Applied Anatomy for Botulinum Toxin Injection in Cosmetic Interventions

Purpose of ReviewTo provide the reader with a clear overview of facial anatomy as it relates to injection of botulinum toxin.Recent FindingsThe review suggests the presentation of multiple combinations of facial musculature, with the forehead, glabellar, and nasal base areas as particular areas of variation. Differences in musculature result in different wrinkling patterns; with age, these changes first become apparent in the upper face, particularly in the forehead and glabellar area.SummaryBotulinum toxin is well suited to achieve the optimal outcome: it is popular, safe, and non-invasive and presents with few adverse effects. Though limited, when adverse effects do arise these are primarily related to poor injection technique, often fuelled by poor anatomical knowledge. For clinicians to achieve the best outcomes with botulinum toxin use, an understanding of the facial muscles' anatomy, actions, and interactions is key. This paper discusses the broad and intricate detail regarding the key target muscles of botulinum toxin, based on both literature review and cadaveric dissection carried out by the authors.