While the most pronounced bone loss happened for men when they were 65 and older, the facial aging process starts earlier in women. Women's facial skeletons between 41 and 64 looked much different than their facial bones did between the ages of 20 and 40, according to the facial aging study.

Facelifts Won’t Fix Everything in an Aging Face

If you think of the facial bones as "scaffolding" for facial tissue and skin, the bone loss can contribute to that drooping, deflated look, explained study author Dr. Robert Shaw Jr., chief resident in the division of plastic surgery at the University of Rochester Medical Center in Rochester, N.Y.

Facial bone loss helps explain why getting a simple facelift, or skin tightening, won't ever make you look like your 20-year-old self, according to Dr. Shaw.

"The original thought was that skin goes through changes, such as a loss of elasticity and fat, so the primary approach to facial rejuvenation was skin tightening procedures," said Shaw. "But a lot of faces never looked like they did when they were younger. Patients bring in pictures and say they want to go back to that look, but they can never really go back to that look just by tightening their skin alone. If there are changes to those underlying structures it's going to change the appearance of how the skin looks."

The researchers did CT scans of the facial bones in 120 men and women aged 20 to 40, 41 to 64, and 65 and older. They then created three-dimensional reconstructions of the scans, which they used to take detailed measurements of the facial bone structure.

With age, the bone scans showed that the bones that make up the eye sockets recede, enlarging the sockets. A few less millimeters of bone for the soft tissues of the face to hold on to adds to the appearance of excess or droopy skin around the eyes, and definitely ages the face, resulting in pronounced facial aging..

Similar losses of bone volume happen in the bones of the middle face, including the brow bone, nose and upper jaw. The loss of bone volume can also reduce the angle of the lower jaw, which is why those with a strong jaw line in their youth may not be so well-defined in old age.

Throughout your life, bone is constantly being made and reabsorbed. Aging may cause the creation of new bone to work a little less well, perhaps causing more bone to be absorbed than is created, said Shaw.

It stands to reason. With aging, bone density can also decrease, leading to diseases such as osteoporosis, which tend to impact women more often than men.

"A nice, strong jaw line is something people see as being youthful, but as you get older the angle gets more blunted [because of bone volume loss]," says Shaw.

Fillers and Implants to the Rescue

Plastic surgeons can use cosmetic fillers, can move fat from one part of the body to the face or use facial implants to make up for the lost bone, according to Shaw.

"It's not ever possible to bring someone back to how they looked when they were 20 years old, but adding volume back to the face can improve results for some patients," says Shaw.

The facial aging study was published in the January issue of Plastic and Reconstructive Surgery.

SOURCES: Robert Shaw Jr., M.D., chief resident, division of plastic surgery, University of Rochester Medical Center, Rochester, N.Y.;