Q What is the difference between xerostomia and salivary hypofunction?
A. Xerostomia is a subjective complaint that basically means dry mouth. Salivary gland hypofunction is when there is objective evidence of a reduction in the amount of salivary output. Patients may complain of dry mouth even if their salivary levels are normal. On the other hand, people also have noticeably low levels of saliva with no complaint of dry mouth. So when discussing xerostomia, we must remember that it is subjective. Dry mouth can be a sign of dehydration or a response to irritants in the air like during the recent California wildfires. It may be a symptom of an endocrine disorder. Hypothyroidism, uncontrolled diabetes, Alzheimer’s disease, stroke, uncontrolled hypertension, and kidney disorders can cause xerostomia because they all affect the level of fluid in the body.
Q. Is xerostomia age-related?
A. Yes, if it is viewed as a subjective complaint. Many older people report xerostomia but they are not actually experiencing a reduction in saliva output. As we get older, there is some decrease in the amount of salivary output, however, it has no clinical significance. People who are older are at a higher risk for dry mouth but it is not because of the aging phenomena by itself. It is mostly because they are more susceptible to developing diseases and are exposed to multiple medications. Age, by itself, is not considered a risk factor.
Q. Dry mouth contributes to dental caries. Is there any evidence showing a relationship between xerostomia and periodontal diseases?
A. The connection between xerostomia and periodontitis is not as clear cut as the evidence for dental caries because with periodontal diseases, some studies show that if the quality of saliva is altered, then a person may be more susceptible to developing calculus. It may be that in the absence of saliva’s cleansing action, bacteria don’t get washed away as easily but it is not well established that people who have severe dry mouth are at risk for significant breakdown in the periodontal condition.
WHAT TO LOOK FOR
Q. Are there simple ways that the clinician can diagnose and evaluate salivary hypofunction?
A. Yes, dental hygienists can ask patients if they are experiencing any difficulty swallowing solid or dry food, like crackers, popcorn, or potato chips; if they need to take frequent sips of fluid when swallowing food; or if they need to sip water during the coarse of the night. As far as objective assessment when looking in the mouth, the dental hygienist can see if when using the mirror or the tongue blade, it has a tendency to stick to the buccal mucosa. Under normal conditions, the dental mirror or the tongue blade will not stick to the tissue because it’s glossy, lubricated, and slippery. Crack formation, dryness at the corner of lips, and a patient complaint of lipstick sticking to her teeth are all symptoms of xerostomia.
Also a healthy tongue is smooth and lubricated, and different papilla are noticeable. The tongue in a dry mouth will look fissured, desiccated, and will appear more red than pink. In patients without dry mouth, a pool of saliva is present at the floor of the mouth. In patients with salivary hypofunction, the tissue looks dehydrated. Also when the glands are palpated during a head and neck examination, a clear stream of saliva should result. In a patient with salivary hypofunction, the stream is only one or two drops and then it stops or the patient may pull away in pain.
ADDRESSING THE PROBLEM
Q. What self-care techniques do you recommend for patients with xerostomia?
A. Basically, good oral hygiene is important—brushing, flossing, visiting a dental professional on a regular basis. For patients with dryness, a visit to the dental office every 6 months may not be enough. Those with severe dryness may benefit from visiting the dental hygienist and dentist more often, like every 3 or 4 months. These patients may also want to consider fluoride therapy either at home or in the dental office due to the increased risk of caries. Some dental professionals recommend the use of chlorehexidine if they see a need for an anti-microbial product.
CAUSES OF XEROSTOMIA
Side effects of some medicines. More than 400 medicines can cause the salivary glands to make less saliva. Medicines for high blood pressure and depression often cause dry mouth.
Disease. Some diseases affect the salivary glands. Sjögren’s Syndrome, HIV/AIDS, diabetes, and Parkinson’s disease can all cause dry mouth.
Radiation therapy. The salivary glands can be damaged if they are exposed to radiation during cancer treatment.
Chemotherapy. Drugs used to treat cancer can make saliva thicker, causing the mouth to feel dry.
Nerve damage. Injury to the head or neck can damage the nerves that tell salivary glands to make saliva.
National Institute of Dental and Craniofacial Research. Dry mouth. Available by clicking HERE. Accessed December 17, 2007.
Diet can also be important. Obviously, cleaning the teeth and oral environment after meals to reduce the chance of food debris and bacteria staying in touch with the hard tissue is important. As far as modifying dietary habits, the type of sugar consumed should be looked at because sucrose is the worst, but xylitol has benefits because of its antibacterial properties and anticariogenic activity. But everything in moderation, because if patients consume large quantities of xylitol in lozenges or mints, they may experience adverse effects, such as abdominal cramping or diarrhea.
Overall, taking care of the dentition and soft tissue by debridement, professional care by visiting the dental hygienist and dentist, paying attention to diet, and maintaining balance with hydration are all factors in reducing the risk of xerostomia. For those who spend a lot of time outdoors in warm weather, the need for extra hydration is greater than for those who spend most of their time indoors.
Different climates have an effect. Living where dry winds are common puts people at greater risk for dehydration. For those living where the temperature is hot and they are exposed to severe changes of environment because of the wind, for example, they need to use sunblock on the lips and to consider using different types of moisturizers inside the mouth to keep the tongue from sticking to the roof of the mouth. During the course of the night, if the weather gets really dry, they may want to use a humidifier to keep the air moist. Frequent sips of water will also help.
Most people will be well hydrated if they have 6-8 glasses of water a day. Many patients find saliva substitutes helpful and they are well-liked because of their consistency and flavor.
Lubrication, hydration, and stimulation are all conservative strategies to bring xerostomia under control. But if the condition is systemic, patients may want to visit their physician to inquire about changing medications if this is causing dryness. Treatment is dependent on how severe the condition is, the contributing factors, age, existing medical conditions, access to care, and dietary habits.
Treatment is important because for those with a severe reduction in the amount of saliva, xerostomia affects their quality of life. They may become antisocial, cease to enjoy food, and they may become depressed. Sometimes there is a need for psychiatric intervention because, unfortunately, some of these mental health conditions, like depression and anxiety, by themselves reduce the amount of saliva output. Medications prescribed to treat many mental health problems also cause reduced salivary output. Unlike a patient who presents with dental caries in a tooth and the practitioner can just clean the tooth, place a restorative material, and close the loop, when it comes to complaint of dry mouth, a multidisciplinary approach is necessary and may include the dental professional, the physician, the social worker, and the nutritionist to work together to improve the patient’s quality of life.
Q. What should people experiencing xerostomia avoid?
A. I usually advise patients with xerostomia to avoid basically any cariogenic products, whether it is gum, mint, or food. If they are going to have dessert, I encourage them to rinse their mouth immediately after. I recommend water over cariogenic beverages like soda. I also advise against diet soda because not only are we concerned about the level of sugar but also the acidity. This also relates to citrus juices. I advise people to drink a glass of lemonade or orange juice quickly instead of sipping it to minimize damage. Teeth that are already dehydrated are at greater risk due to acid exposure.
WHAT THE FUTURE HOLDS
Q. Do you see any future breakthrough in xerostomia management?
A. The National Institutes of Health and the National Institute of Dental and Craniofacial Research are both conducting research on the topic. Bruce Baum, DMD, PhD, is a pioneer in the area of using gene therapy to help patients who basically have permanent damage to the salivary gland. He is working on restoring function to damaged salivary glands. I’m confident that in the future there will be more modalities available to help people restore lost salivary function.
From Dimensions of Dental Hygiene. January 2008;6(1): 33-34.