The lips can be open or shut. Your teeth may be exposed. Raise your cheeks. Hold that smile for a few minutes, and see if you start feeling better. Practically all of our facial features are involved in a smile.
Some smiles are broad and spread across the face.
Other smiles are mysterious and enigmatic as the world's most famous smile, the Mona Lisa. A smile is the same in all languages. A smile is inaudible, but conveys a clear message. As a world traveler, you should know about the gamut of emotions that a smile conveys in other cultures. In Indonesia a smile may denote happiness or anger, while the Thais, Chinese, Koreans, and Japanese will smile to express their confusion, embarrassment, or even sadness.