Xerostomia is the sensation of having a persistent, unusually dry mouth due to insufficient saliva production. Saliva is important for maintaining proper lubrication, digestion, and oral health; lack of saliva can result in increases in the number of dental cavities, oral infections, and difficulties in swallowing, chewing, and talking. There are a number of treatment options for relieving xerostomia symptoms, including salivary stimulants and saliva replacements.
Due to the central role of saliva in maintaining oral health, it is important to diagnose xerostomia quickly in order to prevent the development of dental cavities, gum disease, and oral infections. Diagnosis of xerostomia is primarily based upon patient examination. A medical provider will conduct an oral exam and ask about any prescription or over-the-counter medications being taken. During the oral exam, the medical practitioner will look for thick mucous-like saliva, red patches on the hard or soft palate, sores or fissures on the tongue and lips, oral yeast infections, or sticking of the tongue depressor to the patient’s tongue or inside of the mouth. A patient’s dentist may also notice a lack of pooling saliva, an increased rate of dental decay, or gum disease.
Patient examination can be combined with an in-office saliva test called sialometry. Sialometry measures the flow rate of saliva after stimulation with citric acid. Stimulated saliva flow rates for healthy individuals range from 1.5−2.0 milliliters per minute. However, in patients with xerostomia, the stimulated rate of saliva flow can be as low as 0.5−0.7 milliliters per minute.
In certain cases, doctors may assess salivary gland function using sialography, an imagining test used to examine glands for blockages or growths. Sialography can be used to determine if any gland function remains, which can be important for guiding treatment strategy.
A number of prescription and at-home treatment options exist for xerostomia, and the best treatment option for an individual patient will depend on the underlying cause. For those patients who develop xerostomia as a result of medications they are taking, a change in medication dose, type, or timing can sometimes alleviate symptoms.
Saliva stimulants are often used to increase saliva production for those patients who still have semi-functional salivary glands, such as temporary xerostomia due to chemotherapy treatment or systemic disease. Salivary stimulants can consist of over-the-counter products such as sugarless chewing gum and candies, or they can be prescription medications that target activation of the muscarinic M3 receptors, which are responsible for secretion of saliva.
For those patients who no longer have functional salivary glands, such as those who have undergone radiation treatment for cancer, a saliva substitute may be recommended. Saliva substitutes contain cellulose-based agents that lubricate and cleanse the mouth, but they do not induce natural saliva secretions. They are available by prescription and as over-the-counter formulations in liquid, spray, and tablet form.
Several lifestyle changes can also improve xerostomia symptoms. For example, patients are advised to refrain from smoking and consuming alcohol, which both cause drying and irritation of the mouth. Sipping water frequently throughout the day can provide much needed moisture to the oral cavity. Frequent dental visits, avoiding acidic or sugary foods, and practicing good oral hygiene at home can help patients avoid cavities and gum disease. Breathing through one’s nose (instead of the mouth) and keeping a cold air humidifier in the bedroom during sleep can also lessen symptoms.