This wide-ranging guide to dry mouth, or xerostomia, is intended to meet the needs of dentists by providing information on all clinically relevant aspects. After introductory discussion of salivary secretion and function, the potential causes of dry mouth, including diseases affecting saliva production, drugs and irradiation, are examined. Symptoms and signs such as altered taste, bacterial changes and infection are discussed, and impacts on quality of life, described. Diagnostic issues are fully explored, covering the use of clinical scoring scales, difficulties in assessment, detection of early signs and the role of salivary biomarkers. The full range of treatment options and preventive measures is then described, including the use of intensity-modulated radiotherapy to spare salivary function, the value of artificial salivas and the beneficial effects of regular chewing. The book closes by considering future treatment avenues and the potential for salivary gland regeneration.