skin. Skin wrinkles typically appear as a result of agingprocesses
such as glycation, habitual sleeping positions, loss of body mass, or
temporarily, as the result of prolonged immersion in water. Age
wrinkling in the skin is promoted by habitual facial expressions,
aging, sun damage, smoking, poor hydration, and various other factors.
Causes for aging wrinkles
Development of facial wrinkles is a kind of fibrosis of the skin.
Misrepair-accumulation aging theory suggests that wrinkles develop
from incorrect repairs of injured elastic fibers and collagen fibers.
Repeated extensions and compressions of the skin cause repeated
injuries of extracellular fibers in derma. During the repairing
process, some of the broken elastic fibers and collagen fibers are not
regenerated and restored but replaced by altered fibers. When an
elastic fiber is broken in an extended state, it may be replaced by a
"long" collagen fiber. Accumulation of "long" collagen fibers makes
part of the skin looser and stiffer, and as a consequence, a big fold
of skin appears. When a "long" collagen is broken in a compressed
state, it may be replaced by a "short" collagen fiber. The "shorter"
collagen fibers will restrict the extension of "longer" fibers, and
make the "long" fibers in a folding state permanently. A small fold,
namely a permanent wrinkle, then appears.
