Decreased salivary flow resulting in a dry mouth is a frequent complication of cancer treatment.

Salivary gland hypofunction (reduced saliva) is caused by both chemotherapy and/or radiation therapy. It is also a side effect of many common medications. The symptoms include dryness, burning sensation on the tongue, fissures on the tongue, atrophy of dorsal tongue surface, increased thirst, increased dental caries (dental decay) and demineralization, and candidiasis (oral yeast infections).

Decreased salivary flow can result in impaired lubrication of oral tissues leading to: (1) a difficulty in speaking and/or swallowing, (2) a decreased buffering capacity of the saliva which increases the risk of dental caries, (3) the oral flora becomes more pathogenic, (4) dental plaque levels accumulate due to a patient’s impaired oral hygiene, (5) demineralization of teeth occurs as well as tooth decay, (6) and there can be accelerated periodontal disease.

About 40% of patients receiving cancer chemotherapy report having dry mouth when getting cancer chemotherapy. It usually, however, resolves itself within a year after treatment stops. Meanwhile, more than 90% of patients who receive head and neck radiation have long-term dry mouth when the parotid gland is irradiated directly. Unfortunately, decreased salivary flow can be an irreversible problem in the case of head and neck radiation.

Additionally, pre-existing diseases such as diabetes, hypothyroidism and rheumatoid arthritis or other immune mediated diseases are also associated with decreased salivary flow and the effect of chemotherapy or head and neck radiation would be additive.

A dental examination prior to beginning cancer treatments is an important step. Dental care may also be needed more frequently during cancer treatment.

Based on salivary flow assessment (the amount of saliva), advice may include:

• Increasing one’s adequate daily fluid intake to include 64 ounces of non-caffeinated and non-alcoholic fluids (e.g., water),
• Using a soft toothbrush with a gentle toothpaste, often without sodium lauryl sulfate,
• Flossing 1 to 2 times daily,
• Taking a prescribed topical fluoride application daily
• Taking a remineralizing solution such as Caphosol which has been shown to reduce cancer treatment associated mucositis (oral sores) due to radiation or chemotherapy and/or,
• Taking a prescribed salivary stimulant such as Pilocarpine 5-7.5 mg 4 times/daily or Cevimeline 30-60 mg 3 times/daily may be helpful.
• Edentulous patients who wear dentures may also need additional advice from their dentists on disinfecting their dentures, and
• Finally, over the counter products developed for patients with dry mouth can be used frequently to improve one’s comfort level.

Related Sources:

Oral Complications of Chemotherapy and Head/Neck Radiation (PDQ). National Cancer Institute. 2007; 1-6.

Garg AK, Malo M. JADA. 1997;128: 1128-1133 http://www.drymouth.info/consumer/TreatmentForDM.asp