There are varying amounts of fat at different parts of our face. Fat volume loss (superficial and deep) is consistent with ageing. Collagen and elastin levels, too, begin to decrease and the condition of the skin is affected.
In some cases, the facial muscles may begin to atrophy. The rate of bone resorption increases with age and is the main reason for the change in structure of facial bones and the facial appearance. The volume of facial bones decreases with age, too.
These factors change the underlying structure of the face and may cause the cheekbones and mid-face to look collapsed.