DID you know that no person can talk or eat if it were not for saliva? This fluid, commonly called “spit”, which is taken for granted, actually contains 31 different proteins plus 20 other substances, most of which comprise many metallic particles.

Many of the proteins and other constituents of saliva protect the soft and hard tissue of the oral cavity. The salivary mucins (slime) coat and lubricate the surfaces of the oral mucosa (lining). These larger molecules prevent bacterial adherence and colonization, protect the tissues from physical abuse and allow them to resist temperature change. Some of the proteins like lysozyme can degrade the cell walls of the bacteria e.g. histatin, lactoferrin and lactoperoxidase, and inhibit microbial growth. Some proteins such as salivary antibodies may protect the teeth against caries.

When the mouth is inactive, saliva flows at the rate of about one tablespoon every ten minutes. Conscious or unconscious, the flow never stops. While chewing gum, the flow rate of saliva averages one tablespoon every three minutes. The most remarkable finding of all studies is the enormous variability of flow rates for both basal (resting) and stimulating (chewing) secretions. These may have up to a 30-fold range. Thus, it is clear that a wide range of saliva production can allow normal oral functions. People with excessive salivary flow do not usually have bad breath.

A dry mouth is experienced when the salivary flow is reduced by at least 50 percent. The oral symptoms of xerostomia (dry mouth due to glands not functioning properly) are: these persons are often thirsty, have difficulty with swallowing, speaking and eating dry foods, need to sip water while eating frequently, have difficulty wearing dentures and often do things to keep the mouth moist. Bad breath is also a side effect.

Other signs and symptoms of the disease include burning or tingling sensations of the tongue, abnormal taste perceptions and fissures (cracks), and sores at the corners of the lips. General symptoms may also involve a dry throat, blurred vision with burning, and itching or sandy feeling in the eyes; a dryness, itching, and burning in the vagina, in addition to a recurrent history of vaginitis. Also seen are dry skin and nose, apart from frequent constipation. Many of these symptoms may also be present in patients without xerostomia, but they are much more common in those with it.

Various other factors cause xerostomia, in addition to more than 400 drugs that can result in a decreased secretion of saliva. Without a doubt, the worst agent capable of causing the syndrome is radiation used in the treatment of oral and thyroid cancer. As far as possible, the glands should be shielded from the full dose of radiation.

Included in the diseases that may cause salivary gland hypo-function are rheumatoid conditions, AIDS, and certain common diseases such as diabetes and high blood pressure. Decreased chewing because of constant liquid diets and in patients whose jaws are wired when broken can induce gland atrophy (shrinkage), leading to dry mouth.

The ability of psychic states to depress the flow of saliva is well known. Depressive effects of anxiety and fear can result in lasting episodes of dry mouth. When no organic change can be found in a patient’s troublesome oral dryness, he should be advised to consult a psychologist or a psychiatrist to explore possible psychogenic factors. Treatment using antidepressant drugs tends to aggravate the degree of oral dryness.
Relief can also be had with sugar-free gum and the controlled use of bromhexine sulparam and pilocarpine HCL.