Wrinkles

Wrinkles are visible creases or folds in the skin. Wrinkles less than 1 mm in width and depth are defined as fine wrinkles and those greater than 1 mm as coarse wrinkles.

There are many reasons why skin wrinkles. The most common are:

Aging

Wrinkles are a by-product of the aging process. With age, skin cells divide more slowly, and the inner layer, called the dermis, begins to thin. The network of elastin (the protein that causes skin to stretch) and collagen fibers (the major structural proteins in the skin), which support the outer layer, loosen and unravel, causing depressions on the surface. With aging, skin also loses its elasticity, is less able to retain moisture, oil-secreting glands are less efficient and the skin is slower to heal. All of these contribute to the development of wrinkles.

Facial muscle contractions

Lines on the forehead, between the eyebrows (frown lines), and lines jutting from the corner of the eyes (crow’s feet) are believed to develop because of small muscle contractions. Smiling, frowning, squinting and other habitual facial expressions cause these wrinkles to become more prominent. Over time, the expressions coupled with gravity contribute to the formation of jowls and drooping eyelids.

Sun damage

Excessive exposure to ultraviolet radiation (too much sun) can result in premature aging of the skin. Premature aging of the skin is called photoaging. The ultraviolet sun rays that cause photoaging damage collagen fibers and cause the excessive production of abnormal elastin. When ultraviolet light damages skin tissue, an enzyme called metalloproteinase is produced. This enzyme creates and reforms collagen. During the process, however, some healthy collagen fibers are damaged, resulting in a disorganized formation of fibers called solar elastosis. Wrinkles develop when the rebuilding process occurs over and over, less efficiently each time.

Smoking

Healthy skin constantly regenerates. While old collagen is broken down and removed, new collagen is produced. Researchers have found that smoke causes a marked reduction in the production of new collagen. Decreased collagen results in the development of wrinkles.