Abstract
Injections with hyaluronic acid (HA) fillers for facial rejuvenation and soft-tissue
augmentation are among the most popular aesthetic procedures worldwide. Many HA fillers
are available with unique manufacturing processes and distinct in vitro physicochemical
and rheologic properties, which result in important differences in the fillers' clinical
performance. The aim of this paper is to provide an overview of the properties most
widely used to characterize HA fillers and to report their rheologic and physicochemical
values obtained using standardized methodology to allow scientifically based comparisons.
Understanding rheologic and physicochemical properties will guide clinicians in aligning
HA characteristics to the facial area being treated for optimal clinical performance.
Keywords
aesthetics - hyaluronic acid fillers - elastic modulus - rheology