There are two possibilities for an extra tooth to come out: the first one may be an obstructed wisdom tooth, because people’s food is getting more and more fine nowadays, so the jawbone does not get enough stimulation, which also leads to the wisdom tooth not having enough position to erupt, forming an obstruction. If this is the case, it will lead to wisdom tooth pericoronitis, adjacent tooth decay, pulpitis, tooth loosening, periodontitis, etc. The best treatment is to remove the wisdom tooth as soon as possible to prevent these diseases from occurring in order to eliminate future problems. The second type is the multiple teeth, because during the embryonic development period, there may be an extra tooth capsule, resulting in the residual in the jawbone or erupting in the oral cavity to form multiple teeth later, this situation will cause damage to other teeth and periodontal tissues, leading to the possibility of adjacent tooth caries, pulpitis, periodontitis and so on. The best treatment is to remove the wisdom teeth early and then orthodontic treatment is performed to restore the normal shape of the teeth.