Dry Mouth Syndrome

Dry mouth syndrome

About one in every four Australians has dry mouth syndrome, which is when there is not enough

saliva (spit) in the mouth. A dry mouth is a symptom of an underlying problem, rather than a

disease in itself.

Various factors can cause a persistently dry mouth, including prescription medications, medical

treatments and certain autoimmune diseases such as Sjogren’s syndrome. Treatment includes

products that help to moisten the mouth. Dry mouth syndrome is also called xerostomia.

Symptoms

The signs and symptoms of dry mouth may include:

• Saliva that feels thick or stringy

• Rough, dry tongue

• The tongue tending to stick against the roof of the mouth

• Problems with chewing or swallowing (particularly dry foods such as biscuits)

• Bad breath

• Mouth ulcers

• Dry and cracked lips

• Susceptibility to oral thrush infections

• High rate of tooth decay

• A prickly burning sensation in the mouth.

Associated symptoms

Depending on the cause, dry mouth syndrome may be associated with symptoms and signs outside

of the mouth, including:

• Dry and itchy eyes

• Dry nose or throat

• Frequent coughing

• Reduced sense of smell

• Constipation

• Joint pains or stiffness

• Generally feeling unwell

• Unexplained weight loss

• In women, frequent vaginal thrush infections.

Salivary glands explained

The salivary glands are located around the mouth and throat. These glands make saliva, which is

pumped into the mouth along tiny channels called salivary ducts. The salivary glands include:

• Parotid – located in front of the ear and behind the angle of the jaw.

• Submandibular – located beneath the tongue on both sides of the jaw (mandible).

• Sublingual – located in the floor of the mouth.

• Minor salivary glands – found in various locations around the mouth, including the inner

cheeks and throat.

A steady flow of saliva keeps the mouth moist at all times. Chewing and swallowing food increases

the flow of saliva – simply looking at appetising food can also cause an increased saliva flow.

The protective role of saliva

A dry mouth significantly increases the risk of tooth decay. This is because saliva:

• Contains components that can directly attack decay causing bacteria

• Has antifungal properties

• Helps to destroy viruses

• Neutralizes the acids produced by plaque

• Contains phosphorus and calcium. These substances are vital to the ongoing process of remineralisation,

which is the rebuilding of tooth enamel (the hard surface layer that protects

the tooth)

• Moistens food, which enables comfortable swallowing

• Helps with the formation of particular sounds in speech

• Boosts sensation inside the mouth and allows, for example, the experience of pain, food

texture and taste.

Pattern of tooth decay

Poor oral hygiene and a sugary diet tend to cause caries (tooth decay) in the biting surfaces and in

between teeth. However, dry mouth syndrome causes a different pattern of tooth decay. The decay

tends to start along the gumline (gingival margin) and, in some cases, the gums drawback to

expose the underlying tooth layer (dentine).

Unlike enamel, dentine offers little resistance to caries bacteria and decay tends to be rapid. Decay

of the exposed dentine is sometimes called ‘root caries’.

Decay may also be seen on the lower front teeth that are normally well protected by saliva

produced from beneath the tongue.

Causes

Many different conditions, some short-term and others long-term, can disrupt the production of

saliva. These conditions may include:

• Drugs – about 600 drugs, both legal and illegal, are known to cause dry mouth. These

drugs include antihistamines, high blood pressure medications, sedatives, decongestants,

analgesics, antidepressants and illegal drugs such as cocaine.

• Dehydration – drinking too little fluid can cause thick saliva and a dry mouth. Other

causes of dehydration include medical conditions such as blood loss, chronic diarrhoea or

kidney failure.

• Infection – a bacterial or viral infection of the salivary glands (such as mumps) can cause

inflammation and restrict saliva production.

• Sjogren’s syndrome – this is a reasonably common autoimmune disease that mainly

affects the eyes and salivary glands, but can also affect the sweat glands.

• Salivary duct obstructions – for example, tiny stones made from saliva minerals may

lodge in the salivary ducts and restrict saliva flow.

• Certain diseases – can be the cause such as AIDS, amyloidosis, cerebral palsy, diabetes,

Parkinson’s disease, primary biliary cirrhosis and lupus.

• Nerve problems – the function of the salivary glands is controlled by facial nerves. Injury

or surgical damage to these nerves, for example, may reduce saliva production.

• Some cancer treatments – such as chemotherapy or radiotherapy (if directed at the

head or neck) may temporarily reduce the ability of salivary glands to make saliva.

• Other causes – may be responsible, such as habitually breathing through the mouth, for

example, in the case of a persistently stuffy nose or blocked sinuses, or hormone changes

from pregnancy or menopause.

Diagnosis

Diagnosis of dry mouth syndrome may include:

• Physical examination – the inner cheeks appear dry and rough, rather than moist and

shiny.

• Tooth examination – the doctor or dentist may check the pattern of tooth decay.

• Saliva tests – for example, a typical saliva test involves rolling out the lower lip and

patting it dry. Normally, saliva should re-moisten the lower lip within half a minute or so.

• Medical history – to check for diseases or medicines that could be drying out your mouth.

Treatment

Treatment depends on the cause, but may include:

• Changes to medicines – if you are taking a medicine that causes dry mouth as a side

effect, the doctor may be able to alter the dose or prescribe an alternative medicine.

• Saliva substitutes – your doctor or dentist can prescribe an artificial saliva substitute.

Use strictly as directed.

• Dry mouth products – these products contain a variety of agents such as lubricants that

may help treat your dry mouth. The product range includes toothpaste, mouthwash, gums

and topical gels. Speak to your dentist for specific recommendations.

• Antibiotics and antifungal drugs – to treat any infection.

• Surgery – salivary gland blockages, such as stones, are usually treated with surgery.

• Other treatments, if required – any underlying condition, such as Sjogren’s syndrome or

diabetes, needs appropriate medical treatment.

Prevention – dietary suggestions

Be guided by your doctor and dentist, but general dietary suggestions include:

• Eat chewy foods to stimulate the flow of saliva.

• Chew food thoroughly before swallowing.

• Include watery foods in your daily diet such as pureed fruits and jellies.

• Avoid crunchy foods that could injure the mouth, such as crackers or potato crisps.

• Avoid acidic foods and beverages such as soft drinks, citrus fruits and citrus fruit juices to

protect your tooth enamel.

• Restrict sugary foods and drinks or avoid them altogether.

• Avoid mint lollies and mint mouthwashes, as these products tend to aggravate dry mouth

tissue and increase the risk of tooth decay. It’s better to ask your dentist about non-mint

flavoured mouthwashes.

• Avoid any substance that increases mouth dryness such as cigarettes, alcohol, caffeinated

drinks and spicy foods.

• Chew sugar-free gum between meals to promote the flow of saliva.