The increased incidence of cancer patients is unavoidable; the head and neck cancer represents a major oncological problems, due to their high mortality and the consequences of their treatment. Radiotherapy is an important treatment option for many lesions in this anatomical region, used as a single resource or in combination with other therapeutic modalities, however, the effects of radiation do not only affect malignant cells, but it is also absorbed by healthy oral tissues, particularly by those with greater cellular renewal capacity. Mouth lesions occur during and after radiation, which decrease the quality of life of these patients and sometimes can interfere with the continuity of radiotherapy, putting your life at risk. Therefore, it is important to apply preventive dental protocols in an individualized way before starting radiotherapy, to maintain and improve their quality of life during this oncological treatment that affects the oral cavity.