As clinicians, we try to base our practice on scientific evidence, not unfounded dogma. Yet many "rules" in medicine arise from unsupported misinformation passed from teachers to pupils, from peers to peers, and from pharmaceutical companies to practitioners. It is not until someone raises a question that a practice is examined in a critical light. This phenomenon is often true in the fast-growing field of cosmetic and surgical dermatology, where exciting innovations flourish. As new information is distributed readily, and perhaps too hastily, an assumption becomes practice becomes dogma before any vigorous investigation.

It has been long taught that after injection of botulinum toxin, patients should exercise the affected muscles for up to 4 hours to enhance cellular uptake. Every day across the country, countless patients are instructed to raise their brows, to frown, to squint repeatedly for 4 hours as they drive down a busy freeway, as they return to their offices full of puzzled coworkers, and as they sit down to dinner with their children, making odd and distorted facial expressions.