A toothache associated with cancer is actually very difficult to differentiate from a toothache caused by ordinary pulpitis. However, it may have many very special clinical manifestations, such as not a single tooth presenting with toothache, the patient may feel that a piece of teeth is indistinguishable from one another, the toothache is all very severe, and there is loosening of multiple teeth occurring in the mouth. By taking X-ray, it can be seen that the resorption of the alveolar bone is not normal or the arrangement of bone trabeculae is disturbed. In this case, it is important to be alert to whether the cancer is from other parts of the body and metastasized to the alveolar bone. There are some patients who know they have cancer themselves and can undergo relevant tests, such as PET-CT, to determine if this location is a metastatic cancer. If it is, it is not recommended to take the treatment of extraction for this tooth, because it is likely to lead to non-healing of the extraction socket, and it is better to use conservative treatment to relieve the pain of the tooth.