For teeth that are so bad that they cannot be retained, if they are not filled in time, it will gradually cause: ① local bone resorption; ② skewing of neighboring teeth to the gap; ③ elongation of the opposing teeth; ④ long-term eating inconvenience, etc. In order to avoid these problems, it is necessary to consider filling the gap as soon as possible. Generally, there are 2 methods to choose from: 1) restoration, planting a tooth in place or setting a tooth, this method saves time; 2) orthodontics, moving the teeth on both sides of the gap to close the gap, so that the mouth is full of their own teeth. This method takes longer, but it can solve other dental problems such as crowded teeth, convex teeth/mouth, etc.