RESUMEN
BACKGROUND: Beside botulinum-toxin injections and hyaluronic acid fillers, thread lifts have established themselves as the third column of minimally invasive facial rejuvenation. Most commonly, barbed threads for this approach are made out of polydioxanone, a material known for decades from application in resorbable sutures. The clinical efficacy and the putative material safety of polydioxanone have fueled the popularity of thread lifts. METHODS: The present study highlights significant variation among six commercially available threads in microstructure, tensile strength, elasticity, anchoring capacity in human tissue, and biocompatibility. RESULTS: Despite their license to be marketed and sold in the European Union, some products performed significantly worse than others on material testing, and even displayed cytotoxic characteristics. CONCLUSION: The results of this study are highly relevant for clinicians and may be linked to various typical side effects of polydioxanone threads for facial rejuvenation.