Hyaluronic acid-based fillers properties and its importance in the practice of Orofacial Harmonization

Injectable fillers based on hyaluronic acid are now frequently used to correct tissue volume loss when facial rejuvenation is sought. The way in which these commercially available HA fillers are manufactured has direct implications for the properties of the gel and the clinical applications of these products. These properties can be described using the science of rheology, which describes the flow and deformation of matter, allowing researchers to understand how these fillers act under mechanical stress, either at the time of injection or after implantation of the gel. It is important to note that the mechanical forces exerted on each anatomical region of the face vary in intensity and frequency, causing the filler to deform in different ways. The aim of this study was to review the literature on the rheological properties of hyaluronic acid gels and to emphasize the importance of knowing these properties when selecting fillers, so that harmonizing professionals can achieve the desired results.