Effectiveness and Safety of a Polycaprolactone-Based Dermal Filler for Correction of Temple Hollowing in Chinese Adults: A Multicenter Randomized Controlled Study

Abstract Background Temple hollowing is a common sign of facial aging. Evidence for durable correction with polycaprolactone (PCL)-based dermal fillers in this indication remains limited. Objectives To evaluate the effectiveness and safety of a PCL-based dermal filler for correction of flat to severe temple hollowing in Chinese adults. Methods In this prospective, multicenter, randomized, evaluator-blinded trial, subjects with Allergan Temple Hollowing Scale (ATHS) scores of 1-4 were randomized 2:1 to receive bilateral filler injections or no treatment. Optional touch-up was allowed at Month 1. The primary endpoint was the blinded investigator-assessed ATHS response rate at Month 12 after the last injection or randomization, defined as a ≥ 1-point bilateral improvement from baseline. Secondary endpoints included GAIS improvement, subject satisfaction, injection investigator-assessed ATHS response, and third-party blinded panel photographic assessment. Safety was monitored. Results 161 subjects were randomized. The ATHS response rate was higher in the treatment group at Month 12 (90.6% vs. 0.0%). Efficacy was maintained through Month 18 in the treatment group, with sustained aesthetic improvement and high subject satisfaction. GAIS improvement exceeded 94% at all visits. No serious treatment-related events were reported. Conclusions This PCL-based dermal filler demonstrated significant and durable improvement and was well tolerated for correction of flat to severe temple hollowing in Chinese adults through 18 months.