Nonablative Radiofrequency Technology

The latest device to be initiated for non-ablative skin treatments involved radiofrequency (RF) technology. Unlike laser or light sources, which generate heat when selective targets, such as microvasculature, absorb photons, the radiofrequency device delivers an electric current that nonselectively generates heat by the tissue’s natural resistance to the flow of ions.As melanin absorption is not an issue, this RF device can be safely applied regardless of skin type. Radiofrequency technology has previously been used for aesthetic cutaneous surgery, albeit for a limited time and with equivocal results. High frequency, low voltage energy was delivered through conducting media for epidermal ablation (cold ablation) [69,70]. Reconfiguration of this technology resulted in the ThermaCool TC^TM System (Thermage, Inc., Hayward, CA), which has a unique treatment tip with a coupled electrode design that allows for uniform volumetric heating of the deep dermis. To prevent epidermal ablation, cryogen spray cooling is delivered prior to, during, and after the emission of radiofrequency energy. Heating of the deep dermis and subcutaneous tissue occurs; with the depth determined by treatment tip geometry and the impedance levels in varying tissues (as opposed to wavelength with laser irradiation). Heat-induced collagen denaturation and contraction account for the immediate skin tightening seen after treatment [67].As with all other non-ablative devices, further neocollagenesis takes place over the ensuing months, effecting further reduction of rhytides and tissue tightening [71–74] . Periocular rhytides and brow rhytides have shown significant improvement after a single treatment, as have cheek and neck laxity [71–74]. Maximal clinical results are observed 3 to 6 months after treatment and additional treatments can be applied for additive effect [74].