Xerostomia By Bernard J Hennessy, DDS, Texas A&M University, College of Dentistry Reviewed / Revised Feb 2022 | Modified Sep 2022 View Patient Education Pathophysiology Etiology Evaluation Treatment Geriatrics Essentials Key Points Topic Resources Major Salivary Glands and... Some Causes of Xerostomia Xerostomia is dry mouth caused by reduced or absent flow of saliva.