Objective Analysis of Poly-L-Lactic Acid Injection Efficacy in Different Settings

BACKGROUND Poly-L-lactic acid (PLLA) filler is known to have continuous volume effect. OBJECTIVE The objective of this study is to analyze objective volume effect of PLLA in different settings of injection schedule on the cheek. METHODS A split-face, evaluator-blind randomized study in 24 volunteers was conducted. One side was injected 3 times with 4 cc dose and the other side was injected 2 times with 6 cc dose per visit. Facial volume loss scale (FVLS) and Vectra were evaluated. RESULTS Measured average FVLS showed statistically significant improvement both in 3 and 2 times injection sides and maintained efficacy until 12 months. Vectra showed volume difference (cc) between before and after injection. In 3 times injection side, it was increased 2.12 (after 1 month) to 3.17 (after 12 months). In 2 times injection side, it was increased 2.26 (after 1 month) to 3.19 (after 12 months). Gradual volume improvement over 12 months was statistically significant in both sides. There was no statistically significant difference between 3 and 2 times injection in FVLS and Vectra. There was no severe adverse event. CONCLUSION Poly-L-lactic acid has continuous volume effect and there was no significant difference by injection times at the same total injection volume.