Contemporary review of injectable facial fillers.

Perhaps the most significant change in facial rejuvenation in the last 10 years has been the introduction of nonsurgical treatments for the relaxation of facial wrinkles and for the restoration of lost volume. Fillers such as paraffin and silicone have been used in the past for volume restoration, but only recently have new fillers been developed whose safety and efficacy have been supported by clinical research. The introduction of hyaluronic acid (HA) fillers in 2003 began the filler revolution and paved the way for development of biostimulatory and permanent materials. There is an abundance of high-level evidence-based studies comparing the HA fillers, calcium hydroxylapatite, and poly(methyl methacrylate) with collagen and other HA formulations, but there is only limited high-level data evaluating poly-L-lactic acid.