Oral mucositis can be a significant problem for cancer patients. It is typically associated with pain and increased risk of infection and can lead to impaired nutritional status and inadequate hydration.it can be seen in the patient population receiving high-dose head and neck radiation therapy (85%-100%). Topical dexpanthenol acts like a moisturizer, improving stratum corneum hydration, reducing transepidermal water loss and maintaining skin softness and elasticity. The stimulation of epithelization, granulation and mitigation of itching were the most prominent effects of formulations containing dexpanthenol. The investigators suppose that dexpanthenol mouth wash may improve oral mucositis.

Patients will be given a bottle of 5% Dexpanthenol mouthwash and they are asked to rinse 10 ml of it three times a day. At the onset of mucositis and then for 4 subsequent weeks they will be examined to evaluate the condition of their oral mucosa.By the advent of mucositis stage 4 ,at any time during the 4 weeks of study,the patient would be out.if any patient shows allergic reaction to dexpanthenol,he/she would be out of study too.

Inclusion Criteria:

1. without any systemic disease
2. estimated survival of at least 6 months
3. without any mental disorders
4. grade 1 to 3 WHO mucositis

Exclusion Criteria:

1. development of grade 4 WHO mucositis
2. Brachytherapy
3. allergy to the drug
4. dissatisfaction of the patient