Dry Mouth

Original Editor - Wendy Walker.

Lead Editors - Wendy Walker and Tarina van der Stockt

Introduction

The medical term for dry mouth is Xerostomia, which is described as being "the subjective feeling of oral dryness, which is often (but not always) associated with hypofunction of the salivary glands".

Signs & Symptoms

  • sensation of dryness/stickiness in the mouth
  • burning sensation in the mouth
  • tongue “sticking” causing difficulty in speaking
  • difficulty moving food in mouth when eating, especially dry food such as bread
  • increased sores/mouth ulcers
  • dry, sore and cracked lips

Anatomy

2408 Salivary Glands.jpg

This image shows the 3 main salivary glands.


The Sublingual and Submandibular glands are supplied by the Facial Nerve (7th Cranial Nerve); the Parotid gland is supplied by the Glossopharyngeal Nerve (9th Cranial Nerve).


In addition to these 3, there are more than 800 minor salivary glands spread out throughout the oral mucosa. These minor salivary glands are supplied by the Facial Nerve.


It is worth noting that in the region of 65-70% of saliva in the mouth is produced by the submandibular glands, even though as you can clearly see in the image, they are much smaller than the parotid glands.

Causes

  1. Age: dry mouth becomes more common with age
  2. Facial Palsy: in cases of facial palsy, dry mouth can occur as two of the three main salivary glands receive their parasympathetic nerve supply from the facial nerve: the sublingual and glossopharyngeal glands. (The parotid gland is not innervated by the facial nerve, so is unaffected.)
  3. Medications: some commonly prescribed medications (particularly those used for control of high blood pressure and treatment of depression)can cause dry mouth, so check the information leaflet to see if this is one of the side effects
  4. Medical conditions: there are a number of medical conditions which cause dry mouth, with diabetes, and Sjorgren’s Syndrome being two of the most common
  5. Other treatment: radiotherapy treatment to the head or neck

Advice

  • Sip water frequently throughout the day - although this is not the same consistency as saliva, it does temporarily help relieve the symptoms
  • Avoid or reduce consumption of caffeine, particularly in coca cola drinks or strong coffee, as these tend to increase mouth dryness
  • Reduction of alcohol consumption is also useful
  • Stopping or reducing smoking is very helpful
  • If struggling to chew foods, choose meals with sauces or gravy
  • Avoid mouthwashes containing menthol, alcohol or foaming agents as these ingredients all cause further reduction in saliva
  • Some people find that using a humidifier in the bedroom at night helps to keep the air full of moisture
  • Consider using over-the-counter medication

NB Sometimes people with dry mouth problems are advised to chew gum as a means of increasing saliva production. However, in cases of facial palsy it is considered by many experts to be inadvisable to use gum as this often tends to increase synkinesis.

Dental care

People with dry mouth should increase their dental care regime, as they are at increased risk of both tooth decay and gum disease.
For people with facial palsy, it is important to provide extra care to the teeth and gums on the palsy side of the mouth, as saliva provides an important protection against both tooth decay and gum disease.

Resources

This page on Dry Mouth in Older People is provided by the British Dental Foundation

The British charity Facial Palsy UK has a useful page on advice for people with facial palsy and dry mouth