Healthy teeth generally meet the following four criteria:

          First, there are no dental caries, periodontitis and other oral diseases;

          Second, the appearance and color of teeth are normal;

          Third, the teeth are arranged in order;

          Fourth, the occlusal relationship between upper and lower teeth is normal;

          Meeting these four conditions can be considered as healthy and beautiful teeth. Here we need to emphasize the occlusal relationship between the upper and lower teeth, that is, the apical fossa mosaic relationship between the upper and lower teeth, because it is often ignored by patients. In fact, the chimeric relationship between teeth has the most direct impact on the movement of the jaw during chewing, and then affects the normal growth and development of the jaw.