Xerostomia is defined as dry mouth resulting from reduced or absent saliva flow. Xerostomia is not a disease, but it may be a symptom of various medical conditions, a side effect of a radiation to the head and neck, or a side effect of a wide variety of medications. It may or may not be associated with decreased salivary gland function. Xerostomia is a common complaint found often among older adults, affecting approximately 20 percent of the elderly. However, xerotomia does not appear to be related to age itself as much as to the potential for elderly to be taking medications that cause xerostomia as a side effect.
Normal salivary function is mediated by the muscarinic M3 receptor. Stimulation of this receptor results in increased watery flow of salivary secretions. When the oral mucosal surface is stimulated, afferent nerve signals travel to the salivatory nuclei in the medulla. The medullary signal may also be affected by cortical inputs resulting from stimuli such as taste, smell, anxiety or depression. Efferent nerve signals, mediated by acetylcholine, also stimulate salivary glandular epithelial cells and increase salivary secretions.

Fonte: The Oral Cancer Foundation
Articolo consigliato dalla socia Maria Antonietta Galluscio.