Radio frequency energy is a form of electromagnetic energy. Radio frequency current through tissue will generate heat in the tissue. This source of heat has extensively been used in surgery for hemostasis and tissue ablation (electro-surgery), but more recently it has been applied as a means of shrinking redundant or lax connective tissues through the mechanism of collagen denaturation. Collagen molecules are produced by fibroblasts. Heated fibroblasts are also implicated in new collagen formation and subsequent tissue remodeling which can also contribute to the final clinical result. The precise heat-induced behavior of connective tissues is dependent on several factors which include the maximum temperature reached, exposure time, tissue hydration, and tissue age.