When doing orthodontics, if the doctor says that the gap between teeth is too small, it is necessary to grind the teeth smaller. When doing orthodontics, never grind your teeth, because there is a protective film on the outside of your teeth. When you grind your teeth smaller, you will wear away the protective film. No matter how you protect it in the future, you will easily get dental caries, especially when you are doing orthodontics. It is the front teeth, unlike the back molars. Once the front teeth have decayed teeth, it is difficult to fill them.