Dry mouth: What causes this common agent of bad breath?

Commercials for mouthwash and toothpaste often depict their products cleaning away food residue and eliminating bad breath. Similarly, breath mint advertisements may promise to relieve the odors associated with coffee or garlic, easing tension during close or awkward social situations. What they rarely add is that one of the most common causes of halitosis, or dry mouth, has very little to do with food or beverages at all.

When the oral environment dries out, anaerobic bacteria that live in the mouth begin to multiply rapidly and emit sulfuric compounds as they digest proteins found on the tongue, gums and palate. These sulfuric compounds are responsible for a considerable amount of bad breath, smelling as they do like rotten food.

Moistening the mouth with specialty breath freshening products, like rinses or tablets, can both eliminate the dryness bacteria thrive on and neutralize their odors. Below are some common and uncommon causes of dry mouth.

Sleeping with the mouth open - Virtually everyone has suffered from bad breath caused by sleeping with the mouth hanging open. Morning breath is a particularly pungent form of dry mouth-caused halitosis because bacteria have some or even the whole night to multiply, feed and cause odor. A telltale sign of bacterial growth is whitish material on the tongue or lips. Rinsing the mouth out with water in the morning is a good way to reduce oral odor, though eliminating it may require using a breath freshening product.

Smoking - The smoke and hot gases associated with tobacco or marijuana use can very quickly dry out the tongue and throat. Smoking poses a double threat to oral freshness too, in that it leaves behind tar particles that may immediately be smelled on the breath.

Xerostomia - According to the University of Illinois, Chicago’s Department of Periodontology, xerostomia is not a disease but the symptom of certain diseases. Also called cottonmouth, xerostomia occurs when the salivary glands reduce or even cease production of moisture in the mouth. It can be caused by diabetes, anxiety, dehydration, damage to particular facial nerves, and even Sjögren's syndrome, an autoimmune condition that attacks the salivary and tear-producing glands. Furthermore, certain medications can cause xerostomia as a side effect.

Exercise - Even vigorous exercise can cause dry mouth, since heavy respiration, particularly in the winter months, may blast the tongue and throat with bursts of very dry air. Beyond drinking plenty of fluids, it may be advisable to rinse the mouth after exercise with a specialty breath freshener to neutralize bad breath odors.