Long-Term (24-Month) Safety Evaluation of Poly-DL-Lactic Acid Filler Injection for the Nasolabial Fold: A Multicenter, Open, Randomized, Evaluator-Blind, Active-Controlled Design. Issue 6 (June 2015) - No, Yeon A; Seok, Joon; Hyun, Moo Yeol; Kwon, Tae-Rin; Oh, Chang Taek; Choi, Eun Ja; Kim, Beom Joon