Why do people leak gums in different ways when they laugh?

There are many kinds of smiles, including smiles and laughter. Among them, smiles are divided into postural smiles and spontaneous smiles. A posturing smile refers to a deliberate smile in order to give others a cordial feeling; Spontaneous smile refers to an involuntary smile when you are happy. Then let's talk about how to laugh at your gums. It is normal to show your gums when you laugh heartily, giving people a feeling of youthful vitality. Because with the increase of age, the elasticity of facial muscles will sag under the influence of gravity. After sagging, the gums cannot be exposed, the upper teeth are exposed less, and even only the lower teeth are exposed, which means aging. Under normal circumstances, you should not show your gums or only show a small amount of them when you smile. On this basis, let's talk about why some people show a lot of gums and some people don't. How much a smile exposes the gums is related to hard tissue and soft tissue. For hard tissue, it is the vertical development of maxilla and the alveolar bone length of maxillary anterior teeth. For soft tissue, it is the length of the upper lip (also called the length of the human body). There is a genetic tendency in the development of jaws. Most children whose parents' jaw teeth are irregular are also irregular, and most of their parents smile, because the overgrowth of the front of the maxilla has a genetic tendency. However, this kind of gingival smile with overdevelopment of mandible must be solved by surgery, and how long the maxilla should be cut off and then pushed up. The alveolar bone of the upper teeth and incisors also overgrown. Alveolar bone grows with teeth. After the tooth is pulled out, the alveolar bone is gone, but the jaw is still there. Therefore, this kind of alveolar bone overgrowth can be solved by orthodontics to depress the upper teeth and press the long alveolar bone back. But which one is specific, you need to go to the hospital for examination to determine.