The face is the focus of human interactions, and facial appearance profoundly affects self-esteem. Facial appearance is not only a compilation of the dimensions of the primary morphologic features but is also a direct result of the emotional expressions exhibited on the face. Facial expressions are central in the communication of emotions, as well as in signaling characteristics such as age. The repeated expression of emotions produces hyperfunctional facial lines, and the presence of these lines when the face is at repose may give an erroneous impression of emotions or personality characteristics. These lines are also perceived as a sign of aging. Treatment of hyperfunctional facial lines is beneficial for patients who believe that their faces are not communicating their emotions properly, who want to delay the outward appearance of aging, or who simply want to look their best.