Dry mouth resulting from insufficient production of saliva is called Xerostomia. Often patients complain of subjective symptoms more than clinical presentation like rampant caries. It causes significant discomfort for the patient, in that the tissues feel dry, abrasive and swallowing can become difficult.
Saliva is the watery fluid secreted into the oral cavity by the salivary glands. It contains proteins, and mucins which are lubricating agents. It also possesses antibacterial and anti-fungal properties because of its components like immunoglobulins, lactoferrin, thiocyanate etc. Saliva also contains a significant amount of potassium and bicarbonate, and traces of sodium and chloride. When salivary production decreases due to any reason causing dryness and soreness of oral tissues, it results in a condition called xerostomia.
Causes of Xerostomia
A number of causes have been identified as resulting in dry mouth. The most common causes are:
- Physical injury to the salivary glands
- Underlying diseases such as Sjogren’s syndrome, uncontrolled diabetes and Lambert-
- Eaton’s syndrome
- Sarcoidosis (noncaseating granulomas in the salivary glands)
- Amyloidosis (amyloid deposits in the salivary glands)
- HIV infection particularly in children
- Rheumatoid arthritis, systemic lupus erythematosus (SLE), scleroderma, cystic fibrosis, bone marrow transplantation, nutritional deficiencies, Bell’s palsy, thyroid diseases
- Depression or anxiety can result in dry mouth
- Alzeimer’s or Parkinson’s may also result in decreased secretion of saliva
- Excessive alcohol consumption leading to cirrhosis
- Excessive smoking
- Breathing continuously through the mouth instead of the nose
- Medications such as antidepressants, amphetamines and antihistamines
- Drug abuse – methamphetamine, cannabis and heroin use
Xerostomia, other than being uncomfortable causes a host of other problems such as burning sensation in the mouth, soreness of the oral tissues and throat, difficulty speaking and swallowing, halitosis (foul mouth odor), rampant tooth decay or caries and result in the periodontal and other soft tissues being susceptible to ulceration and infection. If untreated for a long time, it can result in tooth loss and thrush.
Patients often complain about altered taste sensation (dysgeusia), and difficulty in eating and swallowing, especially foods which are dry and devoid of any moistness or lubrication. Tooth loss leads to denture fabrication, but it leads to a new problem. Denture retention is severely affected in patients having less saliva production as there is nothing acting as a retentive agent. It can therefore result in dentures falling out of the mouth while speaking, or eating, denture soreness and subsequent refusal to wear the dentures at all.
The tongue becomes fissured, and painful (glossodynia). The lips may become fissured and bleeding. Other problems include parotid gland enlargement, and salivary gland infection.
Diagnosis can be done by a number of clinical and laboratory tests including careful patient history analysis, sialometry, and the “lipstick sign” in women, where the lipstick often sticks to the front teeth in case of xerostomia.
- There is no pooling of saliva in the floor of the mouth
- The saliva may appear thick, stringy and ropy
- Diagnostic instruments may stick to the oral tissues, especially the buccal mucosa
- Rampant cervical caries (decay near the gum line of the teeth) may be seen.
- Measurement of salivary flow rate by sialometry. The saliva is stimulated by citric acid application. Normal range of salivary flow rate is 0.3 to 0.5 mL/min/gland (resting) and 1 to 2 mL/min/gland (stimulated). Salivary flow rate of less than 0.1 mL/min/gland is considered as a sign of xerostomia
- Sialography or salivary gland imaging is done to rule out salivary gland diseases
Treatment of Xerostomia
Treatment of xerostomia or dry mouth is targeted more towards relieving the symptoms and preventing infection and caries rather than treating the cause itself. Most of the time the cause of xerostomia can’t be corrected. If it is due to dehydration, sipping on water can help but if the cause is not dehydration then sipping on water will not improve the production of saliva and be a source of increased discomfort for the patient.
A more satisfying option is to frequently sip on a non-carbonated sugarless drink or chewing on a xylitol gum.
- Pilocarpine and cevimeline are anticholinergic agents which are also used in treatment of dry mouth.
- Changing the dry mouth causing medication can be effective in case the medication being used by the patient had anticholinergic effects
- Using a cellulose based salivary substitute results in alleviation of the discomfort
- Calcium phosphate rinses help reduce discomfort in patients with Sjogren’s syndrome or those suffering from medication usage
- Periodic fluoride application to prevent tooth decay
- Anti-fungal agents can be used to prevent candida infection
- Lactoferrin containing mouthwashes also possess fungistatic properties
On the personal front a patient can take a number of precautions to maintain their oral hygiene. Regular brushing with a fluoride based toothpaste, using a mouthwash and flossing to tackle interdental areas can significantly reduce plaque formation, cavities and periodontal or gum problems. Avoid products containing sodium lauryl sulphate as they can result in apthous ulcers and soreness. Dentures should not be worn at night while sleeping and should be kept immersed in water.