Chairside Chat: Dry Mouth

Saliva has many important functions. It helps to keep the mouth comfortable as a lubricant whilst eating or speaking and helps us taste and digest food. Saliva also keeps the teeth, the gums and the lining of the mouth healthy. Dry mouth is a subjective feeling that there is not enough saliva in the mouth. For some people this problem can be persistent and unpleasant, reducing their quality of life. Hyposalivation refers to abnormally low saliva flow. This can lead to health problems.

What causes dry mouth?

  • Drugs and medications
  • Dehydration, caused by drinking too little fluid, blood loss, chronic diarrhoea or kidney failure
  • Infection of the salivary glands– bacterial and viral (such as mumps)
  • Salivary duct obstructions (e.g. salivary stones)
  • Specific diseases– for example Diabetes, Parkinson’s disease, Lupus and AIDS
  • Injury or surgical damage to the nerves controlling the salivary glands
  • Habitual breathing through the mouth
  • Hormone changes from pregnancy/menopause
  • Anxiety


Diagnosis of dry mouth

The diagnosis of dry mouth is made by a dentist and includes assessing patient symptoms and medical history, examination of the soft and hard oral tissues and saliva tests. A common saliva test is to roll the lower lip outward, dry the labial mucosa with gauze and measure how long it takes for the mucosa to secrete saliva. If it takes longer than 60 seconds the resting saliva flow is likely to be low.

Symptoms and Signs
A person with dry mouth can experience

  • An altered sense of taste
  • Thick stringy saliva
  • Dry lips , bad breath, mouth ulcers
  • Sleep disturbances
  • Tooth erosion

Treatment of dry mouth
A dentist may recommend:

  • Saliva substitutes, dry mouth products including toothpaste, mouthwash, gums and topical agents
  • Antibiotics or anti-fungal drugs to treat infection
  • Surgery to relieve salivary gland blockages
  • Avoid cigarettes, alcohol, caffeinated drinks and spicy foods