The science of hyaluronic acid dermal fillers

The use of injectable materials for soft tissue augmentation has been increasing, reflecting the introduction of new dermal fillers based on hyaluronic acid (HA). The physical and chemical properties of HA dermal fillers vary widely, and many variables affect their overall performance. This article explains the basic science of HA and describes how the physical properties of HA dermal fillers affect clinical outcomes. Hyaluronic acid: Describes the chemical composition of disaccharide HA monomers and how they form polymer chains and cross-link into gels for dermal fillers. Hyaluronic Acid Dermal Fillers: Explains key concepts and properties related to the production and performance of HA dermal fillers, such as degree of crosslinking, gel hardness, gel consistency, viscosity, extrusion force, HA concentration, and degree of hydration. The new formulation of HA dermal fillers recently approved by the U.S. Food and Drug Administration differs from currently available HA fillers and may be easier to extrude and last longer than previous fillers. Conclusion: Understanding the chemical and physical blueprint of HA dermal fillers may help physicians select the appropriate HA dermal filler for facial enhancement. This, together with proper syringe training and injection experience, should yield results that ultimately benefit the patient.