Fifty years ago, a team of doctors found that silicon could be used to enhance the size, shape and feel of breasts — a major advancement over the other substances being used as breast implant fillers, including ox cartilage, ivory and glass balls.

Plastic surgeon Denis Boucq holds a defective silicone gel breast implant. (ERIC GAILLARD/REUTERS)

Now, half a century after those first experimental globes were born, silicone breast enlargement is the most popular cosmetic surgery procedure in the United States. In 2010, 296,203 breast augmentation procedures were performed, according to the Food and Drug Administration. From 5 million to 10 million women worldwide have had the surgery. But how many of them know the storied history of the prosthesis that lies within their breast? A short history below:

The 19th century:

At top, a silastic rubber gel mammary prothesis. At bottom, an X-ray of the prosthesis after implantation. (Dow Corning/Creative Commons)

The 20th century:

Cronin created a prototype of the silicon implant. The first living thing to try it out: a dog named Esmeralda.

Women had been clamoring for breast implants for decades. In her book “Inventing Beauty,” Teresa Riordan writes that in the early postwar years, surgeons were not interested in the medical disability of “hypomastia” — the condition of having small breasts. But women who were inspired by fashion magazines and buxom actress Marilyn Monroe pushed for a surgical solution.

The 21st century:

While thousands of breast implants have gone off without a hitch, recent years have revealed a darker side to the procedure. Several studies have investigated the correlation between psychological distress and implants. (The finding: There’s a strong link.) A 2008 longitudinal study found that women who have tried to get breast implants are almost three times more likely to commit suicide than women who have not tried.

Patients who received defective silicone gel breast implants manufactured by French company Poly Implant Prothese (PIP) had their implants removed out of safety concerns. (Lionel Cironneau/AP)

Concerns about silicon have recently been raised in the States.

In June the FDA reported that silicon implants still appeared to be relatively safe for most women, so long as they realize they come with complications. An outside panel of physicians affirmed that conclusion.

But women’s health safety advocates questioned the FDA’s findings in a letter to the agency last week. The National Research Center for Women and Families said the agency left out data that showed that women faced emotional, mental and physical issues after implantation.  The group also said the FDA wrongly noted that implant complications decline over time, when in fact they fail over time.