If the tooth is in a good position and there is no decay, it can be retained. If there is no occlusion of the teeth in the opposite jaw, the tooth can be extracted in this case. If the tooth is decayed or the nerve is leaking, which causes pain to the patient, it can be extracted in time. If the position of the tooth is relatively oblique, it is easy to cause food embedding or may appear the caries of the neighboring teeth, and may repeatedly appear the phenomenon of pus and swelling, then the tooth should be extracted in time. In addition, if the tooth is swollen at the apical part and has no effect, it can be preserved without destroying the bone and extracted, and if the tooth has a residual root, it should be extracted in time.