Step 1: Note the Patient's Medical History

This should include questions about the patient’s current and past diseases or illnesses, current or past medications, and current or past disease treatments. The reason it is crucial to take note of these is that many diseases and medications can cause dry mouth, a factor linked to increased risk of caries because there is insufficient saliva present in the oral cavity to protect and remineralize teeth during periods of acid attack.2

Diseases or conditions that cause dry mouth include Sjögren’s syndrome (an autoimmune condition that causes immune cells to attack mucous-producing cells in the body and presents itself mainly in women in their 40s and 50s), rheumatoid arthritis, diabetes, HIV/AIDS, Parkinson’s disease, Alzheimer’s disease, cystic fibrosis, asthma, hormonal changes related to pregnancy, perimenopause or menopause, lupus, anorexia nervosa, and pancreatic or liver disturbances. Smoking and drug abuse, particularly of alcohol, opiates, and methadone, also cause dry mouth.2,3

Over 400 medications have a side effect of salivary gland hypofunction, and 90% of the most commonly prescribed medications in the United States have been reported to cause dry mouth. These include antidepressants, tranquilizers, hypnotics, antihistamines, anticholinergics, antihypertensives, diuretics, appetite suppressants, muscle relaxants, and expectorants.2-4

Medical treatments that cause dry mouth include chemotherapy because it decreases salivary flow rate, and head-and-neck radiotherapy, which causes damage to salivary acinar cells.2,3

It should be noted that older patients tend to be more prone to dry mouth since their glands are likely to be more vulnerable to the damaging effects of medications, and since they tend to be more likely on medications, which they are more apt to be taking compared to younger patients.2,3,5

Usually the patient is aware that they have a dry mouth because of the discomfort it causes. Dry mouth can also be detected in a clinical examination: The mouth mirror may tend to stick to mucosal surfaces or the saliva will appear frothy.2