The smile, one of the most beautiful expressions that appear on the face, and in the form of a breakthrough formed on the sides of the mouth, and are usually used to express a form of joy and happiness and pleasure, or feeling of pleasure, or exclamation, but sometimes it is just a feeling of involuntary, . The smile is a natural reaction to a particular stimulant that is joyful, and the motivations that call for the smile vary according to the different environments, cultures and societies. The smile is one of the reasons for logical and mental thinking. The smile is also of a religious dimension, especially in the Islamic religion. Religion calls for the need for people to smile in each other's faces. The Prophet Muhammad (PBUH) says: "You will be treated in the face of your brother as charity." This is clear evidence of the greatness of the smile, It affects the subconscious of man and makes him more powerful. It is worth mentioning that scientists say that man is the only creature who smiles.
