Investigating the Clinical Merit of Contraction Patterns for Glabellar Neuromodulator Injections—A Clinical Retrospective Investigation Following the 3-Point Glabellar Injection Technique

Abstract

Background: Since the introduction of glabellar contraction patterns as a guide for neuromodulator treatments, feedback regarding its clinical utility has been mixed. Recent studies have cast doubt on the value of such contraction-pattern-driven treatment paradigms. Objective: The aim of this retrospective study is to evaluate the clinical outcome of identical glabellar injections independent of glabellar contraction pattern types. Methods: Forty-two Brazilian, multi-ethnic, consecutive patients with moderate to very severe glabellar lines were included in this retrospective analysis. The same 3-point glabellar injection technique was utilized, administering a total of 37.5 sU (=15 IU) to the procerus and corrugator supercilii muscles. Glabellar severity was assessed at 20 and 90 days after the initial treatment. Results: Across the entire study sample, a highly statistically significant improvement was observed at all investigated follow-up time points (p < 0.001). When comparing the treatment outcome across the five different glabellar contraction patterns, there was no statistically significant difference detected at either 20 days follow-up (p = 0.373) or 90 days follow-up (p = 0.311). Multivariate analyses confirmed that neither age, BMI, Fitzpatrick skin type, nor glabellar contraction patterns statistically influenced the outcome at 90 days (all p > 0.05). Conclusion: The results of this retrospective analysis revealed that in the sample investigated, no statistically significant differences were detected between patients with different glabellar contraction patterns at any of the conducted follow-up visits when the same glabellar injection technique with the same amount of toxin units was administered.