RESUMEN
BACKGROUND: Hyaluronic acid (HA) fillers are the most commonly used fillers for soft-tissue augmentation. The face is a dynamic structure. Facial rejuvenation by filler products depends on mechanical forces on the region of the face. The successful use of injectable HA fillers requires an understanding of the options available. OBJECTIVE: The purpose of this study is to measure the rheological properties of HA fillers and to clarify how to select these fillers considering their rheological properties. MATERIALS AND METHODS: Rheological characterization was performed on 41 fillers. Physical parameters directly linked to product performance were measured. RESULTS: The properties of the HA fillers varied. These findings provide a basis for selection guideline regarding rheological properties in facial rejuvenation. CONCLUSION: The authors' report is the largest study to determine the rheological properties of HA fillers to date. Understanding the fillers' properties can help physicians select the appropriate fillers for more predictable and sustainable results.