 Chemotherapy and radiotherapy are important therapeutic modalities for head and neck cancer patients. Oral mucositis is a common comorbidity during chemotherapy and radiotherapy. It was reported that 30-60 of patients underwent chemotherapy and over 90 of patients receiving radiotherapy had oral mucositis. Oral mucositis not only reduces the quality of life of cancer patients during therapy but also causes dysphagia and poor nutritional status. Severe oral mucositis may necessitate unplanned gaps between treatment which can undermine the chance of local control. 