Abstract
BACKGROUND: The 33-mg/mL hyaluronic acid (HA) formulation is a highly concentrated, cross-linked, cohesive, smooth, and completely reversible volumizing filler approved by Conformité Européene. For the first time, we aimed to evaluate the long-term efficacy and safety of the 33- mg/mL HA filler for soft tissue augmentation in the treatment of facial wrinkles. MATERIALS AND METHODS: After optimal wrinkle correction was achieved in the patients undergoing treatment by injecting the 33-mg/mL HA filler at the injection site plus one touch-up at a 2-week interval, the safety and efficacy of the filler were assessed on the 5-point Facial Volume Loss Scale through the 1-year study period. Patients were evaluated daily for 14 days and after 6 and 12 months post-treatment. RESULTS: A total of 86 subjects were treated. The mean wrinkle scores of the patients were 3.95+0.79 (range of 3-5) before treatment, 2.3+0.94 (range 1-5) six months after treatment, and 2.93+1.29 (range of 1-5) one year after treatment. Clinically significant mean wrinkle correction (P=0.001) was still evident at>12 months of treatment through 33-mg/ mL HA formulation. A clinically significant correction at>12 months after treatment was maintained by 79% of patients. Nodule formation and swelling were more frequent when the 33- mg/mL HA filler was used compared with the use of less concentrated HA fillers. One patient developed angioedema-like swelling and induration last few months. CONCLUSION: The 33-mg/ mL HA filler can provide long-term correction lasting for one year or more. Adverse effects, especially swelling and nodule formation were more common in this filler compared with less concentrated HA fillers. The side effects were correlated with the volume of the injected filler. We recommend using this concentration with low volume or combining high volume with lower concentration.