For this study, a minimally invasive bipolar RF device (INNOfill; Pacific Pharma, Seoul, Korea; 1∼2 MHz, power range 0∼23 W) with 21-, 27-, or 30-gauge RF needle electrodes in combination with a patch-type electrode was evaluated (Fig. 1A). The entirety of the RF needle was insulated with a biocompatible parylene layer except the distal 1 mm, which remained exposed to act as the electrode in the tissue. A separate RF needle, specifically designed to deliver RF, was also injected into the skin to create an autologous containment collagen canal to extend the in vivo half-life of the filler (Fig. 1). The procedural protocol for the INNOfill is briefly summarized in Fig. 1B.