Assessment of Botulinum Toxin Aesthetic Outcomes: Clinical Study vs Real World Practice.
Thirty years ago, few of us could have envisioned today's practice of aesthetic medicine. Led by botulinum toxin type A (BoNTA) innovation in facial injectables has revolutionized our practices. New technologies are poised to further expand aesthetic treatment opportunities in the near future. To fuel continued progress, regulatory bodies must accurately reflect the knowledge and best practices shaped from the research and experience of the past 3 decades. Aesthetic medicine is unique; clinical success is inextricably linked to patient perception and preference. Whereas eradication of acne lesions or squamous cell carcinomas is easily quantified in medical dermatology, optimal outcomes in aesthetic medicine are not as objectively defined. Early usage of aesthetic BoNTA focused on immobilizing the muscles responsible for hyperdynamic lines. This approach dramatically reduced targeted lines yet precipitated a host of poor aesthetic outcomes, most notably the compromise of facial expressiveness. Contemporary aesthetic treatment approaches are more refined, and our dosing recommendations have trended downward to retain a balanced, natural look while diminishing unwanted lines. In August 2014, The US Food and Drug Administration (FDA) issued the draft guidance Upper Facial Lines: Developing Botulinum Toxin Drug Products.1 Although we applaud this document as a good initial step in establishing high standards for aesthetic BoNTA development, aspects of the guidance highlight fundamental misunderstandings of best practices in aesthetic medicine. Specifically, the Efficacy Endpoints section states, in part: "Measurements at maximum contraction should be used to assess the efficacy of botulinum toxin drug products to demonstrate the paralytic effect. "1(p7) "Success should be defined as a two grade improvement from the baseline, on both the IA [investigator's assessment] and the SSA [subject's self assessment] scales concurrently, to ensure clinical significance."1(p8) Taken at face value, these measures may seem to be clear cut methods of evaluating efficacy. In reality, these requirements can foster an approach that increases the risk for overtreatment and poorly reflects contemporary aesthetic practice. The guidance seems to presume that all muscle action associated with facial lines is undesirable. Yet, although muscular contraction creates lines that patients want diminished, it also enables the facial expressions they wish to keep. Facial appearance and emotive ability have important social implications and lay the foundation for social judgments about age and personality characteristics.2 Each facial feature uniquely contributes to the whole, and no single treatment or assessment approach should be applied universally.
JAMA dermatology