What makes us look older? Wrinkles and sagging result not just from changes in the skin, but also from aging-related changes in the underlying facial bones, according to a report in the January issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).
Led by Dr. Robert B. Shaw, Jr., of University of Rochester Medical Center, the researchers analyzed computed tomography scans of the facial bones in young (age 20 to 40), middle-aged (41 to 64), and older (65 and up) age groups. All scans were performed for medical reasons—not for planning plastic surgery.
Aging Linked to Changes in Eye Sockets, Jaw Bones, and More
Detailed measurements in three-dimensional reconstructions of the CT scans showed some important differences in the facial bone structure (or facial skeleton) between age groups. "The facial skeleton experiences morphologic change and an overall decrease in volume with increasing age," Dr. Shaw and colleagues write.
One prominent change was an increase in the area of the "orbital aperture"—that is, the eye sockets. In both men and women, the eye sockets became wider and longer with age. Aging also affected the bones of the middle part of the face, including reductions in the glabellar (brow), pyriform (nose), and maxillary (upper jaw) angles.
The length and height of the mandible (lower jaw) decreased with age as well. Although these changes occurred in both sexes, many occurred earlier in women—between young and middle age. In men, most of the changes occurred between middle age and old age.
Plastic surgeons are experts at dealing with changes in the skin and underlying soft tissues that contribute to an aged appearance of the face. However, as the new study demonstrates, they must also understand the contribution of changes in the underlying facial bones.
"The bony components of the face are important for overall facial three-dimensional contour as they provide the framework on which the soft-tissue envelope drapes," Dr. Shaw and coauthors write. For example, the enlarging eye socket and decreasing brow angle could contribute to frown lines on the forehead, "crow's feet" at the corners of the eyes, and drooping of the lower eyelid.
By using materials and techniques for skeletal augmentation, plastic surgeons can improve the outcomes of facial rejuvenation, Dr. Shaw and colleagues believe. They discuss the "aesthetic implications" of changes in the facial bone structure, and outline some strategies plastic surgeons can follow to optimize the final results for patients who desire a more youthful appearance.
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