When any wound is created, whether traumatically, or surgically, there is a wound healing cascade that is initiated. Multiple things occur underneath the skin that are not visible to the naked eye. An infantile form of collagen is first formed and then as the wound matures, the body dissolves that collagen and lays down a mature form of collagen. Then this collagen over many months integrates in a stronger formation, similar to pick up sticks falling on the ground and then someone laying them neatly together in parallel groupings. Inflammatory cells are also recruited into the area to keep it clean and new blood vessels form, microscopically, to bring in more oxygen that is needed for the new collagen to form.Typically there are biochemical and clinical changes in healing scars that are seen even up to 18 months after surgery, but this is why with Fraxel, that there is continual improvement in collagen build-up and even tightening possibly, for six months.