General Dental Informtion

Causes of dry mouth

cause of dry mouth

Dry mouth or xerostomia can be  related to physiological conditions of the patient or to environmental conditions. The physiological conditions include dental and jaw malocclusions that lead to mouth opening and dry mouth. The environmental and acquired conditions such as activity and mobility in extreme heat and failure to drink enough water also are causes of xerostomia.

Dry mouth may result from some health problems including diabetes, stroke, oral yeast infection (oral thrush), Alzheimer’s disease, or autoimmune diseases including Sjogren’s syndrome and HIV/AIDS. Snoring and open mouth breathing can also cause xerostomia.

If there is no saliva, you cannot eat even a simple biscuit without having to drink a lot of fluids. Moreover, we cannot well taste the foods, because many foods need to be dissolved in saliva so that the taste buds can receive and understand them. In the absence of saliva, teeth regularly wear out the tongue and cheeks and cause painful sores in the oral cavity. In the absence of saliva, we cannot speak easily because we may repeatedly cough, our lips stick to the surface of our teeth, and a thick foam embarrassingly accumulates around the corners of our mouth.

dry mouth side effects

Xerostomia caused by the physiological conditions of the patient

The two rows of upper and lower teeth do not connect all the way in some patients with open bite malocclusion. These patients breathe with half-open mouth and, if they do not visit an orthodontic specialist in time, will develop xerostomia or the other complications of this occlusion. Other dental and jaw malocclusions including overjet, short maxillary length, and Class 2 and 3 malocclusions also cause dry mouth because patients suffering from them cannot always breathe through the nose and unconsciously breathe with their mouth open, which will lead to dry mouth and maxillary stenosis.

Neural and physical injuries in the head and neck area can also cause xerostomia. Saliva secretion also decreases with age and the patient must drink more water and liquids to compensate for it.

Xerostomia caused by environmental factors

Dry mouth caused by environmental factors can be controlled and treated by eliminating the environmental factors some of which are as follows:  

  • Tobacco and nicotine consumption
  • Excessive alcohol, caffeine, tea and coffee consumption
  • Radiotherapy and chemotherapy
  • Consumption of neuropathic pain medications
  • Poisoning
  • Failure to drink sufficient water and liquids
  • Work and activities in warm air
  • Dental and oral infections
  • Tooth decay

dry mouth due to the patients physical condition

Treatment of dry mouth

Most dentists do not take dry mouth seriously and only advise patients to drink more fluids. What about if dry mouth is caused by Sjogren’s syndrome? Such cases of dry mouth will not improve only by drinking more fluids. Most patients with Sjogren’s syndrome gradually become isolated because of impaired speech. Some of them may feel that their tongue has enlarged and adversely affected their pronunciation. In a study conducted by Segal et al. in 2009, it was shown that patients with Sjogren’s syndrome pay for dental care three times more than normal individuals.

Dry mouth in patients with Sjogren’s syndrome may also pose problems for the dentist, exactly like recurrent dental caries along with very beautiful recent restorations. If such individuals have teeth filled with glass ionomer requiring regular local fluoride therapy, the restoration’s margin may break down, increasing the risk of tooth decay recurrence. When the patient has extensive cervical caries extended to the distal of the second molar, the story will be more complicated because the dentist needs to shave and restore them!!!


causes of dry mouth diagnosis

Home treatments for dry mouth

There was no standard protocol for dental treatment of dry mouth until 2016 when the Sjogren’s Syndrome Foundation (SSF) proposed guidelines to help prevent dental caries in patients with Sjogren’s syndrome. Local fluoride therapy can help prevent dental caries; however, this should not cause damage to glass ionomer fillings. Another way to prevent dry mouth is to stimulate salivation, by either increasing the chewing activity or taking drugs. The former is done by chewing sugar-free gums and the latter involves taking drugs such as pilocarpine Hydrochloride (Salagen) and cevimeline (Evoxac). Individuals who have extensive dental caries are recommended to use fluoride varnish, fluoride gels, or chlorhexidine mouthwashes to improve their dry mouth.

The most common and perhaps the first symptom of Sjogren’s syndrome is dry mouth, which is associated with extensive tooth decay. If a person with dry mouth is also suffering from dry eye, articular pains, and fatigue, they are most likely afflicted with Sjogren’s syndrome and need to visit an oral medicine doctor or a rheumatologist. Therefore, general dentists can play a major role in the timely diagnosis of this disease.

dry mouth treatment

Causes of dry mouth FAQ

1-Is dry mouth dangerous?

Dry mouth is not dangerous by itself. It is usually the symptom of a disease or abnormal condition in the body that requires examination and treatment. If the causal agent of dry mouth is not removed, it can lead to early tooth decay.

2-What are the complications of untreated dry mouth?

Saliva is a constituent of the body’s first line of defense. Dry mouth increases the risk of  viral diseases such as influenza and even corona. Tooth decay and headache are among the serious long-term complications of dry mouth.

3-Is dry mouth a symptom of diabetes?

One of the most common symptoms of diabetes is dry mouth (xerostomia). It is a common symptom of type 1 and 2 diabetes; however, all diabetic patients do not experience it.

4-What are the diseases that cause dry mouth?

Diabetes, thyroid diseases, stroke, oral yeast infection (oral thrush), or Alzheimer’s disease are some of the diseases that cause dry mouth. Autoimmune diseases including Sjogren’s syndrome and HIV/AIDS also lead to xerostomia. Snoring and open mouth breathing and excessive consumption of tobacco and alcohol also cause dry mouth.

5-Why do diabetic patients develop xerostomia?

Diabetic patients are susceptible to dry mouth and yeast infections such as thrush because of their high blood and salivary glucose levels. Low water content in the body of diabetic patients, smoking, and consumption of some medications are among the other reasons.

Dr Abdolreza Jamilian Orthodontist

About Dr Abdolreza Jamilian Orthodontist

Dr. Jamilian, an orthodontist, has a specialized fellowship in orthodontic surgery and maxillofacial abnormalities and is a full-time professor in the orthodontics department of the Dentistry School of the Islamic Azad University. He is member of Iranian and European Board of Orthodontics (EBO) and is a member of the Iranian, American and European Orthodontists Association.

Leave a Reply

Your email address will not be published. Required fields are marked *