The eruption of wisdom teeth is usually around 18 years old, when the jawbone development is basically set. As humans evolve, both the jawbone and teeth tend to degenerate, but the rate of degeneration differs between the two, with the jawbone degenerating faster than the teeth, so that the teeth appear larger in relation to the jawbone, resulting in wisdom teeth obstruction. Few wisdom teeth can erupt to their normal position. In severe cases, the opening is restricted, and localized redness, swelling and fever can affect eating. In addition, there is often food embedded between the wisdom tooth and the second permanent molar, which indirectly causes the second permanent molar decay. Orthodontic patients can also affect the effect of orthodontic treatment because of the eruption of wisdom teeth. There are so many disadvantages of wisdom teeth, and its occlusal function is very small. Therefore, it is necessary to extract them.