A Single Center, Prospective, Randomized, Sham Controlled, Double Blind, Split Face Trial Using Micro-injections of Transparent Hyaluronic Acid Gel (Restylane® Silk) for Rejuvenation of the Aging Cheek

Soft tissue augmentation with injectable hyaluronic acid (HA) is a well-established modality for the correction of facial volume loss, fat atrophy, fine lines, and wrinkles. HA is a glycosaminoglycan that is composed of repeating D-glucuronic acid and D-N-acetylglucosamine disaccharide units. Because HA is a natural and inert constituent of the dermis, it represents an ideal substance for soft tissue augmentation. Current FDA-approved HA fillers are typically utilized to either directly target specific cutaneous rhytids or to restore overall contours by placement into fat pads or along bony structures that have remodeled with age. Restylane® Silk is a transparent injectable HA gel that received FDA approval in June 2014 for use in the lips and peri-oral region. Its unique synthesis results in smaller and finer particles that demonstrate significant hygroscopic properties and give rise to the potential for unique applications. One such application concerns the concept of "skin boosting" whereby microaliquots of HA are placed into the skin to induce biophysical improvement in dermal characteristics (1). Using this technique, a recent split-body study by Streker et al. demonstrated significant aesthetic improvements in face, hands and décolletage (2). However, there have been no well-controlled studies with validated aesthetic outcomes utilizing Restylane® Silk in this fashion to date. Because of the unique combination of ultra-fine product and high water-attracting capability, the investigators hypothesize that microinjections of Restylane® Silk can be used in a grid-like injection pattern for rejuvenation of the aging cheek.