BAD BREATH

 

Halitosis, oral malodor (scientific term), breath odor, foul breath, fetor oris, fetor ex ore, or most commonly bad breath are terms used to describe noticeably unpleasant odors exhaled in breathing – whether the smell is from an oral source or not.

Halitosis has a significant impact — personally and socially — on those who suffer from it or believe they do (halitophobia), and is estimated to be the 3rd most frequent reason for seeking dental aid, following tooth decay and periodontal disease.

Though the causes of breath odor are not entirely understood, most unpleasant odors are known to arise from proteins trapped in the mouth which are processed by oral bacteria. There are over 600 types of bacteria found in the average mouth. Several dozens of these can produce high levels of foul odors when incubated in the laboratory.

The most common location for mouth-related halitosis is the tongue. Large quantities of naturally-occurring bacteria are often found on the posterior dorsum of the tongue, where they are relatively undisturbed bynormal activity. This part of the tongue is relatively dry and poorly cleansed, and bacterial populations can thrive on remnants of food deposits, dead epithelial cells and postnasal drip. The convoluted microbial structure of the tongue dorsum provides an ideal habitat for anaerobic bacteria, which flourish under a continually-forming tongue coating of food debris, dead cells, postnasal drip and overlying bacteria, living and dead. When left on the tongue, the anaerobic respiration of such bacteria can yield either the putrescent smell of indole, skatole, polyamines, or the "rotten egg" smell of volatile sulfur compounds (VSCs) such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide.

The odors are produced mainly due to the anaerobic breakdown of proteins into individual amino acids, followed by the further breakdown of certain amino acids to produce detectable foul gases. For example, the breakdown of cysteine and methionine produce hydrogen sulfide and methyl mercaptan respectively. Volatile sulfur compounds have been shown to be statistically associated with oral malodor levels, and usually decrease following successful treatment.

Other parts of the mouth may also contribute to the overall odor, but are not as common as the back of the tongue. These locations are, in descending prevalence order: inter-dental and sub-gingival niches, faulty dental work, food-impaction areas in-between the teeth, abscesses and unclean dentures.