When making a "smile" expression, facial muscles touch each other, resulting in a depression called "dimple".

Dimples are hereditary. This natural dimple may be caused by muscle defects in the cheeks. Sometimes defects are not necessarily bad things, but they often achieve the value of beauty. Not everyone has dimples, but people who have dimples also have different shapes and heights. Under subdivision, dimples are located about 2-2.7 cm above the corners of the mouth, and there are three kinds of dimples: round, oval and fissure. Generally, dimples are the most obvious when you laugh.