The Wonders of Spit

by Cathleen Terhune Alty, RDH

Oh, the wonders of spit! It looks adorable bubbling out of a baby's mouth, nasty spattered on the sidewalk, insulting when hurled at another person, and worthy of an Olympic medal when "pit-tooeyed" a great distance. Foamy, stretchy, ropey or thin, saliva changes in texture and quantity within seconds. Nearly as individual as fingerprints, a person's saliva can be analyzed for DNA content, various cancers, and drug usage. So much more than mere water, this alkaline fluid continually bathes oral mucosa, lubricating and breaking down food for digestion. Saliva prevents tooth decay by washing away food debris, limiting oral bacterial growth, and remineralizing teeth because it is packed with proteins and other helpful substances.

Saliva prevents the teeming hoards of bacteria from taking over tongue-town. And, if all of this information doesn't make your mouth water, recent research has shown that a multi-function protein in saliva called SLPI ("slippy") has anti-inflammatory, anti-viral, anti-fungal and anti-bacterial properties, which may explain why the family dog insists on licking his wounds.

The underdog of fluids

Spit is indeed the underdog of body fluids. Irwin Mandel, a professor emeritus at Columbia University and saliva researcher, is quoted as saying, "Saliva doesn't have the drama of blood, it doesn't have the integrity of sweat, and it doesn't have the emotional appeal of tears." But like so many other things in life, you don't know how important spit is until you don't have any.

As dental hygiene professionals know, the term for dry mouth syndrome is xerostomia. More than a minor annoyance or discomfort, it is considered a serious medical problem. There may be difficulty with speech or swallowing, as well as mouth pain. With an estimated 25 million individuals suffering from drug xerostomia alone and many more with varying severities of xerostomia from other causes, you probably have a patient or two with dry mouth, some of whom may not even be aware they have it.

A person who suffers from dry mouth may experience rampant decay, gingival inflammation, periodontal disease, halitosis, a burning sensation in the mouth and tongue, or difficulty in chewing, speaking, tasting, wearing dentures, and swallowing. Many patients with dry mouth do not eat a nutritious diet because of reduced eating enjoyment or embarrassment about their condition. Teeth of dry mouth patients are also at high risk for demineralization of enamel because of reduced salivary flow and the habit of sucking on hard candies. Xerostomia symptoms may be temporary or permanent, depending on the damage to salivary glands. Causes of xerostomia include medication, systemic or psychogenic diseases, medical therapy, mouth breathing, or trauma.

More than 400 prescription and over-the counter medications are known to cause xerostomia. The major drug groups that are considered culprits are the antihypertensives and antidepressants. Antihistamines, diuretics, analgesics, and tranquilizers also may contribute to dry mouth. A patient taking these classifications of drugs should be questioned about dry mouth.

Gland output affected

Systemic diseases that contribute to dry mouth include cancer, diabetes, anemia, blockages or infections of the salivary ducts, stroke, Alzheimer's, Sjogren's syndrome, diabetes, endocrine disorders, lupus, HIV/AIDS, Parkinson's disease, cystic fibrosis, Bell's or cerebral palsy. Some diseases directly affect saliva gland output while others are a combination of the disease process and corresponding medication. Because many of these disorders are seen in the elderly population, dry mouth is seen more frequently with seniors.

Medical therapies also can wreck havoc on salivary gland function. Chemotherapy is a major cause of xerostomia because tender salivary gland tissues are very sensitive to radiation. Although the incidence of head and neck cancer overall has been decreasing, tongue cancer has increased 60 percent in the past 30 years. New techniques and medications are being researched that protect glandular tissue and focus the radiation more closely on the tumor. Bone marrow transplants and trauma to head and neck, as well as nerve damage from wounds or surgery also can lead to dry mouth problems. Infections prior to or following surgery may lead to xerostomia.

Mouth breathers usually have dry mouth and their gingival tissue can become inflamed and bleed easily. Persons under stress or anxiety or those who eat a soft diet may have a decrease in salivary flow.

Dry mouth signals

Xerostomia diagnosis is not always clear. Often its onset is gradual and noticeable only as a minor annoyance to daily life. There may be a need to sip water more frequently, which causes the need to urinate more frequently. A person who may carry a water bottle with them or always has a hard candy or mint in their mouth may be suffering from dry mouth. Another clue is the need to keep a glass of water at the side of the bed for in-the-middle-of-the-night sips. A change in the way food tastes or food preferences (less desire for dry foods, like crackers) or change in voice intonation may be a signal of dry mouth, as can dry eyes or skin. A test can be done to measure a person's salivary output to see if he is deficient.

Awareness of xerostomia is more pronounced in people who have undergone radiation therapy or are taking a new medication. With radiation, the xerostomia effect is usually permanent. Special home care instructions for scrupulous oral hygiene are critical to avoid rampant decay. Daily application of fluoride and more frequent check-ups may be indicated.

The good news is that research is underway to improve this parched condition. Researchers who call themselves the "salivation army" march forward to create new artificial saliva or drugs to pump out more moisture. Specialty oral care products, like Biotene by Laclede Corp., are designed to return the mouth to a moister state and are available over-the-counter. Prescription medications to treat symptoms of reduced salivary output also are successful as long as there is still enough of a gland functioning to prod it into secretion. Some patients have found relief through acupuncture. Use of gene therapy to build new, implantable salivary glands may be coming soon.

Practical tips

Besides research, there are some practical tips to share with patients spitting mad about dry mouth. If a medication seems to be the culprit, suggest the patient talk with the physician to see if the medication can be changed. Researchers generally recommend a person with dry mouth syndrome avoid caffeine-containing beverages, alcoholic beverages and mouthwashes with alcohol.

Drinking sips of liquid throughout a meal can help moisten the food, or try dipping hard foods like cookies or crackers into liquid before eating. Chewing sugarless gum and sucking on sugarless candies may help stimulate salivary flow. Suggest caution with sugared hard candies, gum or very acidic fruits or drinks. Use of a humidifier, especially at night, may help reduce morning dryness. There are specialty cookbooks available for those with dry mouth and even wearable water bags so a water source is always available. Of course, more frequent dental visits with specific home care instructions are always a good idea.

Even though dry mouth can be a debilitating problem, hygienists can help patients discover they have the problem as well as recommend practical information and resources for education and patient comfort. Truly, spit is a wonder and should never be taken for granted.

Cathleen Terhune Alty, RDH, is a frequent contributor. She is based in Clarkston, Mich.

• The average person produces approximately 21/2 pints of saliva per day from three main salivary glands: parotid, submaxillary and sublingual. There are other minor salivary glands, such as the buccal glands in the cheeks, which also secrete saliva.

• The mumps (which has nearly been eradicated in the United States since 1967 due to routine vaccination) involves a swelling of the parotid glands in front of the ears.

• The saliva of the parotid gland contains enzymes called amylases, one of which, known as ptyalin, aids in the digestion of carbohydrates.

• The digestion of carbohydrates begins in the mouth.

• There is a hard rock band called "Saliva" and your teenage patients will think you're cool if you have heard of them.

Spit is a wonder even in the animal and bug world.

• Wasps use saliva and wood pulp to make a hive.

• The Oriental Swift (a kind of bird) makes a nest solely out of saliva, and the nest is the main ingredient in birds nest soup.

• In his famous experiments involving conditioned reflexes, Pavlov got a dog to salivate in anticipation of receiving food.

• A bat or mosquito's meal of blood is kept from coagulating by chemicals in their saliva.

• A blood-thinning drug (called Draculin) was developed from vampire bat saliva and is a very strong anticoagulant, used for heart attack and stroke patients.

• Rabies, malaria and Hantavirus is carried in the saliva of an infected animal.

• Flies drool on food to dissolve it, then they suck it up like a straw with a proboscis, a tubular tongue.

• Cows produce 200 times more saliva in a day than do humans.

• Camels are said to spit when angry and are known to spit great distances.

• carries a water bottle into the operatory
• must spit out a hard candy or breath mint before treatment
• has a visible foam line of sticky saliva on her tongue
• has inflamed gingiva in the anterior portions of her mouth, particularly above the maxillary incisors
• forms a thick but small rope of saliva around the prophy cup during polishing
• swallows infrequently during treatment
• has dry, cracked lips and/or fissured tongue
• needs to clear her throat frequently while reclined
• has candidiasis on palate or tongue

Questions to ask patients to discover if they have dry mouth:

• Does your mouth feel dry when eating?
• Are dry foods (crackers, dry toast) difficult for you to eat?
• Do you feel a burning or sticky sensation on your tongue?
• Do you often sip liquids or suck on candies throughout the day?
• Do you wake up to drink liquids through the night?
• Is chewing or swallowing difficult?
• Do you breathe through your mouth?
• Does your saliva feel thick and ropey or non-existent?

• Oral Cancer Information Center
www.oralcancer.org

• Support for People with Head and Neck Cancer
www.spohnc.org

• Lupus Foundation of America
www.lupus.org

• Sjogren's syndrome Information
www.dry.org

• Laclede Inc.
www.laclede.com

• National Institute of Health
www.nih.gov