What is xerostomia?
Xerostomia, more commonly known as dry mouth, indicates your perception of a reduction in saliva and therefore the sensation of having a poorly lubricated and hydrated oral cavity, precisely called oral dryness. Essentially, it means that you have trouble producing enough saliva to properly lubricate your mouth for eating and digestion of food, talking, and other oral functions.
What is saliva?
Saliva is an extremely important biological fluid, made up of 99% water molecules. Its job is to lubricate and emulsify food and it also helps us swallow and speak. In saliva it is possible to find numerous traces and residues of substances that indicate the physiological state of the organism and the presence of any pathological states. In this regard, in fact, scientific research is evaluating and verifying the use of this fluid to perform screening tests for important pathologies such as hepatitis and HIV and is mapping certain RNA sequences to identify genetic diseases.
Consisting of a serous part and a mucosa, saliva is secreted by three salivary glands: the parotid, the submandibular and the sublingual. The mouth also has over 600-1000 minor salivary glands distributed on the palate, on the edges of the tongue and on the lips.
Saliva has very important functions for the oral mucosa, partly preventing bacterial proliferation, but also for digestion; in fact, it contains digestive enzymes such as ptyalin, lysozyme, amylase, proline and lactoferrin, some immunoglobulins which also have a modest antibacterial activity.
The salivary pH is between relatively neutral values, 6 and 7.4 and, furthermore, the presence of potassium and bicarbonate ions produces a buffering effect that balances particularly risky situations such as tooth decay and erosion of dental enamel. The intake of acidic foods and drinks can in fact lower the pH below the 5.5 threshold, leading to the demineralization of the enamel.
What are the causes?
The causes of this disorder are mainly linked to the chronic intake of medicines, in particular if it involves multiple medicines per day and different pharmaceutical classes. Many of the pharmacological treatments most frequently prescribed for common pathologies have in fact a "xerogenic" effect, as they influence the secretory action of the salivary glands, but can also cause xerophthalmia, or dry eyes. Among the "responsible" drugs are:
- anticoagulants
- diuretics
- anxiolytics
- antidepressants
- antihypertensives
- neuroleptics
- antihistamines
- NSAIDs (non-steroidal anti-inflammatory drugs)
- antiretrovirals
- cortisone-based inhalers
- some multivitamin supplements
Xerostomia can also occur due to systemic diseases, in cancer patients treated with radiotherapy in the head and neck area and chemotherapy, or in patients with autoimmune diseases such as Sjögren's syndrome, thyroid dysfunction (hypothyroidism or hyper-thyroidism) or non- diabetes.
Other possible causes may derive from an obstruction of the salivary ducts (stones called sialoliths) or from pathologies affecting the major salivary glands. Even emotional disorders, such as anxiety, stress, depression and eating disorders (anorexia and bulimia) can in some cases cause xerostomia.
If you have been experiencing dry mouth, your dentist is the person you should contact, as they can start to look at the root causes of your troubles and help come up with a plan for fixing it.