The Dynamic Nature of the Cranial Skeleton
While a common misconception is that the adult skull is static, it is in fact a dynamic structure that undergoes continuous remodeling throughout life. This process involves the constant cycle of bone resorption (breakdown) and bone deposition (formation). The delicate balance of this cycle is influenced by a number of factors, including hormonal changes, biomechanical forces from chewing, and overall health. As we age, this balance shifts, leading to asymmetrical and site-specific changes in the bone structure that dramatically alter the face's appearance over time.
Specific Changes in the Lateral Skull View
The Forehead and Supraorbital Rim
Contrary to the recession seen in the lower face, the forehead actually undergoes expansion as we age. Bone deposition on the external surface of the frontal bone, particularly the supraorbital rim, causes the forehead to expand and protrude. This can alter the angle of the forehead and contribute to a change in the overall facial profile when viewed from the side.
The Midface and Zygomatic Bones
The midface is one of the most susceptible areas to age-related bone changes, primarily through resorption.
- Maxillary Retreat: The maxilla, which forms the midfacial skeleton, experiences significant bone resorption, causing it to lose projection and appear to retract. This loss of support is a major contributor to the deepening of nasolabial folds.
- Zygoma Recession: The zygomatic bones, or cheekbones, also undergo resorption. From a lateral perspective, the zygoma becomes more retropositioned with age, with an increasing angle between the bone and a vertical line. This contributes to the loss of midface volume.
Orbital Expansion and Eye Socket Changes
Studies consistently show that the orbital aperture, or eye socket, enlarges with age. However, this resorption is not uniform. The most significant bone loss occurs at the superomedial and inferolateral aspects of the orbital rim. This uneven expansion leads to several notable changes:
- Sunken Appearance: The increased orbital size can make the eyeballs appear more sunken.
- Eyelid and Brow Changes: Resorption contributes to the apparent droop of upper eyelids and lengthening of the lid-cheek junction.
The Mandible and Chin
The lower jaw also undergoes significant transformations visible from the side. These changes are particularly pronounced in older age, especially with tooth loss.
- Widening of the Mandibular Angle: The angle of the mandible becomes more obtuse (wider) with age, a change resulting from resorption of the inferior border of the jaw.
- Chin Recession and Shortening: The chin often becomes shorter and more oblique with age due to continued bone remodeling and resorption. This reduces its vertical projection.
- Tooth Loss Impact: The absence of teeth leads to further atrophy of the alveolar processes, accelerating the reduction in mandible size.
The Nasal Profile
Changes to the piriform aperture, the bony opening for the nasal cavity, also impact the lateral profile. The aperture widens with age as the bone around its edges resorbs. Furthermore, the anterior nasal spine, which supports the nose's tip, recedes. This weakens support for the nose's cartilage, causing the nasal tip to droop and the nose to appear longer and wider.
Comparison of Youthful vs. Aged Lateral Skull View
To illustrate the cumulative effect of these changes, consider the contrast between a younger and older skull from a lateral perspective. Changes in the Facial Skeleton With Aging provides excellent visualization of these differences.
| Feature | Younger Skull (Lateral View) | Older Skull (Lateral View) |
|---|---|---|
| Forehead | Softer, less prominent projection | Expanded, more prominent due to bone deposition |
| Midface Projection | More prominent and convex | Retreats and flattens due to maxillary resorption |
| Orbits | Smaller, rounder appearance | Enlarged, with uneven resorption at rims |
| Mandibular Angle | More acute, sharper angle | Wider and more obtuse, angle increases |
| Nasal Tip | Supported by more robust nasal spine | Droops and rotates downward as support recedes |
| Chin | Defined, with more vertical height | Shorter and more oblique, with less vertical projection |
Conclusion: A Shift in Foundation
The skeletal changes observed from the lateral view are not random; they follow predictable patterns of resorption and deposition that occur throughout the aging process. The expansion of the forehead combined with the retraction of the midface and mandible fundamentally shifts the facial foundation. This bony remodeling directly influences the overlying soft tissues, contributing to the development of facial features commonly associated with old age. These changes are a core component of the complex, multilayered process of human aging.
