Did you know that facial bones continue to remodel throughout our lives, with recent research highlighting specific gender-based aging patterns? This natural process directly impacts the lower face, influencing dental health and overall appearance. We explore in detail how does the mandible change with age and what you can do about it.
The Science Behind Mandibular Remodeling
Unlike the common misconception that our bones stop changing after reaching maturity, the mandible is in a constant state of flux, driven by a process known as bone remodeling. This biological activity involves the coordinated action of two types of bone cells: osteoblasts, which build new bone, and osteoclasts, which resorb or break down old bone. With age, this balance shifts, with resorption beginning to outpace formation, especially after the age of 40 or 50.
Several factors influence this process:
- Calcium Absorption: A decline in calcium absorption as we get older means the body may pull calcium from the jawbone to supply other areas, weakening the mandible.
- Reduced Use: The jawbone needs stimulation from chewing to maintain density. Tooth loss or a reduced bite force can decrease this stimulation, leading to accelerated bone loss.
- Hormonal Changes: Decreased levels of hormones like estrogen and testosterone play a significant role in bone density loss, particularly in women.
Changes in Mandibular Dimensions
One of the most noticeable age-related changes is the overall reduction in mandibular size, which contradicts some earlier beliefs. While growth continues into adulthood, studies on mature individuals show a different trend.
Vertical and Horizontal Alterations
- Decreased Ramus Height: The vertical part of the jawbone, known as the ramus, decreases in height over time. This shortens the lower face and is more pronounced in women.
- Reduced Mandibular Body Height: The height of the jawbone's body, the horizontal part holding the teeth, also diminishes due to bone resorption in the alveolar ridge, especially after tooth loss.
- Increased Mandibular Widths: Interestingly, the mandible's width, particularly in the posterior regions like the interrami and bigonial widths, tends to increase.
- Increased Mandibular Angle: The angle at the back of the jaw becomes more obtuse (larger) with age, giving the jawline a less defined, softer appearance.
Gender-Specific Aging Patterns
Research has shown that while both sexes experience mandibular remodeling, the patterns can differ.
- Women: Tend to experience more significant bone resorption over the chin (symphyseal resorption), leading to a less defined chin contour. They also show a greater decrease in ramus height.
- Men: Exhibit more concentrated bone resorption at the gonion projection (the angle of the jaw) and alveolar ridges. The changes can result in a flattening of the jaw angle.
Impact on Oral and Facial Health
These skeletal changes have a ripple effect on both your oral function and facial appearance.
Dental Alignment and Occlusion
As the jawbone shrinks, teeth can shift and become crowded, especially the lower front teeth. This can lead to a misaligned bite (malocclusion) and create new food traps, increasing the risk of cavities and gum disease.
Bone Resorption and Tooth Loss
Bone resorption in the alveolar ridges weakens the foundation for teeth. This can cause teeth to become loose and, in severe cases, be lost entirely. For denture wearers, this shrinking jawbone can result in ill-fitting, unstable dentures, making eating and speaking difficult.
Temporomandibular Joint (TMJ) Health
Altered bite patterns and changes in the underlying bone structure can stress the temporomandibular joints, which connect the jaw to the skull. This can increase the risk of temporomandibular joint disorder (TMD), leading to headaches, jaw pain, and clicking or popping sounds.
The Visible Effects on Facial Aesthetics
The aging mandible contributes significantly to the signs of an aging lower face, often compounding the effects of soft tissue changes.
Loss of Jawline Definition
Reduced bony support in the prejowl area, combined with gravity and skin laxity, causes the overlying soft tissues to sag. This leads to the formation of jowls and a less defined jawline, a classic sign of aging.
Altered Chin Projection
With age, the chin can lose its youthful prominence. For women, broader resorption over the chin can reduce its defined contour, while for men, changes at the jaw angle may create a different profile.
Here are some of the key aesthetic implications:
- Increased Face Length: As the jaw angle increases and the chin shifts position, the lower part of the face can appear elongated.
- Sunken Appearance: The loss of bone volume, especially after tooth loss, can make the cheeks and mouth area appear sunken.
- Drooping Mouth Corners: The overall remodeling can alter the support for the lips, potentially leading to drooping at the corners of the mouth.
Comparing Mandibular Changes: Dentate vs. Edentulous
Even without tooth loss, the mandible changes. However, losing teeth significantly accelerates and intensifies the process of bone resorption.
| Feature | Dentate (with natural teeth) | Edentulous (without natural teeth) |
|---|---|---|
| Rate of Resorption | Gradual, continuous remodeling. | Significantly accelerated and intensified due to loss of chewing stimulation. |
| Alveolar Ridge | Stable, with minimal resorption if teeth are present. | Rapidly atrophies and shrinks, dramatically reducing the height and width of the jawbone. |
| Facial Aesthetics | Gradual changes like jowling and softened chin. | Pronounced sunken-in look, severely reduced lower facial height, and altered facial profile. |
| Prosthetics | Not applicable; natural teeth are present. | Required, but dentures can become unstable and ill-fitting over time. |
| Treatment Needs | Primarily preventative dental care and potential orthodontic treatment for shifting teeth. | Often require dental implants or bone grafting to restore structure and support. |
Mitigating Age-Related Mandibular Changes
While some degree of mandibular change is inevitable, several strategies can help support jaw health and minimize its impact.
Strategies to Support Mandibular Health
- Maintain Excellent Oral Hygiene: Regular brushing, flossing, and professional dental checkups are crucial for preventing gum disease and tooth loss, which are major contributors to bone loss.
- Address Tooth Loss Promptly: Replacing missing teeth with dental implants is highly recommended, as they provide the necessary stimulation to the jawbone to prevent further resorption.
- Ensure Adequate Calcium and Vitamin D: Both are essential for bone density. Consult a healthcare professional about supplements if your dietary intake is insufficient.
- Manage Underlying Health Conditions: Conditions like diabetes and heart disease can increase the risk of oral health problems and, consequently, jawbone issues.
- Consider Orthodontic Treatment: For shifting teeth, adult orthodontics like clear aligners can realign your bite and reduce abnormal wear patterns.
Conclusion: Proactive Care for a Healthy Jawline
The aging mandible is a complex, dynamic process involving bone resorption and remodeling that can significantly alter oral health and facial aesthetics. Understanding how these changes manifest, particularly the differences between men and women and the impact of tooth loss, is the first step toward proactive care. By focusing on preventative measures, addressing dental issues promptly, and adopting a comprehensive approach to health, you can support your jawbone and maintain a healthier, more vibrant-looking face for years to come. For more detailed clinical information on facial aging, consider visiting the National Institutes of Health website.
