WASHINGTON (CNN) -- The FDA is allowing silicone breast implants to be sold again, 14 years after they were removed from the market by the same agency over questions of safety.

The approved silicone implants are made by two companies, Inamed Aesthetics, now a part of Allergan, and Mentor.

The FDA says these implants are approved "for breast reconstruction in women of all ages and breast augmentation in women ages 22 and older."

Daniel Shultz, director of the FDA's Center for Devices and Radiological Health, told reporters that younger women's breasts continue to develop through their teens and early 20s, and the agency wanted to make sure breast development was completed before women had devices implanted.

In 1992, then-FDA Commissioner Dr. David Kessler took silicone breast implants off the market, citing concerns over their safety, including how often they ruptured in a woman's body and whether leaking silicone could lead to diseases as some women claimed.

After the ban, the implants were available only to women in clinical trials who needed them after surgery, especially after breast cancer. At that point, lawsuits over the products drove one of the manufacturers, Dow Corning, into bankruptcy.

Since then, most studies have failed to link the implants to serious or chronic diseases such as cancer and lupus, but questions remained over how often the implants rupture and what happens if the silicone enters the body.

In a meeting before an FDA advisory committee in April 2005, Inamed said its implants have a 14 percent likelihood of rupturing over a 10-year period. Mentor conducted a three-year study and said the rupture rate at that point was negligent.

To help answer questions on long-term safety, the FDA is requiring Inamed and Mentor each to study 40,000 women for 10 years to assess potential health problems.

The consumer advocacy group Public Citizen, which has long opposed silicone implants, criticized the decision and called it "a terrible reminder of the double standard for women versus men" and noted that the FDA has not approved silicone gel testicular implants because of inadequate testing.