Comparative Rheology of Hyaluronic Acid Fillers, Poly-l-lactic Acid, and Varying Dilutions of Calcium Hydroxylapatite oleh Alec D. McCarthy, PhD, Danny J. Soares, MD, Akash Chandawarkar, MD, Radia El-Banna, BS, Gladstone E. de Lima Faria, MD, Nadine Hagedorn, BS