INTRODUCTION
As the aging population in our society continues to increase, many people are seeking technologies and treatments to help achieve a more youthful appearance. This, coupled with the general population’s busy lifestyle, is leading towards a desire for procedures with minimal side effects and little to no recovery time. Of the skin rejuvenation modalities, radiofrequency (RF) has emerged as a safe and effective treatment for a broad range of aesthetic and medical indications.1-4
Radiofrequency emits focused electromagnetic waves which meets resistance within the tissue, generating heat.5 This thermal energy affects collagen’s triple helix structure, subsequently breaking the intramolecular hydrogen bonds resulting in immediate collagen contracture and subsequent neocollagenesis within the dermis without disrupting the epidermis.6-8 This results in further collagen tightening and an overall increase in collagen content.9 A study by el-Domyanti et al10 shows that RF further decreases elastotic material in the upper dermis and induces reorientation of elastic fibers within the papillary and upper reticular dermis. Unabsorbed by melanin, RF is chromophore independent allowing it to be safely used for all skin types.11 RF is associated with few complications and adverse effects while allowing a quick recovery time.12-14
RF devices vary based on the number of electrodes, dividing them into unipolar, bipolar and multipolar devices. Unipolar devices have a single electrode with a grounding pad. The highest concentration of electrical energy, and consequently heat, remains near the tip of the electrode and decreases distally.15 This type of device results in the deepest tissue penetration resulting in the highest efficacy,5 though it is accompanied with significant discomfort16,17 Unipolar devices have shown significant improvements in skin tightening and laxity, rhytids, brow elevation and both active and scarring acne lesions.9,10,13,16,18-21 Furthermore, the use of a mobile device for the delivery of unipolar radiofrequency in a split face study has shown a trend toward improvement of rhytides and laxity of facial skin.55
Bipolar devices consist of two electrodes, without a grounding pad, emitting a fast, alternating current.15 The controlled energy distribution decreases the discomfort associated with older devices.22-24 The main limitation of this device is that the treated area is limited to the volume between the two electrodes25 with the depth of penetration being approximately half the distance between the two electrodes.26
Lastly, multipolar devices work similarly to the bipolar ones but consist of three or more electrodes. One electrode maintains a positive charge while the others carry negative charges. Electrodes alternate between positive and negative charges to avoid overheating.15 These devices allow a larger volume to be heated with less discomfort, although only superficial areas are treated.23,24
Popular approaches to radiofrequency therapy involve combining treatment modalities allowing for enhanced efficacy and reduced adverse effects. Several devices have been combined with RF including broadband light, lasers, ultrasound, pulsed electro-magnetic fields, and vacuum devices. Combining differing mechanisms of action leads to complimentary effects.
New Indications
A myriad of studies have been conducted expanding indications for the use of radiofrequency devices and discovering the underlying mechanisms resulting in their efficacy. Identifying
