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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.
In most cases (85-90%), bad breath originates in the mouth itself. The intensity of bad breath differs during the day, as a function of oral dryness, (which may be due to stress or fasting), eating certain foods (such as garlic, onions, meat, fish and cheese), obesity, smoking and alcohol consumption. Because the mouth is dry and inactive during the night, the odor is usually worse upon awakening ("morning breath"). Bad breath may be transient, often disappearing following eating, brushing one's teeth, flossing, and rinsing with specialised mouthwash.
Bad breath may also be persistent (chronic bad breath), which is a more serious condition, affecting some 25% of the population in varying degrees. It can negatively affect the individual's personal, social and business relationships, leading to poor self-esteem and increased stress. This condition is usually caused by the metabolic activity of certain types of oral bacteria.
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 by normal 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.
There is some controversy over the role of periodontal diseases in causing bad breath. Whereas bacteria growing below the gumline (subgingival dental plaque) have a foul smell upon removal, several studies reported no statistical correlation between malodor and periodontal parameters.
The second major source of bad breath is the nose. In this instance, the odor exiting the nostrils has a pungent odor which differs from the oral odor. Nasal odor may be due to sinus infections or foreign bodies.
Putrefaction from the tonsils is generally considered a minor cause of bad breath, contributing to some 3-5% of cases. Although approximately 5% of the population suffer from small bits of calcified matter in tonsillar crypts called tonsilloliths, which smell extremely foul when released, they do not necessarily cause bad breath.
Because these conditions are rare, may not display bad breath at all, and will most likely show additional characters (which are more conclusive, diagnostically, than the breath odor), people suffering from halitosis should not immediately conclude that they suffer from these conditions or diseases just by deducing from the breath odor alone.
Most researchers consider the stomach as a very uncommon source of bad breath (except in belching). The esophagus is a closed and collapsed tube, and continuous flow (as opposed to a simple burp) of gas or putrid substances from the stomach indicates a health problem - such as reflux or a fistula between the stomach and the esophagus - which will demonstrate more serious manifestations than just foul odor.
Self diagnosis and home diagnosis
Scientists have long thought that smelling one's own breath odor is often difficult due to habituation, although many people with bad breath are able to detect it in others. Research has suggested that self-evaluation of halitosis isn't easy because of preconceived notions of how bad we think it should be. Some people assume that they have bad breath because of bad taste (metallic, sour, fecal, etc), however bad taste is considered a poor indicator.
For these reasons, the simplest and most effective way to know whether one has bad breath is to ask a trusted adult family member or very close friend ("confidant"). If the confidant confirms that there is a breath problem, he or she can help determine whether it is coming from the mouth or the nose, and whether a particular treatment is effective or not.
One popular home method to determine the presence of bad breath is to lick the back of the wrist, let the saliva dry for a minute or two, and smell the result. This test results in overestimation, as concluded from research, and should be avoided. A better way would be to lightly scrape the posterior back of the tongue with a plastic disposable spoon and to smell the drying residue. A spouse, family member, or close friend may be willing to smell one's breath and provide honest feedback. Home tests are now available which use a chemical reaction to test for the presence of polyamines and sulfur compounds on tongue swabs, but there are few studies showing how well they actually detect the odor. Furthermore, since breath odor changes in intensity throughout the day depending on many factors, multiple testing may be necessary.
If bad breath is persistent, and all other medical and dental factors have been ruled out, specialised testing and treatment is required. Hundreds of dental offices and commercial breath clinics now claim to diagnose and treat bad breath. They often use some of several laboratorial methods for diagnosis of bad breath:
Although such instrumentation and examinations are widely used in breath clinics, the most important measurement of bad breath (the gold standard) is the actual sniffing and scoring of the level and type of the odor carried out by trained experts ("organoleptic measurements"). The level of odor is usually assessed on a six point intensity scale.
Home care and treatment
Currently, chronic halitosis is not very well understood by most physicians and dentists, so effective treatment is not always easy to find. Six strategies may be suggested:
Mouthwashes often contain antibacterial agents including cetylpyridinium chloride, chlorhexidine, zinc gluconate, essential oils, and chlorine dioxide. They may also contain alcohol, which is a drying agent and may worsen the problem. Rinses in this category include Scope™ and Listerine™.
Other solutions rely on odor eliminators like oxidizers to eliminate existing bad breath on a short-term basis. Rinses in this category include TheraBreath™, Closys™ and others.
Bad breath may be temporarily reduced by using a hydrogen peroxide rinse. Hydrogen peroxide at a concentration of 1.5% can be taken as an oral antiseptic by gargling 10 ml, about two teaspoons. Hydrogen peroxide is commonly available at a concentration of 3% and should be diluted to 1.5% by mixing it with an equal volume of water. Hydrogen peroxide is a powerful oxidizer which kills most bacteria, including useful aerobic bacteria. Prolonged use of hydrogen peroxide may be harmful. Concentrated hydrogen peroxide (>50%) is corrosive, and even domestic-strength solutions can cause irritation to the eyes, mucous membranes and skin. Swallowing hydrogen peroxide solutions is particularly dangerous, as decomposition in the stomach releases large quantities of gas (10 times the volume of a 3% solution) leading to internal bleeding. Inhaling over 10% can cause severe pulmonary irritation.
A relatively new approach for home-care of bad breath is by oil-containing mouthwashes. The use of essential oils has been studied, was found effective and is being used in several commercial mouthwashes, as well as the use of two-phase (oil:water) mouthwashes, which have been found to be effective in reducing oral malodor.
Halitophobia (delusion halitosis)
Some one quarter of the patients seeking professional advice on bad breath suffer from a highly exaggerated concern of having bad breath, known as halitophobia, delusional halitosis, or as a manifestation of Olfactory Reference Syndrome. These patients are sure that they have bad breath, although many have not asked anyone for an objective opinion. Halitophobia may severely affect the lives of some 0.5-1.0% of the adult population. Only few psychologists and health professionals have tried to come to terms with this debilitating and difficult-to-treat emotional problem.
In 1996, an international scientific organization (The International Society for Breath Odor Research, ISBOR) was formed to promote multidisciplinary research on all aspects of breath odors. The seventh international conference on breath odor took place in August, 2007 in Chicago, and the next conference is expected to take place in 2009 in Dortmund, Germany.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Halitosis". A list of authors is available in Wikipedia.|