The Dynamic Nature of the Adult Skull
While the adult skull is often perceived as static, it's a dynamic part of the skeleton with ongoing, subtle remodeling processes. This involves the removal of old bone and formation of new bone. These changes are usually slow and unnoticeable, but various factors can lead to more significant alterations.
Aging and Bone Remodeling
Aging affects bone remodeling throughout the body, including the face and skull. Facial bones continue to change with age. The eye sockets may enlarge due to bone resorption, contributing to a sunken appearance. The jawbone and upper jaw also change, particularly with tooth loss, affecting facial profile. Additionally, changes in cartilage in the nose and ears, along with shifts in facial fat and skin elasticity, can create the perception of altered head shape.
Medical Conditions Affecting Skull Shape
Certain medical conditions can cause more noticeable skull shape changes.
- Paget's Disease of Bone: This disorder disrupts bone renewal, leading to enlarged, misshapen, and brittle bones. If it affects the skull, it can cause head enlargement.
- Acromegaly: Excess growth hormone can cause thickening of bones and soft tissues, resulting in a more prominent jaw and brow ridge, rather than outright skull expansion.
- Hydrocephalus in Adults: In adults, excess cerebrospinal fluid increases intracranial pressure but doesn't enlarge the skull; it can damage brain tissue.
- Cancer: Cancers affecting bone, like multiple myeloma, can cause skull irregularities.
- Gorham's Disease: This rare condition involves bone loss and can lead to skull indentations.
The Impact of Trauma and Force
Trauma can directly alter skull shape. Fractures can leave permanent indentations. Chronic forces, like chewing patterns, can subtly influence facial bone structure over time.
Differentiating Perceived vs. Actual Change
Changes in soft tissue, not the skull itself, often create the perception of altered head shape. Weight gain, fluid retention, or hair loss can make the face or scalp appear fuller or larger.
Diagnosis and When to See a Doctor
Rapid or painful skull shape changes warrant medical consultation. Imaging tests can help determine the cause. Early diagnosis of conditions like Paget's disease or acromegaly is important for management.
Comparison of Conditions Causing Skull Change
| Feature | Paget's Disease of Bone | Acromegaly |
|---|---|---|
| Cause | Disrupted bone renewal. | Excess growth hormone. |
| Onset | Age 50+. | Gradual. |
| Affected Areas | Skull enlargement, hearing loss. | Thickened features, prominent jaw. |
| Diagnosis | Blood tests, imaging. | Hormone levels, MRI. |
Conclusion
Most perceived changes in adult skull shape are due to normal aging processes affecting facial bones and soft tissues. However, certain medical conditions or trauma can cause significant changes. Monitoring changes and seeking medical advice for rapid or painful alterations, especially with other symptoms, is crucial. For more details on age-related facial skeleton changes, see the research in Nature.
