The skin is a complex organ that aging results from intrinsic factors (which depends mainly on our genetic capital) but also of extrinsic factors (sun exposure, diet, lifestyle)
The dermis, epidermis and skin aging
Human skin is a full-fledged body that consists of three layers:
The epidermis is the outermost layer, itself made up of several layers of dead hardened cells (keratinocytes, hardened because rich in keratin fibers that are found in our nails and our hair). Its main function is to protect our skin against assaults from the external environment (bacteria, pollution, UV, etc.).
The hypodermis, fatty layer at both the deepest and thickest of our skin that contains adipocytes, variable thickness on the basis of our food habit.
Between these two layers is the dermis, five to ten times thicker than the epidermis, within which several cell types coexist, among which:
-Langerhans cells that provide the immune system
-The Melanocytes, which produce melanin (which colors our skin)
-Fibroblasts producing collagen and elastin
All of these cells are bathed in a kind of "support frame" called extracellular environment whose main constituents are:
-Collagen: major component of our body (we are composed more than 90%!)
-Fibre elastic, expandable, providing the extensibility of the skin by participating in its skin maintenance at rest.
-Hyaluronic acid which gives our skin's hydration and volume properties
The formation of wrinkles
Over time and under the action of many external causes or extrinsic factors (such as prolonged exposure to radiation from the Sun, pollution, poor diet) and that under the action of our organization-specific or intrinsic factors (fall of the production of certain hormones during menopause, specific genetic programming, events in life such as infections or diseases) occurs skin aging including one of clinical translations is the formation of our wrinkles.
These correspond to a real "face" of the dermal layer, which is the skin. This phenomenon is also called the dermatoporosis (comparable to post-menopausal osteoporosis). All components of the DermIS are met:
-It results in loss of hyaluronic acid, therefore a loss in water at the level of the DermIS which translates clinically by a dry skin
-The elastic fibers are also scarce and are replaced by less extensible collagen. Deprived of its elastin, the skin will be more difficult to regain its original shape after deformation and will keep in memory all the foldings it will suffer (as opposed to a skin of child).
-Collagen disappears it also gradually (from the age of 40 it loses 1% per year) and will tend to rigidify via a phenomenon called glycation.
Thus, the skin will lose little by little its suppleness and hydration
All these phenomena will lead to a kind of "dermal divide" that will be the basis for the formation of the ride that can be observed on a face aging when it is in a "static" position.
Dynamic wrinkles are also appearing in the third decade, leaving frontal wrinkles, the Crow's feet wrinkles or wrinkles of the lion.
Static wrinkles can be treated by injections of fillers (radiesse or hyaluronic acid).
The expression wrinkles (or dynamic) will be supported with injections of botulinum toxin.