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Xerostomia (Dry Mouth)

Man with open mouth

What is xerostomia?

Xerostomia is another name for dry mouth caused by reduced or absent saliva flow.

Xerostomia is a symptom rather than a medical condition.

What causes xerostomia?

Xerostomia may be caused by:

  • Breathing with your mouth open
  • Medical conditions such as dementia, diabetes, Sjogren's syndrome, or stroke
  • Medications, such as antidepressants, antipsychotics, antihistamines, chemotherapy, diuretics, and sedatives
  • Nerve damage to the head and neck area
  • Problems with the salivary gland
  • Radiation to the head and neck
  • Snoring
  • Tobacco, Alcohol, or recreational drug use

Saliva contains the digestive enzyme ptyalin, a lubricating aid called mucin, large amounts of potassium and bicarbonate ions and other electrolytes and antimicrobial constituents. It is secreted from the salivary glands and has a pH of between 6 and 7.4. We have three paired major salivary glands (the parotid, submandibular, and sublingual glands) as well as hundreds of minor salivary glands.

The production of saliva is mediatic by muscarinic receptors, particularly M3. M3 receptors are located in many other glands of the body, so in addition to stimulating the secretion of saliva, they also help regulate insulin release from the pancreas and digestive secretions from the stomach.

Production of saliva is also influenced by stimuli such as taste and smell and mood conditions such as anxiety or depression. Saliva is important for reducing the risk of infection through its antimicrobial action, cleansing, controlling the pH of the oral mucosa, removing food debris, lubricating the oral cavity and remineralization of teeth.

What are the symptoms of xerostomia?

Symptoms may vary depending on the severity but may include:

  • Dry mouth
  • Bad breath
  • Burning sensation in the mouth
  • Complaints of the tongue sticking to the roof of the mouth or a painful tongue
  • Constant sore throat
  • Difficulty speaking and swallowing
  • Difficulty wearing dentures or prone to sores from dentures rubbing
  • Dry foods, such as crackers or cereals become difficult to chew and swallow
  • Dry nasal passages
  • Gum disease
  • Hoarseness
  • Increased incidence of plaque, tartar, dental caries, and tooth loss
  • Increased need to drink water, especially at night
  • Lip inflammation and fissuring
  • Parotid gland enlargement
  • Recurring oral candidiasis
  • Salivary gland infections
  • Taste disorders
  • Ulcers of the tongue or oral mucosa
  • Women may notice that lipstick constantly adheres to their front teeth

How is xerostomia diagnosed?

If you have symptoms of xerostomia, see your doctor. Your doctor will ask you about your symptoms and your medical and medication history. Your doctor will look inside your mouth and may measure the flow rate of your saliva.

Further tests, such as sialography, an imaging technique that looks for stones or masses in the salivary glands may be conducted.

How is xerostomia treated?

Treatment for xerostomia varies depending on the cause but may include:

  • Being vigilant with oral hygiene to reduce the risk of dental caries and considering the use of fluoride gels or chlorhexidine mouthwashes
  • Switching medications to one that is less likely to cause a dry mouth, or reducing the dosage of a medication
  • Treating any underlying diseases if present
  • Using a saliva stimulant, such as xylitol-containing candy or chewing gum, or prescription products such as pilocarpine or cevimeline
  • Using a saliva substitute that mimics natural saliva. These usually contain carboxymethylcellulose or hydroxyethylcellulose to increase viscosity, minerals such as calcium, phosphate, and fluoride, and other ingredients such as preservatives or flavoring agents
  • Treating oral candidiasis if present
  • Regular dental check-ups every 6 months
  • Soaking dentures overnight in sodium hypochlorite solution (acrylic dentures) or chlorhexidine (metal dentures)
  • Avoiding sugary or acidic foods or beverages
  • Applying lip lubricants regularly

Article references

  1. Xerostomia. The Oral Cancer Foundation. 2020 https://oralcancerfoundation.org/complications/xerostomia/
  2. Xerostomia. Mayo Clinic. 2018 https://www.mayoclinic.org/diseases-conditions/dry-mouth/symptoms-causes/syc-20356048
  3. Managing xerostomia and salivary gland hypofunction. American Dental Association. 2015 https://www.ada.org/~/media/ADA/Science%20and%20Research/Files/CSA_Managing_Xerostomia.pdf?la=en