Does dry mouth cause bad breath?

Does it ever. Contrary to the way many toothpaste and chewing gum commercials may make it seem, dry mouth is one of the most common contributors to bad breath. While tooth decay, pungent food, gingivitis, postnasal drip, cigarettes and tonsil stones all certainly do their part, a dry palate is one of the most pernicious origins of oral odor, precisely because most people simply don't think about it.

After all, which sounds worse - gum disease, plaque buildup, food residue or dry mouth? In terms of dental care and halitosis, the latter may sound like child's play compared to the rest. However, dry mouth can cause bad breath, and worse.

Take morning breath, a scent that most people are grudgingly familiar with. If you've ever slept with your mouth open, you probably know how powerful this kind of halitosis can be. Many an early kiss has been aborted at the detection of morning breath, and for good reason.

A dry mouth provides a fertile plain for billions of anaerobic bacteria living on your tongue, teeth and palate. Without saliva to keep them in check, they multiply, releasing volatile sulfur compounds (VSCs) as a byproduct of their digestion. The end result is simple: you wake up with a mouth smelling like a gym sock.

Sleeping with the mouth open isn't the only cause of dry mouth. A number of common habits can lead to a parched palate, including alcohol consumption, smoking, aerobic exercise, prolonged speech or anxiety. Any activity that forces air, hot gases or moisture-drying alcohol over the tongue is a surefire way to court bad breath.

When your mouth feels especially arid, it may be a good idea to use specialty breath freshening products that moisten the palate while neutralizing VSCs. Likewise, a daily oral care probiotic pill can gradually replace dryness-loving anaerobic bacteria with less irritating strains.

Dental experts also note that chronic dry mouth, a condition known as xerostomia, may be a symptom of a medical condition. A report in the journal Odontology states that xerostomia is often caused by prescription medications, head and neck radiation, or inherited glandular disorders.

Also, the mouth naturally produces less saliva with age, which is why dry mouth is more common among the elderly, according to a study in the Ear, Nose and Throat Journal. However, a paper in the Journal of the American Dental Association warns that left untreated, xerostomia can lead to tooth decay, gum disease and - what else - bad breath.