This skull shows the unmistakable appearance of osteoporosis, which has resulted in loss of bone from the skull, particularly around the jaw where the teeth should be present. The patient was ‘an aged, bedridden female’ according to the contemporary notes, who had suffered from generalised loss of bone mass from all the major bones of her skeleton. Especially observable in the skull, this loss of bone had left her without teeth and the loss of the normal mass and detail of the jaw bones. In osteoporosis there is loss of bone tissue, both the matrix and the calcium that it contains. The bone consequently becomes either entirely lost as seen in the detail of the jaws here or thinned and weakened in the longer bones, pre-disposing to fracture. This is a special problem in older women as a consequence of hormonal changes but it also occurs in males as they age.
The above image shows the micro-architecture of normal bone on the left and in osteoporotic bone on the right; the loss of bone is clearly seen. Osteoporosis arises in the elderly as a result of a decrease in the numbers of osteoblast cells, the cells that make bone. There is a constant turnover of bone with a balance between bone being destroyed and bone being remade; the diminution in osteoblast numbers mean there is a deficit in bone formation so on balance there is bone loss. The female hormone oestrogen is essential for healthy bones and so after the menopause, when oestrogen levels fall, there can be a rapid decrease in bone density in women. Osteoporosis is present in about 15% of those 50–59 years of age, but these figures increase rapidly to about 70% of those over 80 years of age. Exercise and a balanced diet increase bone density in early life, so a healthy lifestyle can help to prevent later osteoporosis.