Xerostomia or Dry Mouth – Introduction, Causes, and Pathophysiology.

Introduction

Dry mouth, or xerostomia, refers to a condition in which the salivary glands in your mouth don’t make enough saliva to keep your mouth wet. It is often due to the side effect of certain medications or aging issues or as a result of radiation therapy for cancer. Less often, dry mouth may be caused by a condition that directly affects the salivary glands.

Saliva helps prevent tooth decay by neutralizing acids produced by bacteria, limiting bacterial growth and washing away food particles. Saliva also enhances your ability to taste and makes it easier to chew and swallow. In addition, enzymes in saliva aid in digestion. Decreased saliva and dry mouth can range from being merely a nuisance to something that has a major impact on your general health and the health of your teeth and gums, as well as your appetite and enjoyment of food.

Pathophysiology

Stimulation of the oral mucosa signals the salivatory nuclei in the medulla, triggering an efferent response. The efferent nerve impulses release acetylcholine at salivary gland nerve terminals, activating muscarinic receptors (M3), which increase saliva production and flow. Medullary signals responsible for salivation may also be modulated by cortical inputs from other stimuli (eg, taste, smell, anxiety).

Causes that develops Xerostomia

Possible causes include:

Medications: Many prescription and OTC medications cause dry mouth, including antihistamines, decongestants, hypertensive medications (for high blood pressure), antidiarrheals, muscle relaxants, urinary continence drugs, some Parkinson’s disease medications, as well as a number of antidepressants.

Age: Even though the dry mouth is not a natural part of aging, older adults tend to take more medications than the rest of the population. Many of the medications taken by seniors cause dry mouth.

Cancer treatment: Radiotherapy (radiation therapy) to the head and neck can damage the salivary glands, resulting in less saliva being produced. Chemotherapy can alter the nature of the saliva, as well as how much of it the body produces.

Injury or surgery: This can result in nerve damage to the head and neck area can result in dry mouth.

Tobacco: Either chewing or smoking tobacco increases the risk of dry mouth symptoms.

Dehydration: This is caused by lack of sufficient fluids.

Exercising or playing in the heat: The salivary glands may become dry as bodily fluids are concentrated elsewhere in the body. Dry mouth symptoms are more likely if the exercise or playing continues for a long time.

Some health conditions, illnesses, and habits can cause dry mouth, such as:

• Anxiety disorders
• Depression
• HIV/AIDS
• Parkinson’s disease
• Poorly controlled diabetes
• Sjögren’s syndrome
• Sleeping with the mouth open
• Snoring
• Stroke and Alzheimer’s disease, although these are more likely to cause a perception of dry mouth even when the salivary glands are functioning appropriately

Risk Factors for Xerostomia

Frequently a consequence of:

• Stress
• Radiation therapy of the head and neck
• Glandular fibrosis or destruction
• Mouth breathing
• C Pap use
• Circadian rhythms
• Gender

A side effect of certain diseases and infections include Sjögren’s syndrome, Sarcoidosis, HIV/AIDS, Alzheimer’s disease, Diabetes, Anemia, Cystic fibrosis, Crohn’s disease, Systemic Lupus, Erythematosus, Rheumatoid arthritis, Hypertension, Parkinson’s disease, Stroke, Mumps, Scleroderma, and Hepatitis.

A side effect of using recreational drugs include Methamphetamines, Cocaine, and Ecstasy

Symptoms and associated complications

A lack of moisture in the oral cavity can cause several different clinical signs and symptoms that hamper the quality of life of patients that suffer from xerostomia. If you’re not producing enough saliva, you may notice these signs and symptoms all or most of the time:

• Dryness or a feeling of stickiness in your mouth
• Saliva that seems thick and stringy
• Bad breath
• Difficulty chewing, speaking and swallowing
• Dry or a sore throat and hoarseness
• Dry or grooved tongue
• A changed sense of taste
• Problems wearing dentures
• In addition, dry mouth may result in lipstick sticking to the teeth.

 

The most common complications are related to:

• Chewing
• Swallowing
• Phonation
• An alteration of taste perception (dysgeusia),
• Pasty morning mouth
• Burning mouth sensation

A decrease in saliva makes the soft tissues more susceptible to dryness, redness, irritation and cracking, facilitating the attack of opportunistic microorganisms. This, in turn, promotes inflammation of the mucosa (mucositis), inflammation of the gums (gingivitis), the presence of painful ulcerations and local fungal infections such as candidiasis, lip fissures, halitosis. It is often related to pharyngitis, laryngitis, dyspepsia or constipation.

The main effects of reduced salivary flow on dental tissues include an increase in carious lesions and tooth sensitivity.

In patients with xerostomia who wear dental prostheses, rubbing causes erosion on oral mucosa.

Diagnosis and Test for Xerostomia

History – Specifics of the complaint of dry mouth are obtained: duration, frequency, and severity. The history of dryness at other sites (eyes, nose, throat, skin, and vagina) is documented. A complete medical and prescription drug history is obtained.

Examination – Major salivary glands are palpated for the presence of tenderness, firmness, or enlargement. The amount and quality of saliva coming from the ducts inside the mouth is assessed. The presence of dry or reddish oral mucosa is noted. The extent and pattern of dental decay are evaluated.

Salivary flow rate – In this test, the amount of saliva produced during a specified amount of time may be measured. The test is non-invasive and painless.

Scintigraphy – Performed in the hospital, this test measures 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. It is another method to measure salivary flow rate.

Biopsy of minor salivary glands – A small, shallow incision is made inside the lower lip to remove at least four of minor salivary glands. A pathologist then examines them for changes characteristic of the salivary component of Sjögren’s syndrome.

Treatment and Medications

You can do some things to relieve dry mouth temporarily. But for the best long-term dry mouth remedy, you need to address its cause.

To relieve your dry mouth:

• Chew sugar-free gum or suck on sugar-free hard candies to stimulate the flow of saliva. For some people, xylitol, which is often found in sugar-free gum or sugar-free candies, may cause diarrhea or cramps if consumed in large amounts.
• Limit your caffeine intake because caffeine can make your mouth drier.
• Don’t use mouthwashes that contain alcohol because they can be drying.
• Stop all tobacco use if you smoke or chew tobacco.
• Sip water regularly.
• Try over-the-counter saliva substitutes – look for products containing xylitol, such as Mouth Kote or Oasis Moisturizing Mouth Spray, or ones containing carboxymethylcellulose or hydroxyethyl cellulose, such as Biotene Oral Balance.
• Try a mouthwash designed for dry mouth — especially one that contains xylitol, such as Biotene Dry Mouth Oral Rinse or ACT Total Care Dry Mouth Mouthwash, which also offers protection against tooth decay.
• Avoid using over-the-counter antihistamines and decongestants because they can make your symptoms worse.
• Breathe through your nose, not your mouth.
• Add moisture to the air at night with a room humidifier

Saliva is important to maintain the health of your teeth and mouth. If you frequently have a dry mouth, taking these steps to protect your oral health may also help your condition:

• Avoid sugary or acidic foods and drinks because they increase your risk of tooth decay.
• Brush with a fluoride toothpaste — ask your dentist if you might benefit from prescription fluoride toothpaste.
• Use a fluoride rinse or brush-on fluoride gel before bedtime. Occasionally a custom-fit fluoride applicator (made by your dentist) can make this more effective.
• Visit your dentist at least twice yearly to detect and treat tooth decay or other dental problems.

If these steps don’t improve your dry mouth, talk to your doctor or dentist. The cause could be a medication or another condition.

Prevention of Xerostomia

There are a number of steps you can take to help minimize dry mouth, including:

• Sipping water or sugarless drinks often and during meals

• Avoiding drinks with caffeine, such as coffee, tea, and some sodas
• Professional recommendation for oral care products that will assist in moisturizing the mouth
• Chew sugarless gum or suck on sugarless hard candy to stimulate saliva flow citrus, cinnamon or mint-flavored candies are good choices
• Avoid tobacco or alcohol, which dry out the mouth
• Minimize spicy or salty foods, which may cause pain in a dry mouth
• Avoid sugar and acidic foods
• Using a humidifier at night