It's not just wrinkles that reveal age. A new study finds that changes in bone structure make faces look older, too.

While scientists had known there are general bone changes with age, such as bone thinning, this study is the most detailed look at such alterations.

Using computed tomography (CT) scans, researchers analyzed the facial bones of men and women across different age groups. The structure of the bones differed between age groups, the researchers reported in the January issue of the journal Plastic and Reconstructive Surgery. These changes could influence the way skin and muscle tissue sit on the bones, contributing to an aged look.

"Physicians have long been taught that facial aging is caused by soft tissue descent and loss of elasticity," study researcher Howard Langstein, the chief of plastic and reconstructive surgery at the University of Rochester Medical Center, said in a statement. "Though we have always known that bones change over time, until now, the extent to which it causes an aged appearance was not appreciated."

Langstein and his colleagues analyzed CT scans of 60 female and 60 male patients' faces. (CT images are created using X-rays.) All of the original scans were done for medical reasons, not as preparation for plastic surgery. The patients were split into three age groups: young (ages 20 to 40), middle-aged (41 to 64) and older (65 and up).

Bones undergo a number of changes with age, the researchers found. In both men and women, the eye sockets became wider and longer. The distance between the most prominent part of the brow to the top of the nose decreased, while the cheekbones stuck out less and the opening of the nose bones receded. Meanwhile, the lower jaw shrunk in both length and height.

The changes in eye-socket size and shape may contribute to forehead wrinkles and crow's feet, the researchers wrote. A decrease in jaw size could flatten the chin and soften the neckline, while changes in nose bones could lead to "decreased nasal support and projection," the researchers reported.

Previous studies have found that facial bones lose volume with age, the researchers wrote. Women showed the changes slightly earlier than men, the study showed. That makes sense since women tend to lose bone tissue faster than men because of menopause-related changes.

This being a plastic surgery journal, the researchers had some cosmetic solutions: Fat grafting to plump up the face and skeletal implants to shore up shrinking bones. But if that all sounds a bit too invasive, you might try an ounce of prevention instead. Research shows that the best way to look (and feel) youthful is to avoid cigarettes, wear sunscreen, and strengthen your bones with exercise.