The risorius may be a small muscle, but it plays a big role in smile dynamics and it’s one injectors must respect. 🔎 What injectors need to know: Anatomy: lies above the buccinator, with its origin on the surface of the masseter. Function: contributes to smiling by pulling the corners of the mouth laterally. Clinical relevance: it’s often affected indirectly during masseter toxin treatments. → If you relax the risorius by accident, patients can lose smile width or expression, especially after j