Aging skin droops and develops wrinkles, lines and furrows. The severity of these changes in an individual depends on genetic tendency, skin phototype and exposure to environmental factors. Facial lines and wrinkles form because of the following factors: aging process, sun damage, muscle movement, smoking, and gravity. The main culprits are sun damage due to sun exposure and exposure to environmental toxins such as tobacco smoke.
There is often a degree of asymmetry to the lines, as people tend to smile or frown more on one side than the other, or consistently sleep on the right or the left cheek. Fine lines and wrinkles arise because of irregular thickening of the dermis and because of a decrease in the amount of water held by the epidermis.