction after a mastectomy and replacement of a ruptured silicone implant. Although silicone implants entered the U.S. market in 1962, the FDA didn't receive legal authority to regulate them until 1976.

Over the years, the FDA

strengthened its regulations to a point in 1992 in which manufacturers had to show comprehensive, long-term safety data to support applications for new implants or to keep older ones on the market. As a result, silicone implants, which are sold in many countries, aren't available in the U.S. except in rare circumstances.

Saline-filled breast implants are sold in the U.S. for cosmetic surgery purposes. The implant industry and plastic surgeons have sought FDA approval of silicone implants, saying the new products are superior to past devices. They add that women should be given the opportunity to make an informed decision on a product that many say provides a more natural look and feel than salt-water-filled implants.

The silicone-gel implant applications for Inamed and Mentor were criticized last week by FDA staff members, who issued reports saying the companies'

research was inadequate to prove long-term safety and to assess the rate of implant ruptures over time.