Electrophysiologic Frontalis Muscle Response Following Neuromodulator Injections

Abstract

Neuromodulator treatments limit the contractility of the frontalis muscle, resulting in reduced dynamic and static horizontal forehead line formation of the overlying skin. This interventional study investigated the electrophysiologic response (via signal-to-noise [SNR] ratio) and the overlying skin displacement of the frontalis muscle following neuromodulator injections in a total of 11 healthy neuromodulator-naïve volunteers. Relating SNR to the respective skin movement revealed that the higher the SNR, the more vertical the skin displacement is; this remained statistically relevant after gender stratification. These results are novel and will help the aesthetic community to understand neuromodulator effects on the frontalis muscle.

Keywords: Facial anatomy; Facial muscles; Motor-unit action potential; Neuromodulators; Surface electromyography.