The method of laser hair removal is based on the Theory of Thermolysis Selective. in which the light (PHOTO) transforms heat (THERMO) destroyed (LYSIS) selectively hair follicle without damaging the surrounding tissue by means of an appropriate combination of laser wavelength, power and duration of shot.
The hair follicle consists of the following parts:
Hair follicles are dynamic structures that pass through certain cycles:
PRE-ANÁGEN PHASE: The initial growth phase. The papilla is closer to the skin surface, then move down and grow for a period of time which varies with the anatomic location. This growth of the papilla determines the length of hair.
ANÁGEN PHASE: Active state. Protein synthesis occurs in this period of rapid growth. Now is when the hair is more sensitive to thermal effects imparted from the laser light source.
CATÁGEN PHASE: It’s a state of transition. Hair growth stops..
TELÓGEN PHASE: It’s a state of rest or relaxation.
Hair Anatomy and growth cycles:
Not all of the hair is in the Anagen or Telogen phase at once, that is, although hair growth is cyclical, it isn’t synchronized. Normally 90% of hairs are in the growth phase.
The length of hair depends on the duration of the growth phase. The cycle is genetic, and how long your hair grows depends on the Anagen Phase.
As you get older the Anagen phase is going shortening and increases the rest phase, which is why it takes longer to grow in hair.
The color, hair thickness and depth are variable.
- The color depends on the content of pheomelanin and eumelonina..
- Hair thickness depends on the amount of pigments of the same. The fine hairs may have a diameter of 0,05 mm, while the beard hair can reach up 1,50 mm in diameter.
- The depth at which the hair bulb, varies by anatomical location and type, fine or thick hair.