Background: The use of injectable solutions for aesthetic purposes has increased tremendously, but lacks objective support. We aimed at assessing static and dynamic effects of botulinum toxin A (BoNTA) on glabellar lines by use of an objective three-dimensional methodology.
Methods: We prospectively collected three-dimensional stereographic photographs of two different facial expressions (pretreatment, 30 and 90 days posttreatment) in 21 patients, receiving a total of 20 units of BoNTA in both corrugator supercilii muscles. The primary endpoint was the three-dimensional static and dynamic surface irregularity, and secondary endpoints were the glabellar line scale and overall patient satisfaction. Blinded retrospective data analysis and statistical evaluation were performed with p < 0.05 considered statistically significant.
Results: Static glabellar lines (neutral facial expression) were significantly reduced by - 17% and - 24% on day 30 and 90 posttreatment, respectively (vs. pretreatment; both p < 0.0001). Dynamic glabellar frown lines (firmest possible bilateral eye closure) demonstrated a reduction of surface irregularity by - 26% and - 21% on day 30 and 90 posttreatment, respectively (vs. pretreatment; both p < 0.0001). The subjective dynamic glabellar line scale documented a statistically significant improvement on day 30 posttreatment (mean ± SD: 1.5 ± 0.8; p < 0.05) versus pretreatment (2.8 ± 1.0). Polled patients confirmed a subjective wrinkle improvement 90 days posttreatment.
Conclusion: The presented setup detected even subtle changes of BoNTA treatment for facial wrinkling and is a promising asset for scientific evaluations of clinical studies analyzing the outcome and duration of efficacy of injectable solutions on the face.
Level of evidence iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
Keywords: Botox; Facial; Objective; Rejuvenation; Three-dimensional.