Facial expressions provide unique insight into an individual’s emotions, and distinct, universal facial expressions have been identified for a multitude of emotions . The anatomy involved with facial expression has been the interest of many investigators over the years. Ekman and Friesen  defined 46 action units that correspond to independent facial movements. Darwin, a student of Charles Bell, sought to anatomically describe the musculature involved in specific facial expressions . Rubin (1974) studied the active, dominant facial musculature and its vector of pull during smiling and described the three main smile types. This anatomical interest in facial expression holds particular importance to the reconstructive surgeon treating facial nerve injuries. Subtle recreation of native anatomy is the ultimate goal, one that is most challenging for dynamic expression.