Finding comfort with a dry mouth

Causes of xerostomia and treatment

By Diana Lamoreux, RDH, MEd

Patients who present with chronic symptoms associated with xerostomia are some of the most uncomfortable, despondent people seeking treatment in dental practices today. Up to 30% of Americans experience dry mouth at various points in their lives. Xerostomia is a symptom, not a disease entity, and can be temporary, reversible, or permanent.

Once considered an inevitable part of the aging process, xerostomia is now associated with hundreds of medications and numerous nonpharmacologic conditions, including some cancer treatment regimens. Growing numbers of patients experience dry mouth due to longer life spans, and the medications and diseases that often accompany living several decades. The elderly are most affected due to a higher incidence of medication usage and compromised health from disease.

There are many common causes of dry mouth -- antihistamine use for allergies and colds, high fevers with dehydration, anxiety, scary movies, public speaking, dental procedures, heredity, snoring, and mouth breathing, but medications and nonpharmacologic conditions are the most frequent causes of xerostomia. Regardless of age or etiology, when xerostomia is the result of a reduction in salivary flow and lasts for months or years, significant oral complications can develop. Early detection is important before the onset of nutritional deficiencies, infection, and rampant caries.

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Medications, diminished health, and cancer treatment can reduce salivary production and/or alter its composition. Much more than a chronic irritation, dry mouth can contribute to a decline in dental and general overall health. When xerostomia is long term, diligent attention to the signs, symptoms, and causes is critical for professionals and patients. The hardships patients experience with xerostomia are sometimes overlooked or underrated, as the condition is difficult to treat. Therefore, it can pose quite a challenge for practitioners to ameliorate a patient's suffering.

Review of the role of saliva

The average, healthy person produces about a quart of saliva daily. It is produced by three pairs of major salivary glands and hundreds of minor salivary glands. Saliva is composed of 99% water. The remaining 1% contains about 60 substances, including electrolytes, enzymes, and proteins. Saliva is an essential body fluid that protects the oral cavity and preserves oral functions. During xerostomia, the loss of salivary proteins and electrolytes accelerates the caries and infection process by decreasing the buffering action and increasing the number of deleterious microorganisms.

Saliva's role is much more complex than moistening food during chewing and allowing for easier swallowing. Here are the multiple functions of saliva:

The enzyme called amylase breaks downs starches into maltose and dextrin, initiates fat digestion, and begins the digestion process; insufficient levels compromise digestion.
The calcium and phosphate in saliva promote remineralization; diminished salivary flow reduces mineral availability.
The proteins in saliva provide antibacterial peptides, protective statherins (prevent calcium and phosphate precipitation), and lubricating mucins.
Saliva neutralizes organic acids produced in biofilm; inadequate saliva lowers pH.
Saliva distributes and recycles fluoride.
Saliva protects hard and soft tooth structures from drying.
Adequate saliva discourages the growth of acidophilic bacteria.
Before vomiting, the brain signals the salivary glands to increase salivary production. This action decreases oral acidity and protects oral structures from acidic emesis.
Some research scientists believe that saliva may have an immunological purpose in humans.

Signs and symptoms of xerostomia

Compromised salivary production will cause any or all of the following symptoms: viscous, sticky saliva; a dry or burning feeling in the mouth, lips, and throat; cracked lips and commissures; a rough, fissured, biofilm-laden tongue; severe halitosis; and mouth sores. These symptoms can create difficulties such as impaired taste, mastication, swallowing (especially dry foods) without fluids, speaking, and digestion. In addition, a dry mouth may exacerbate dental caries, initiate thrush infections, allow prosthetics to abrade, and lead to a change in dietary preferences and unwanted weight loss. As a result of the multitude of possible side effects, xerostomia can affect an individual's nutritional status, leading to vitamin, mineral, and caloric insufficiencies. (NOTE: Symptoms may occur without a measurable reduction in salivary gland output.)

Types of medications that cause xerostomia -- Some experts believe that more than 700 medications, both OTC and prescription, can cause or exacerbate xerostomia. Most of the medications associated with dry mouth affect the sympathetic nervous system, thickening and limiting the flow and quality of saliva. The types of medications most likely to create the symptoms of xerostomia include antidepressants and antianxiety drugs, antihypertensives, antihistamines and decongestants, some analgesics, antidiarrheal medications, muscle relaxants, and drugs that treat urinary incontinence and Parkinson's disease. The website www.drymouth.info provides a comprehensive, searchable list of medications associated with dry mouth.

Nonpharmacological causes of xerostomia -- The causes of xerostomia not directly associated with medications include the following -- accidental or surgical nerve damage to the oral cavity, tobacco use, facial or neck radiation (permanent, no effective treatment has been identified, patients often develop mucositis), chemotherapy, surgical removal of glands due to a neoplasm, autoimmune diseases (specifically Sjogren's and lupus), sarcoidosis, myasthenic syndrome, burning mouth syndrome (BMS), amyloidosis, HIV, hepatitis C, poorly-controlled diabetes, hyperthyroidism, Parkinson's, 60% of bone marrow transplant recipients, some varieties of cirrhosis, gastritis, pancreatic disease, mental illness, and apoplexy. With conditions such as BMS, Parkinson's disease, mental illness, and stroke, a dry mouth sensation can be a perception by the patient even when the salivary glands are functioning normally.

Treatment options

After clinicians assess patients, attempt to identify the possible cause(s) of xerostomia, and educate patients about their condition, viable treatment options can be offered. Meanwhile, any dental treatment should be noninvasive. Diet counseling, instruction for rigorous biofilm control, daily oral self-examination, regular prophylaxis, adjusting home humidity, avoiding tobacco, caffeine, acidic drinks, and alcohol, and application of chlorhexidine-thymol combination varnish on root surfaces and sealants to pits and fissures are all viable alternatives. Patients can become so uncomfortable they may resort to electrical stimulation of the salivary glands and acupuncture when the suggested treatment modalities prove unsatisfactory. Limited studies have demonstrated that acupuncture does alleviate symptoms in some patients with radiation-induced xerostomia.

Numerous products and endorsements are available that can temporarily substitute for the functions of saliva, counteract damage, and compensate for a less than favorable oral environment.

The therapies listed here are considered palliative but may offer some protection from the condition's more significant complications, such as caries, infection, and nutritional deficiencies, and can help patients cope with the unpleasant symptoms.

Change the medication producing the dry mouth
Sipping water or melting ice in the mouth
Prescription dentifrices such as Prevident and Clinpro 5000
OTC and Internet dentifrices containing higher amounts of xylitol (10% to 36%) to control acidophilic bacteria (Tom's of Maine, Spry by Xlear)
OTC dentifrices containing triclosan or sodium bicarbonate (both have antimicrobial properties)
Refrain from using dentifrices containing the drying agent SLS
OTC fluoride or xylitol mouth rinses (ACT Dry Mouth Mouthwash)
Regular use of xylitol-containing (first listed ingredient) products that mechanically stimulate salivary flow and discourage S. mutans (TheraGum by 3M ESPE and X-Pur mints and gum by Oral Science, Canada)
OTC saliva substitutes that stimulate, moisten, and lubricate oral tissues, palliative products that contain carboxymethylcellulose (CMC), calcium and phosphorus, fluoride and other typical salivary ions (Biotene products by GlaxoSmithKline)
Gels that neutralize oral pH (Dry Mouth Gel, GC America) and lozenges (SalivaSure) with citric acid that chemically stimulate salivary flow (available on the Internet, several manufacturers and distributors)
Adhesive tablets applied to the palate (OraMoist by Quantum Health and XyliMelts by Oral Health) contain xylitol, a lubricant, oral enzymes, buffering compounds, and salivary secretion inducers
Application of vitamin E-containing ointment to dry lips
OTC (Oasis and Salivart Spray) and prescription artificial saliva (Neutra-sal) products that contain buffering and flavoring agents but no digestive enzymes or proteins
Customized night trays with remineralizing agents (several products available)
Prescription sialagogue medications such as pilocarpine (Salagen), cevimeline HCl (Evoxac), anethole trithione (Sialor) and bethanechol (Urecholine). These drugs enhance secretion for a few hours. Patients should increase fluid intake during use. NOTE: The ADA does not currently recommend the use of salivary-stimulating drugs due to a lack of quality evidence-based research on the efficacy of drugs that increase the flow rate of saliva.

Dry mouth, especially when it is chronic, drastically alters the quality of patients' lives. Xerostomia is such an unpleasant condition and sometimes the chief complaint in dental offices. Early diagnosis along with symptom management can be a major contribution to the general and oral health of patients. Patients commonly seek relief and solutions from dental practitioners prior to a visit to their primary care doctors. Therefore, dental hygienists are often the first to recognize xerostomia or initiate a discussion about the ramifications of xerostomia.

If xerostomia continues, the focus becomes prevention, maintenance, comfort, and emergency treatment. Since it can be quite a challenge for patients to maintain good oral health, frequent recare appointments with a commitment to conscientious home care is critical. Suggestions that clinicians can offer patients are often just temporarily soothing but may offer some protection from the condition's more significant complications.

Diagnosing dry mouth

Early detection is important before the onset of nutritional deficiencies, rampant caries, and infection. Even when not reported, xerostomia is often first noticed when a clinician's gloves stick to mucosa. Otherwise, dentists and hygienists can be instrumental in detecting early signs of xerostomia by observing the amount of saliva that pools under and around the tongue during dental procedures -- little or no pooling may indicate a patient's salivary flow is compromised (Sjogren's).

Dentists and physicians can diagnose dry mouth. Their diagnostic priority is twofold¬ -- to determine if dry mouth is caused by a change in salivary function, and the gravity of salivary impairment. The following are some assessment options to consider when xerostomia is suspected:

Along with a complete medical history, obtain specifics about the symptoms duration, frequency, and severity. Document any dryness reported by the patient at other sites (ear, nose, throat, skin, and vagina).
Palpate the major salivary glands for tenderness, firmness, or enlargement.
Analyze the amount and quality of saliva coming from the major ducts.
Look for the presence of inflammation and/or decay.
Salivary flow rate can be evaluated in a hospital setting via a noninvasive, painless test called scintigraphy, in which the amount of saliva during a specific period of time is measured. This assay monitors the rate at which a small amount of injected radioactive material is taken up from the blood (by the salivary glands) and secreted into the mouth.
Pathologists can examine biopsied lower lip minor salivary glands and assess them for changes characteristic of the salivary component of Sjogren's syndrome. Sjogren's is an autoimmune condition that creates a dry mouth and eyes, wherein the white blood cells attack moisture-producing glands in the body.

DIANA J. LAMOREUX, RDH, BS, MEd, graduated from Ohio State University in 1972, practiced dental hygiene for over 30 years, was a part-time clinical instructor in the Cleveland area since 1981 and recently retired in December 2011.

References

Guggenheimer J. "Xerostomia: Etiology, recognition and treatment," J Amer Dental Assoc/JADA 2003; 134:61-69.

Sjogren's Syndrome Foundation: Dry Mouth: A Hallmark Symptom of Sjogren's Syndrome. Available at: http://www.sjogrens.org/home/about-sjogrens-syndrome/symptoms/dry mouth. Accessed October 7, 2013.

Specialty Pharmacy Times. Drug-Induced Dry Mouth. Available at: http://pharmacytimes.com/publications/issue/2011/November Accessed October 7, 2013.

Wick J. "Xerostomia: Causes and Treatment," American Society of Consultant Pharmacists/ASCP 2009; 22: 985-992.

National Institutes of Health: Dry Mouth. Available at: http://www.nidcr.nih.gov/oral Accessed October 11, 2013.

Mayo Clinic: Dry mouth: Causes. Available at: http://mayoclinic.com/health/dry-mouth/HA00034/DSECTION=causes. Accessed October 7, 2013.

American Dental Association Council on Scientific Affairs: "Non-fluoride caries preventive agents -- A systematic review and evidence-based recommendations." J Amer Dental Assoc/JADA 2011; 142(9):78-82.

Wilkins EM. Clinical Practice of the Dental Hygienist, 10th Edition, page 391, Philadelphia: Wolters-Kluwer, 2009.

Wong RKW, Jones GW, Sagar SM. "A phase I-II study in the use of acupuncture-like subcutaneous nerve stimulation in the treatment of radiation-induced xerostomia in head-and-neck cancer patients treated with radical radiotherapy." International Journal of Radiology/IJR m2003; 57: 472-80.

Klasser M, Pinto A, Czyscon J. "Defining and diagnosing burning mouth syndrome." J Amer Dental Assoc/JADA 2013; 144:1135-1141.