Background Topics: Introduction -- Salivary Secretion and Function. Causes: Diseases Affecting Salivary Gland Production -- Drug-induced Dryness -- Irradiation Effects. Symptoms: Altered Taste and Diet Associated with Oral Dryness -- Microbiology of Oral Dryness -- How Oral Dryness Impacts on Quality of Life. Diagnosis: Clinical Scoring Scales. Treatment: IMRT as Improved Irradiation Treatment -- Artificial Salivas -- The Beneficial Effects of Regular Chewing -- Future Treatments.