Any lines ranging from various sizes of fine, small lines to bigger fold is due to the thinning of the skin. This reflect the loss of elastin and collagen fiber in the skin. They appears as corrugated folds.
When the wrinkle line is present only during the expression or during the facial muscle movement is called the dynamic wrinkle.
After a while, the dynamic wrinkle mat become static. This means, the wrinkle line is also present after the expression movement is over. Basically it is there all the time, or permanently.
Differently located wrinkle line is given by different name. For examole, those around the side of the eye is called the Crow’s feet Wrinkle. This is the first area for wrinkle lines to appears.
Those present on the forehead is called the frown line.
Those present between the inner side of the eyes is called the Glabellar lines.
The vertical wrinkle lines on the lips is better called the smoker wrinkle lines.
The tear trough is not really a true wrinkle. It is also called the Naso-jugal line.
The power line, or Naso-labial line is a fold rather than a wrinkle line.
The Marionnette lines is a fold.
The main causes of the wrinkle line is due to the thinning of the skin as well as the loss of fat under the skin. This is the results of aging. As the skin gets thinner, the skin get nearer to the surface of the muscle. As time goes by, this skin eventually get stuck to the underlying muscle. When the muscle contract, it pulls the skin with it causing a wrinkle line.
Please read further on the treatment here.