All malignant tumors including oral and maxillofacial – head and neck are a kind of genetic disease, which means that the genes in the tumor tissues are defective. Gene therapy is a biomedical high technology that introduces normal genes or genes with therapeutic effect into human tumor cells in certain ways to correct the defects of genes or to play a therapeutic role, so as to achieve the purpose of tumor treatment. Gene therapy is different from conventional treatment methods: conventional disease treatment targets various diseases caused by abnormal genes, while gene therapy targets the root cause of the disease, the abnormal gene itself. P53 gene is an important tumor suppressor gene. Abnormal alterations of p53 gene occur in oral and maxillofacial-head and neck malignancies as well as most human tumors. Therefore, correction of p53 gene abnormalities has an important role and developmental prospect for oral and maxillofacial-head and neck malignancies. In recent years, we have used p53 gene in combination with chemotherapy and/or surgery for the treatment of oral and maxillofacial-head and neck malignancies, which has significantly improved the therapeutic efficacy. A study in more than 30 medical centers in the United States, Canada, Japan and Europe also demonstrated that the efficacy of p53 gene therapy in combination with chemotherapy or radiotherapy for recurrent advanced squamous head and neck cancer without surgical indication was 73%, much higher than other traditional methods. Recombinant Human P53 Adv Injection (trade name: Gendicine) is a P53 gene therapy product for the treatment of malignant tumors, which has been approved by the State Food and Drug Administration and is the first gene therapy drug approved for marketing in the world. It has proven to have clear efficacy against malignant tumors including oral and maxillofacial-head and neck tumors as well as more than 40 other major human solid tumors. The mechanism of P53 gene therapy for tumor treatment is: (1) it specifically causes programmed tumor cell death or puts tumor cells in a severe hibernation state without damaging normal cells; (2) damaged DNA present in tumor cells is an important activator of p53 gene expression, and highly expressed p53 protein can effectively stimulate the body’s specific anti-tumor immune response; (3) p53 (3) p53 tumor suppressor gene can regulate cell S-phase to G1-phase growth and prevent cell carcinogenesis; (4) P53 gene is a key “genomic protector” in cells, which has the function of upregulating the activity of many anti-oncogenes and downregulating many oncogenes, and inhibiting the expression of VEGF and MDR genes. In addition to fever in some patients, no other significant side effects have been found with P53 gene therapy, and no hereditary damage has been reported since the approval of recombinant adenovirus products for clinical trials in 1995. At present, the use of recombinant human p53 adenovirus injection in China is limited to tertiary care hospitals. Treatment options are: combination chemotherapy, combination surgery, combination radiotherapy, combination radiotherapy/chemotherapy, combination thermotherapy, and treatment alone. Depending on the actual situation, the route of administration can be intra-tumoral injection, arterial cannulation, intravenous administration, and thoracic or abdominal perfusion administration.