Halitosis/Chronic Bad Breath

Halitosis or bad breath occurs when noticeably unpleasant odors are exhaled in breathing. Halitosis is estimated to be the third most frequent reason for seeking dental aid, following tooth decay and periodontal disease.


Tongue


The most common location for mouth related halitosis is the tongue. Tongue bacteria produce malodorous compounds and fatty acids, and account for 80 to 90% of all cases of mouth-related bad breath. 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 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 epithelial cells, postnasal drip and overlying bacteria, living and dead. When left on the tongue, theanaerobic 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 ashydrogen sulfide, methyl mercaptan, Allyl methyl sulfide, and dimethyl sulfide.


Cleaning the tongue


The most widely-known reason to clean the tongue is for the control of bad breath. Methods used against bad breath, such as mints, mouth sprays, mouthwash or gum, may only temporarily mask the odors created by the bacteria on the tongue, but cannot cure bad breath because they do not remove the source of the bad breath. In order to prevent the production of the sulfur-containing compounds mentioned above, the bacteria on the tongue must be removed, as must the decaying food debris present on the rear areas of the tongue. Most people who clean their tongue use a tongue cleaner (tongue scraper), or a toothbrush.


Mouth


There are over 600 types of bacteria found in the average mouth. Many of these can produce high levels of foul odors when incubated in the laboratory. The odors are produced mainly due to the 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 order of descending prevalence: inter-dental and sub-gingival niches, faulty dental work, food-impaction areas in between the teeth, abscesses, and unclean dentures. Oral based lesions caused by viral infections like Herpes Simplex and HPV may also contribute to bad breath.


Gum disease


There is some controversy over the role of periodontal diseases in causing bad breath. However, advanced periodontal disease is a common cause of severe halitosis. Waste products from the anaerobic bacteria growing below the gumline (subgingival) have a foul smell and have been clinically demonstrated to produce a very intense bad breath. Removal of the subgingival calculus (i.e. tartar or hard plaque) and friable tissue has been shown to improve mouth odor considerably. This is accomplished by subgingival scaling and root planing and irrigation with an antibiotic mouth rinse.


Nose


The second major source of bad breath is the nose. In this occurrence, the air exiting the nostrils has a pungent odor that differs from the oral odor. Nasal odor may be due to sinus infections or foreign bodies.


Tonsils


In general, putrefaction from the tonsils is considered a minor cause of bad breath, contributing to some 3–5% of cases. Approximately 7% of the population suffer from small bits ofcalcified matter in tonsillar crypts called tonsilloliths that smell extremely foul when released and can cause bad breath.


Esophagus


The lower esophageal sphincter, which is the valve between the stomach and the esophagus, may not close properly due to a Hiatal Hernia or GERD, allowing acid to enter the esophagus and gases escape to the mouth. A Zenker’s diverticulum may also result in halitosis due to aging food retained in the esophagus.


Stomach


The stomach is considered by most researchers 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 serious enough to be bringing up stomach contents or a fistula between the stomach and the esophagus—which will demonstrate more serious manifestations than just foul odor.


In the case of allyl methyl sulfide (the byproduct of garlic’s digestion), odor does not come from the stomach, since it does not get metabolized there.


Systemic diseases


There are a few systemic (non-oral) medical conditions that may cause foul breath odor, but these are extremely infrequent in the general population. Such conditions are:


  1. Fetor hepaticus: an example of a rare type of bad breath caused by chronic liver failure.
  2. Lower respiratory tract infections (bronchial and lung infections).
  3. Renal infections and renal failure.
  4. Carcinoma.
  5. Trimethylaminuria (“fish odor syndrome”).
  6. Diabetes mellitus.
  7. Metabolic conditions, e.g. resulting in elevated blood dimethyl sulfide (Dimethylsulfidemia).

Individuals afflicted by the above conditions often show additional, more diagnostically conclusive symptoms than bad breath.


Halitophobia (Delusion Halitosis)


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.


Management


Chronic halitosis is not well understood by most physicians and dentists, so effective treatment is not always easy to find. The following strategies may be suggested:


  1. Gently cleaning the tongue surface twice daily is the most effective way to keep bad breath in control; that can be achieved using a tooth brush, tongue cleaner or tongue brush/scraper to wipe off the bacterial biofilm, debris, and mucus. An inverted teaspoon may also do the job. Scraping or otherwise damaging the tongue should be avoided, and scraping of the V-shaped row of taste buds found at the extreme back of the tongue should also be avoided. Brushing a small amount of antibacterial mouth rinse or tongue gel onto the tongue surface will further inhibit bacterial action.
  2. Eating a healthy breakfast with rough foods helps clean the very back of the tongue.
  3. Chewing gum: Since dry-mouth can increase bacterial buildup and cause or worsen bad breath, chewing sugarless gum can help with the production of saliva, and thereby help to reduce bad breath. Chewing may help particularly when the mouth is dry, or when one cannot perform oral hygiene procedures after meals (especially those meals rich in protein). This aids in provision of saliva, which washes away oral bacteria, has antibacterial properties and promotes mechanical activity which helps cleanse the mouth. Some chewing gums contain special anti-odor ingredients. Chewing on fennel seeds, cinnamon sticks, mastic gum, or fresh parsley are common folk remedies.
  4. Gargling right before bedtime with an effective mouthwash. Several types of commercial mouthwashes have been shown to reduce malodor for hours in peer-reviewed scientific studies. Mouthwashes may contain active ingredients that are inactivated by the soap present in most toothpastes. Thus it is recommended to refrain from using mouthwash directly after toothbrushing with paste.

Mouthwashes


There has not been a single documented medical case of successfully cured chronic halitosis using any of the currently available mouthwashes. However, a 2008 systematic review determined the efficacy of antibacterial mouthrinses for treating bad breath.Mouthwashes often contain antibacterial agents including cetylpyridinium chloride, chlorhexidine(which can cause temporary staining of the teeth),zinc gluconate, essential oils, and chlorine dioxide. Zinc and chlorhexidine provide strong synergistic effect. They may also contain alcohol, which is a drying agent. Other solutions rely on odor eliminators, such as oxidizers, to eliminate existing bad breath on a short-term basis.


A new approach for home treatment of bad breath is the use of oil-containing mouthwashes and two-phase (oil:water) mouthwashes. Essential oils have been found effective in reducing halitosis, and are being used in several commercial mouthwashes.

Maintaining proper oral hygiene, including daily tongue cleaning, brushing, flossing, and periodic visits to dentists and hygienists. Flossing is particularly important in removing rotting food debris and bacterial plaque from between the teeth, especially at the gumline. Dentures should be properly cleaned and soaked overnight in antibacterial solution (unless otherwise advised by your dentist).


  1. Probiotic treatments, specifically Streptococcus salivarius K12 has been claimed to suppress malodorous bacteria growth, however well designed randomised control clinical trails are needed to assess this. Certainly there is more evidence for mechanical tongue cleansing and to a lesser extent specific antimicrobial mouthwashes.