The paper "What are filling (volumizing) threads?" by Kyu-Ho Yi explores the evolution and advancements in PDO volumizing threads, which have become increasingly important in facial rejuvenation as skin elasticity declines with age. The author traces the historical development of these threads, from early attempts with fine monofilaments to modern innovations that address tissue deformation and maintain thread integrity post-insertion. The paper categorizes volumizing threads based on their elasticity, shape, and functionality, highlighting their versatility in correcting wrinkles, sculpting contours, and restoring facial volume. Key mechanisms and effectiveness of these threads are discussed, emphasizing the importance of selecting appropriate thread characteristics to achieve optimal outcomes while minimizing complications. The paper also provides recommendations for future research, including long-term safety assessments and patient-specific outcomes, to enhance the clinical utility and applicability of volumizing thread procedures.The paper "What are filling (volumizing) threads?" by Kyu-Ho Yi explores the evolution and advancements in PDO volumizing threads, which have become increasingly important in facial rejuvenation as skin elasticity declines with age. The author traces the historical development of these threads, from early attempts with fine monofilaments to modern innovations that address tissue deformation and maintain thread integrity post-insertion. The paper categorizes volumizing threads based on their elasticity, shape, and functionality, highlighting their versatility in correcting wrinkles, sculpting contours, and restoring facial volume. Key mechanisms and effectiveness of these threads are discussed, emphasizing the importance of selecting appropriate thread characteristics to achieve optimal outcomes while minimizing complications. The paper also provides recommendations for future research, including long-term safety assessments and patient-specific outcomes, to enhance the clinical utility and applicability of volumizing thread procedures.