These types of complaints are often heard from patients experiencing xerostomia or dry mouth. However, diagnosing xerostomia before a patient complains of dry mouth is possible and important. Dental hygienists are in the key position to make these early diagnoses. Through risk assessment and early detection, hygienists can diagnose and manage xerostomia before their patients incur serious oral and general health problems.
—Dimensions of Dental Hygiene
Please provide a basic definition of xerostomia.
Xerostomia is a subjective complaint of dry mouth, unlike salivary gland hypofunction, which is objective evidence of reduced saliva output. People have different thresholds for pain and in the same way, the amount of wetness in the mouth is different among different people. Some people have reduced salivary output and don’t complain of dry mouth and some complain of dry mouth and don’t have any reduction in the amount of salivary output. That’s why my colleagues at the USC School of Dentistry and I are trying to help dental professionals identify those patients who are at risk for the complications of dry mouth but who may not complain. The movement is more toward risk assessment and disease prevention as opposed to management and treatment because by the time dry mouth is clinically obvious, the damage is already present.
What are some of the causes of xerostomia?
The most common cause of dry mouth is the use of certain medications that carry dry mouth as an adverse effect and those that affect the amount of salivary secretion in the mouth (see Table 1). Some less obvious causes are the daily use of over-the-counter medications such as those used to manage allergies, anxiety, depression, pain, and digestive problems. Most patients don’t know that frequent use of these kinds of medications over long periods of time can cause permanent damage to their teeth and gums when salivary gland hypofunction occurs as an adverse effect.
Many of the medical conditions that affect oral health but did not receive much attention in the past are now getting more visibility. HIV by itself can affect the amount of saliva that an individual has as do some of the antiretroviral medications commonly used by HIV-infected patients. HIV-infected individuals are susceptible to fungal infection because they are immunocompromised and saliva has antifungal properties. Sjögren’s syndrome is an autoimmune disorder where the body produces chemical antibodies against its own structure, mainly the lacrimal gland, which is responsible for producing tears, and salivary glands, which are responsible for producing saliva. Patients may not always complain using the label “dryness.” They may complain of sore mouth, burning mouth, or that food doesn’t taste the same. Clinicians may not immediately realize that these are symptoms of dryness.
Does intermittent xerostomia put patients at risk for permanent damage?
No, if the xerostomia occurs for a short period of time, the changes are reversible. Oral health will go back to normal once the medication is discontinued or the patient no longer has the related condition. However, there are patients who, for example, suffer from multiple allergies and over the course of years continually take a medication that has salivary gland hypofunction as an adverse effect. This may result in permanent damage. These types of patients also frequently adopt unhealthy dietary habits, ie, over-use of lozenges and cough drops or sucking on candies.
With an aging population, is the incidence of xerostomia expected to increase?
Xerostomia is a common complaint among geriatric patients. As men and women continue to live longer in the presence of multiple medical conditions and medications, the risk for salivary gland hypofunction and xerostomia increases. Age by itself is not a significant risk factor. As we get older, there are changes that affect our salivary glands but the amount of reduction in the salivary output caused by aging is not clinically significant. Medications and medical conditions put geriatric patients at risk. Under normal conditions, we really need only about 50% of the healthy cells in the gland to produce saliva. The other 50% of the cells are in reserve. So as we get older and lose some activity, we still have enough cells to go on and experience a healthy life.
Describe the complications our patients may experience and how to best help them.
The complications of salivary gland hypofunction or chronic dry mouth are each different. They fall into three different categories. First, salivary gland hypofunction affects the hard structure-tooth enamel, increasing the patient’s susceptibility for dental caries.
The second category is soft tissue. As mentioned earlier, salivary gland hypofunction increases susceptibility for fungal or yeast infection. People who don’t have enough saliva may be at risk for periodontal diseases because in the absence of salivary cleansing properties, food is retained longer on the teeth, accelerating plaque formation. Finally, people may complain of bad breath, bad taste, or a burning sensation.
When looking at a patient’s mouth, you may see caries, soft tissue changes because of yeast infection, or sensory deficit. An ill-fitting prosthesis can also be a problem. If the prosthesis doesn’t fit properly, the lubricating effect of saliva is lost so patients have constant friction from the prosthesis. The key to effectively treating dry mouth is to prevent it. Asking pertinent questions is helpful as is paying special attention during the process of head and neck evaluation and if you are suspicious to actually objectively measure the amount of saliva present.
What questions should we ask patients in order to ascertain their risk of abnormal salivary function?
If the patient answers yes to any of the four following questions, the patient is at risk. The questions are:
- Does the amount of saliva in your mouth seem too little?
- Do you have any difficulties swallowing?
- Does your mouth feel dry when eating a meal?
- Do you sip liquids to aid in swallowing dry food?
A yes response to the first question is an indication of reduced unstimulated whole saliva. The last three questions are associated with stimulated whole saliva production. Whole basically means that it is a combination of saliva from all of the glands like parotid glands, submandibular glands, sublingual glands, and minor salivary glands. Assessment should incorporate what complaints patients are presenting; how they respond to the questions when clinically evaluated; if dryness is evident involving the tissue; if carious lesions are present; if the color and consistency of the soft tissue are different than normal; and if the tongue looks white, coated, chapped, fissured, or dried. All of these must be taken into consideration in addition to the patient’s medical history. After reviewing these, the clinician decides if the patient should be referred for further diagnostic workup. If there is a need for further diagnostic workup, the saliva can be collected objectively to see how much is present. Imaging is another option that will provide a radiographic evaluation of the major glands. Nutritional counseling may be needed to avoid a diet high in sugar.
Where should we refer patients who need further diagnostic testing?
Until a few years ago, saliva testing was only done for research purposes. Recently, it has received increased attention as a diagnostic tool. Saliva is easy to collect and the procedure is less invasive than collecting blood. In some states, the only available laboratory for saliva testing is in an academic institution. For those who do not have access to saliva collection and testing, there are simple ways to determine if the person is at risk (see Table 2 for indicators of abnormal saliva function).
What is burning mouth syndrome and what is its relationship to xerostomia?
Classified as a chronic pain disorder, burning mouth syndrome is the persistent complaint of burning in the absence of any structural changes. When all the other causes and conditions of known disorders are eliminated, then the diagnosis of burning mouth syndrome is made. It is more common in women than men.
Are there new treatments for xerostomia, both palliative and long-term?
There are some medications like Pilocarpine that became available for oral usage in the late 1980s, early ’90s, to increase the amount of saliva in the mouth. Another medication was introduced 2-3 years ago called Evoxac, which is a pill taken three times a day. Both medications have adverse effects and there are some medical conditions that are contraindicated to their use. Sugar-free chewing gum and lozenges may help increase saliva production. Hydration plays a significant role. Frequent daily application of plain water is important. Different types of lubricants, moisturizing ointments, and saliva substitutes are available in different compositions.
New research is being conducted by Bruce Baum, DMD, PhD, at the National Institute of Dental and Craniofacial Research on using gene therapy for the treatment of dry mouth. In gene therapy, innocuous viruses teach the cell to start secreting saliva. The damaged cells are converted or new cells are formed with the ability to produce saliva.
|Table 1. Common drug classifications that induce xerostomia.|
6) Anti-inflammatory analgesic
9) Muscle relaxant
|Table 2. Diagnostic tips for abnormal saliva function.|
|1) When evaluating a patient, you should be able to easily remove the tongue blade or the mirror from the tissue when the cheek is retracted. If there is a tendency to stick, the tissue isn’t as lubricated as it should be.
2) When the major salivary glands are palpated, clear saliva should appear. If nothing comes out or if the saliva is contaminated with puss or blood, this is a suspicious sign.
3) Before beginning any procedure and before you put the saliva ejector in the mouth, lift the tongue and look at the floor
of the mouth. Under normal conditions, the saliva pool is visible. The saliva will bubble and is moist. If saliva is not present and the gland is milked with no results, this is an indication of abnormal function.
4) In patients with good oral hygiene, the tongue should look moist. If the tongue has deep fissures and is dry, lobulated, and has a white coating, this is an indication that saliva function is abnormal.
From Dimensions of Dental Hygiene. September 2004;2(9):24, 26-27.