Why is the dentition irregular?

Genetic factors are the main cause of malocclusion, and malocclusion is your life. However, some people still can't afford dentition. In fact, they are all "natural beauty", just caused by some acquired environmental factors. Obstacles in the replacement of deciduous teeth and dentition Many people think that deciduous teeth should be replaced, and there is no need to treat them if they are broken. But the health of primary teeth has a great influence on permanent teeth. Many children pull out deciduous teeth in advance due to dental caries or trauma, which leads to the displacement of adjacent teeth and occupies the position where permanent teeth erupt, leading to ectopic eruption of permanent teeth. There are also retention of deciduous teeth, premature loss of permanent teeth and so on. Bad habits Some children like to put their fingers in their mouths. Long-term actions like this will affect the habits of the muscles around the mouth, leading to irregular arrangement of teeth under the action of lateral force for a long time. Biting your lips, chewing on one side, sleeping with your chin supported by your hands or sleeping with a pillow fist are all common. Malnutrition, thyroid dysfunction and respiratory diseases will all affect the development of maxilla and mandible, resulting in uneven tooth arrangement. Malocclusion, also known as crowding, is the most common among patients with malocclusion, and 60-70% of patients with malocclusion can see crowding. The reason of crowded dentition is that the number of teeth and bones is irregular, the number of teeth (the total width of teeth) is relatively large, and the number of bones (the total length of alveolar arch) is relatively small, and the length of dental arch is not enough to accommodate all teeth on the dental arch. Generally speaking, the human mandible is getting narrower and narrower in the process of evolution, but the number of teeth has always been 32. When the narrowed mandible "can't hold" so many teeth, the dentition is crowded, that is, the dentition is uneven.