CHSU Discovery

Abstract

• Soft tissue fillers are the second-most performed non-surgical aesthetic procedure globally, with ~4.9 million procedures in 2022, and dermatologists are the leading providers.1,2,3
• Fillers are injectable biomaterials used to reduce facial lines, restore volume, and enhance contour. Commonly used types include hyaluronic acid, poly-L-lactic acid, calcium hydroxylapatite, and polymethylmethacrylate, each acting via physical or bio-stimulatory mechanisms.4
• As filler use grows, understanding host-material interactions is critical. Tissue responses vary by filler type, host biology, and time since injection, and can range from intended therapeutic effects to adverse outcomes including hypersensitivity reactions, granulomas, and nodule formation.5,6
• Current evidence on filler-tissue interactions is fragmented across studies and case reports. This scoping review maps the literature, synthesizes findings across filler types, and provides the biochemical and histopathological context to guide clinical use of fillers.