Xerostomia (also termed dry mouth as a symptom or dry mouth syndrome as a syndrome) is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow (hyposalivation), or have no identifiable cause. A mouth ulcer (also termed an oral ulcer, or a mucosal ulcer) is an ulcer that occurs on the mucous membrane of the oral cavity. Mouth ulcers are very common, occurring in association with many diseases and by many different mechanisms, but usually there is no serious underlying cause. The two most common causes of oral ulceration are local trauma (e.g. rubbing from a sharp edge on a broken filling) and aphthous stomatitis ("canker sores"), a condition characterized by recurrent formation of oral ulcers for largely unknown reasons. Mouth ulcers often cause pain and discomfort, and may alter the person's choice of food while healing occurs (e.g. avoiding acidic or spicy foods and beverages). They may form individually or multiple ulcers may appear at the same time (a "crop" of ulcers).
Symptoms include Dental caries, Acid erosion, Oral candidiasis, Ascending (suppurative) sialadenitis, Dysgeusia, Intraoral halitosis, Oral dysesthesia, Saliva that appears thick or ropey, Mucosa that appears dry, Dysphagia, Difficulty wearing dentures, Mouth soreness and oral mucositis, Lipstick or food may stick to the teeth, Dry, sore, and cracked lips and angles of mouth, Thirst.