Indirect effects of hyaluronic acid applications on the glabella and nasolabial regions: An anatomic evaluation

This study is among the first to systematically evaluate the indirect anatomical effects of hyaluronic acid injections on the glabellar and nasolabial regions. It focuses on changes in wrinkle severity and anatomical parameters to enhance safety and efficacy. In this study, we analyzed pre- and post-treatment photographs of 31 women with a mean age of 45.97 ± 7.10, who received hyaluronic acid treatment. The study was designed retrospectively. Photographs taken before the procedure and one month after treatment were obtained from the clinical archive. Digital anatomical measurements were performed on these images. The anatomical measurements focused on the glabella (including facial convexity, total facial convexity, and facial concavity) and the nasolabial regions (including nasolabial and nasolabial fold angles on both the right and left sides). Wrinkle Severity Rating Scale (WSRS) evaluations were also conducted for both the glabella and nasolabial folds. Evaluations were performed by analyzing photographs taken before, 4 weeks after, and 12 weeks after hyaluronic acid filler application. In the glabellar region, hyaluronic acid injections into the temporal and zygomatic areas significantly reduced wrinkles, especially 12 weeks post-treatment (P = .004), indicating an indirect improvement in glabellar wrinkles. A positive correlation between age and wrinkle improvement was found (r = 0.601, P = .000), suggesting more pronounced effects in older individuals. In the nasolabial region, significant reductions were observed in both the right (P < .001) and left (P < .001) nasolabial folds post-treatment, with age also correlating with improvement (right: r = 0.693, P = .000; left: r = 0.496, P = .005). The S300 and S500 formulations reduced wrinkles, with the S500 showing greater efficacy than the S300. The findings of our study suggest that hyaluronic acid fillers can indirectly reduce the depth of nasolabial folds, and this effect can be achieved particularly when applied using techniques that are suitable for anatomical and vascular structures. This approach may be considered a viable alternative in aesthetic procedures, as it has the potential to enhance treatment safety by reducing the risk of complications associated with direct interventions.