The Face of Emotion: Botulinum Toxin, Emotional Anatomy, and Mood Modulation.

[BACKGROUND] Facial expressions profoundly influence emotional communication and well-being. The facial feedback hypothesis suggests that facial muscle activity can reinforce or modulate emotional experiences. Botulinum toxin type A (BoNT-A), known for its aesthetic applications, is emerging as a modulator of mood through its effects on facial musculature and feedback mechanisms. Its ability to influence mood extends beyond aesthetic improvement, offering potential therapeutic benefits in emotional regulation.

[AIMS] This literature review explores the interplay between facial anatomy, emotional expression, and the potential of BoNT-A to enhance overall mood and well-being, beyond aesthetic improvement.

[METHODS] A literature review was conducted using PubMed with search terms like "botulinum toxin" AND "emotion." Relevant English-language articles from 2000-present were selected based on their examination of BoNT-A's influence on mood and facial feedback. Articles not in English and lacking relevance were excluded. Citation tracking was used to identify additional studies, and insights from the authors' clinical expertise further informed the review.

[RESULTS] A total of 46 articles were included based on their relevance to both BoNT-A and emotional states. BoNT-A-induced muscle relaxation can prevent specific muscle contraction and thereby disrupt feedback loops that reinforce mood, potentially enhancing positive emotions and promoting overall wellbeing. Studies suggest that BoNT-A injected into the glabella region can modulate amygdala activity, reduce symptoms of depression and anxiety, and strengthen overall emotional resilience. By modulating facial expressions, BoNT-A can also enhance social interactions, increase positive emotional contagion, and contribute to a more positive self-perception.

[CONCLUSION] BoNT-A shows promise as a novel approach to mood regulation and enhancement by altering facial feedback mechanisms. Its dual aesthetic and therapeutic benefits highlight its value in both dermatology and mental well-being.