An approach to the patient with a dry mouth

X erostomia, or the subjective feeling of a dry mouth, is a common complaint. It is often a consequence of salivary hypofunction (hyposalivation), in which there is objective evidence of reduced salivary output or qualitative changes in saliva. Typically, patients complain of oral dryness only when salivary secretion is reduced by more than half.1 As saliva has a crucial role in taste perception, mastication, swallowing, cleansing of the mouth, killing of microbes and speech, abnormalities in saliva production can significantly affect quality of life. Xerostomia also occurs in patients with no measurable decrease in saliva production. Causes of this ‘subjective’ xerostomia include burning mouth syndrome (better termed neuropathic-induced orofacial dysaesthesia) and psychological and psychiatric disorders, such as anxiety and depression.