BACKGROUND Acne scarring occurs at a young age and causes distress for many patients. Various treatment modalities have been tried. OBJECTIVE This study investigated the efficacy of combination therapy with topical poly-lactic acid and microneedle fractional radiofrequency (MFRF) for acne scars. MATERIALS AND METHODS Patients with acne scars on both the cheeks were included. Poly-lactic acid was applied to the acne scars on one side of the face before MFRF treatment. The other side of the face was treated with MFRF and normal saline. Patients received 3 treatment sessions and were evaluated based on visual assessment and patient satisfaction. After the last treatment, objective scar assessment of scar smoothness, size, brightness, and overall improvement was performed. RESULTS Both acne scar assessment scores and patient satisfaction were better with combination therapy (p = .036 and p = .009, respectively) than with monotherapy. Combination therapy resulted in significantly better efficacy for scar smoothness (p < .001), scar size (p = .003), and overall improvement (p < .001), but not for brightness (p = .151). CONCLUSION Combination therapy resulted in significantly better clinical outcomes, including better scar smoothness and smaller scar size. Therefore, we believe this combination therapy is a safe and effective treatment for acne scars.

Background Injectable poly‐l‐lactic acid (PLLA) carries the risk of nodule or microlump formation. Various methods including sonication have been tried to minimize these adverse effects of PLLA. Aims This study investigated the change in size, distribution, and properties of PLLA particles after sonication, and the duration of sonication needed to reach the ideal particle size. Methods and Materials Two indicators, the average size of PLLA particles and diameter at 90%, were measured at each timepoint: at 0, 10, 60, 120, and 240 minutes of sonication. The characteristics and particle shape were assessed at 0 and 240 minutes. Results The average particle size and the diameter at 90% decreased drastically until 10 minutes of sonication and then increased slightly at 60 minutes. After 60 minutes, the average size and the diameter at 90% gradually decreased over time and reached 42.2 μm and 75.7 μm, respectively, at 120 minutes. After 240 minutes of sonication, the average particle size was 35.9 μm, much smaller than the smallest proper size required (40 μm). Standard deviation decreased gradually over time, which means that a more even distribution was obtained. Crystalline remnants were significantly less left with 120 minutes sonication compared to those with 120 minutes hydration only. PLLA particles were more cracked at the center, and microcrystals were more loosely distributed at the periphery after 120 minutes sonication. Conclusion Sonication help reduce the average size of PLLA particles and achieve more even distribution. Therefore, we believe sonication may attribute to the safer use of PLLA.

Background. Radiofrequency treatment improves skin aging-related concerns by promoting collagen production. However, studies of the efficacy of multifrequency radiofrequency (MFRF) are lacking. Objectives. This study aimed to analyze the efficacy of MFRF for patients with aging skin. Methods. Three MFRF treatment sessions were performed for patients with concerns about skin aging. During these sessions, MFRF was applied to the face (but not the forehead). Pores, wrinkles, subjective satisfaction, and side effects were evaluated at the first visit and 4 weeks after the last treatment. Additionally, histological and immunohistochemical evaluations of collagen, elastic fibers, and STRO-1 were performed. Results. Wrinkles and the subjective satisfaction of patients were significantly improved ( p = 0.034 and p = 0.001 , respectively). However, there was no significant effect on the number of pores ( p = 0.429 ). All side effects that occurred after treatment were tolerable and transient. Histological findings revealed thickening of collagen bundles and elastic fibers. Additionally, increases in collagen I, collagen III, and STRO-1 levels were observed using immunohistochemistry. Conclusions. MFRF treatment uses less energy than the existing radiofrequency equipment and can be an effective clinicopathologic modality for facial rejuvenation.