The Dynamic Nature of the Adult Skull
Contrary to the common belief that the skull is a solid, unchanging structure after adolescence, modern research shows it is constantly renewed through bone remodeling. This biological process involves osteoclasts, which resorb old bone, and osteoblasts, which form new bone. While the larger cranial vault housing the brain remains largely stable after early adulthood, the facial skeleton experiences more pronounced and asymmetrical changes. These transformations in the underlying bone structure are a key factor contributing to the visible signs of facial aging.
How Bones Remodel and Resorb with Age
The balance between bone formation and resorption is essential for maintaining bone health throughout life. As people age, this balance can shift, leading to selective bone loss in certain areas. In the facial skeleton, specific regions are more susceptible to this resorption than others. These include parts of the maxilla (the upper jaw bone), the orbital rims around the eye sockets, and the mandible (the lower jaw). The loss of bone in these areas provides a less supportive foundation for the overlying soft tissues, like skin and fat, which then sag and shift due to gravity.
Specific Age-Related Facial Bone Changes
Age-related remodeling is not uniform across the face and varies between individuals and sexes. The periorbital region, including the orbital rims, shows noticeable bone resorption, making eyes appear more sunken. In the midface and nasal area, the upper jaw tends to recede, and the nasal opening enlarges, contributing to deeper nasolabial folds and a longer-looking nose. The jawbone undergoes significant remodeling, potentially decreasing in height and length, leading to a less defined jawline and jowls. The jaw angle may widen, especially in females.
Comparison of Aging Skull Changes: Males vs. Females
A 3D computed tomography study indicates distinct sex differences in age-related skull changes. While both sexes show resorption in similar facial areas, the patterns differ. Males may show more significant overall shape changes in the cranial vault, while females might exhibit more pronounced compression in the inner frontal region.
The Impact of Lifestyle and Other Factors
Genetics play a significant role in aging, but lifestyle, nutrition, and hormonal changes also influence bone remodeling. While osteoporosis has less direct impact on the skull, factors contributing to it can affect bone density. Tooth loss significantly accelerates bone resorption in the jaw. Maintaining good nutrition and overall health supports bone structure but cannot prevent age-related changes.
Conclusion
The skull, particularly the facial bones, undergoes progressive remodeling and resorption with age, leading to changes in shape and contributing to the visible signs of aging. These dynamic skeletal changes, affecting areas like the orbits and jawline, are crucial for understanding the aging process in fields like forensic anthropology and facial rejuvenation.
What do doctors say about the skull changing shape with age?
"Corrections of the skeletal framework are increasingly viewed as the new frontier in facial rejuvenation. It currently is clear that certain areas of the facial skeleton undergo resorption with aging. These areas resorb in a specific and predictable manner with aging."
What do aesthetic experts say about the skull changing shape with age?
"As we age, the dermis—the middle layer of our skin—loses collagen and elastin... Add to that a shift in fat pads and a decline in facial muscle tone, and it's easy to see how facial features begin to look different year after year."
