What happens to the jaw bone when we age?

As we age, our bones naturally lose density and strength. This is a normal part of the aging process and is called bone resorption. Bone resorption is a process by which old bone is broken down and removed by cells called osteoclasts. This is followed by the formation of new bone by cells called osteoblasts. However, as we age, the rate of bone resorption increases and the rate of bone formation decreases. This imbalance leads to a loss of bone mass and strength. The jaw bone (mandible) is no exception to this process. As we age, the jaw bone can lose density and strength.

In a study comparing CT scans of a young and aged skull (pictured above), the aged skull showed the eye socket widens and lengthens, and the nose, brow and upper jaw all showed a decrease in angles. The lower jaw also decreased in length and height. You can see in the image that the jaw starts to turn into an italic “i”, when once was an “L” shape at the angle of the jaw.

In the study, they analysed CT scans of skulls in people between 20-40 years old, middle-aged people between 31 and 64, and mature people aged over 65. The same bone changes happened in both males and females, but young to middle aged females experienced bone changes earlier than men did at middle to older age.

Bone resorption means the skin, muscle and fat pads don’t have the support structure they once had and this is when the skin can show visible signs of hollowing and sagging.

Image credit: Howard Langstein/University of Rochester Medical Center.