Xerostomia
Xerostomia, or dry mouth, is a condition experienced by many head and neck cancer patients, in which the salivary glands do not produce enough saliva to keep the mouth moist. Xerostomia is a frequent side effect of head and neck cancer treatments that is mostly caused by the effects of radiation and made worse by combination with chemotherapy.
Saliva is more important than one might think, and has many different functions. Saliva helps improve one’s sense of taste and is crucial in talking, as well as chewing and swallowing. Saliva lubricates the food to help it pass into the esophagus. In addition, enzymes present in saliva help to start the process of digestion.
Saliva also helps to protect the teeth and gums in the mouth and prevent infection. For example, saliva prevents tooth decay by neutralizing acids in the mouth, reducing the growth of bacteria, and washing away food particles that might otherwise sit on the teeth. Saliva also helps to promote healing of the soft tissues in the mouth.
Because saliva is so important, xerostomia—or a lack of saliva—can have many negative consequences. First, a lack of saliva makes the mouth feel dry, making it uncomfortable to eat and swallow. Second, a lack of saliva is bad for an individual’s overall health, as it can harm the teeth and gums, impeding digestion.
Explore highlights from our virtual meeting where patients, healthcare providers, and nonprofit advocates discussed the challenges of Xerostomia. This event, inspired by the FDA’s Patient-focused Drug Development (PFDD) model, captured valuable patient experiences to inform future drug development for better treatment outcomes.
Signs & Symptoms
Often, dentists are able to diagnose xerostomia before the patient has even noticed it. A dentist may pick up on certain signs of xerostomia.
- Insufficient collection of saliva under the tongue.
- Cavities developing near the gumline and/or chewing edges of the teeth.
- A red and parched tongue.
A patient may also notice signs of xerostomia.
- Dry mouth.
- Cracked lips.
- Bad breath.
- Sticky saliva.
- Difficulty swallowing food.
- Changes in taste.
- Burning sensation in the mouth.
- Difficulty talking.
- A thick coating on the tongue.
Causes
Xerostomia may be caused by a variety of factors, including head and neck cancer treatments, several diseases and syndromes, as well as treatments of separate conditions not related to head and neck cancer.
Known Diseases That Cause Xerostomia
- Sjogren’s syndrome (an autoimmune condition that causes dry mouth and dry eyes)
- HIV/AIDS
- Diabetes
- High blood pressure
- Hepatitis C
- Lymphoma
Xerostomia may also result as a side effect of medications, radiation, chemotherapy, surgery, dehydration, smoking, and mouth-breathing. In particular, the radiation often used to treat head and neck cancers is a major cause of xerostomia. External beam radiation is used to destroy cancer cells, yet it also destroys healthy cells in the process. Depending on the location of the cancer, the radiation treatment may also affect and destroy the cells in the salivary glands. The affected salivary glands are therefore permanently damaged, and are unable to produce saliva. Patients suffering from this side effect of radiation usually produce less saliva overall, and the saliva that they do make is often a thicker consistency, with a viscosity that makes it difficult to process.
Diagnosis
Before making the diagnosis of xerostomia, a doctor should perform several assessments. They will ask the patient about their medical history, the duration and severity of their symptoms, any medications they may be taking, and any previous surgeries or treatments.
The doctor will then perform a physical examination, during which they will feel, or palpate, the salivary glands, watching out for signs of tenderness, enlargement, or unusual firmness. The doctor will also look inside the mouth to look for redness and dental decay, and to assess the amount of saliva coming into the mouth.
Comprehensive Testing for Xerostomia
To thoroughly investigate a patient’s dry mouth symptoms, doctors often proceed with comprehensive testing. These specialized tests not only reveal the severity of xerostomia but also identify underlying causes, crucial for effective treatment planning.
- Sialometry
In this test, a patient actively participates in measuring their saliva flow. The test quantifies the saliva produced by the salivary glands over a specific period. Patients may undergo a stimulated test, where they chew on something to boost saliva release, or an unstimulated test, which measures saliva production without any external stimulus. - Sialography
During this radiographic examination, a healthcare professional injects a small amount of contrast material into a salivary duct. This injection allows for detailed imaging of a particular salivary gland, revealing any abnormalities or blockages. - Scintigraphy
This nuclear medicine scan requires the injection of a trace amount of radioactive material into the bloodstream. The test tracks how quickly the salivary glands absorb and then release this material into the mouth, providing insights into gland function and health.
Each of these tests plays a vital role in diagnosing and understanding xerostomia, guiding healthcare professionals toward the most effective treatment approaches for each patient.
Managing Chronic Dry Mouth
The management of xerostomia has 3 goals.
- Increasing saliva flow.
- Replacing lost secretions.
- Maintaining oral health and controlling and preventing dental cavities.
The chosen management strategy will generally depend on the reason, or etiology, behind the condition. For example, if the xerostomia is being caused by a medication, a doctor may change the dose or switch the patient to a different medication.
Self-Care Strategies for Managing Xerostomia
Patients experiencing xerostomia can actively manage their symptoms with several practical strategies. These approaches aim to keep the mouth moist and lubricated, combating the discomfort and negative effects of dry mouth.
Hydration & Dietary Adjustments
- Take frequent sips of water, especially while eating.
- Stay hydrated at all times.
- Avoid carbonated and/or sugary beverages.
- Avoid sugary, acidic, spicy, or dry foods.
- Avoid extremely hot or cold foods or beverages.
Oral Care Products
- Protect dry lips with oil-based balms.
- Chew sugar-free gum with xylitol or suck on sugar-free candy.
- Avoid mouthwash with alcohol.
- Use mouthwash with a carbocylmethyl cellulose saliva substitute.
Lifestyle Modifications
- Breathe through the nose instead of the mouth.
- Use a humidifier while sleeping.
- Avoid all chewing or smoking tobacco, alcohol, and caffeine.
Products That Can Manage Xerostomia
Sugar-free Salivary Stimulants
Gums, mints, and candies can help stimulate any remaining salivary tissue to produce more saliva. In particular, gums or candies with xylitol are useful because xylitol (a natural sweetener) has been shown to prevent the growth of the bacteria that cause tooth decay. There are also long acting and slow release formulas of these products that may be helpful, and can even be used to provide relief overnight. One example is a brand called Xyliments.
Saliva Substitutes
There are different types of over-the-counter moisturizing sprays, liquids, and gels that can help lubricate the tissues inside the oral cavity, or the mouth. These products provide only temporary relief from symptoms. One example is Biotene.
Alcohol-free Mouthwash & Mouth Rinses
Certain mouthwashes can soothe the mouth and may even help strengthen and remineralize the teeth.
Secretagogue Therapy
Secretagogues refer to drugs used to increase salivary flow. These drugs may help patients whose xerostomia has not been reduced with the aforementioned strategies, but they have not been proven to be effective. These drugs include pilocarpine and cevimeline.
Patients suffering from xerostomia should be sure to see their dentist regularly and maintain their oral hygiene. They should always consult with their head and neck team before having any dental work, such as tooth extraction, implants, or root canals.
