RESUMEN
BACKGROUND: Face-lifting procedures are often performed to hide the effects of aging. Thread-lifting, a minimally invasive technique for the correction of facial aging, has become increasingly popular, and various materials for the procedure have been developed. OBJECTIVE: This study compared tissue responses to two types of threading sutures placed under rat skin: polypropylene (PP) monofilament mesh suspension thread (a novel face-lifting material) and polydioxanone (PDO) barbed thread. METHODS: Eight rats each were assigned to the PP monofilament mesh suspension, PDO barbed thread, and control groups. Tissue reactions were evaluated 28 days after subcutaneous loading of the materials. RESULTS: Significant increases in tensile strength and the mean area occupied by collagen fibers were evident in skin loaded with PDO barbed thread and PP monofilament mesh suspension thread compared to control skin (p<0.05). Compared to sites loaded with PDO barbed thread, those loaded with PP monofilament mesh suspension thread showed a significant increase in the number of collagen fibers and a lower grade of inflammation (p<0.05). CONCLUSION: PP monofilament mesh suspension thread has skin-rejuvenating effects comparable to those of PDO barbed thread, but induces a less severe inflammatory response. This indicates that it is a safe and effective material for use in thread-lifting procedures on aging skin.