The human skull is not completely symmetrical because of the differences in age, race, age and itself. Generally speaking, in medicine, if it is within 7%, craniofacial experts think it is acceptable. For example, human beings tens of thousands of years ago had smaller frontal bones than modern people. Westerners have higher brow bones than orientals. Young people's orbital bones are more complete and full than those of the elderly. When you get older, the orbital bone will absorb more up and down, and the cheekbones and mandibles will absorb more. Due to the lack of bone support, the facial skin and fat of the elderly gradually droop. The left and right faces are usually asymmetrical because the size and height of the skeleton are different. Facial appearance does not have to be exactly the same, such as unilateral dimples, big eyes and small eyes, high eyebrows and low eyebrows. Like us orientals, if we often do things, play ball and exercise with our right hand, the skeletal muscle of our right hand will be stronger than that of our left hand. Foreigners, on the other hand, have more congenital lefties, so their left hands are relatively strong. Therefore, people are asymmetric animals. I hope I can help you. Happy new year.