Author: elena carrara
Date: 24/06/2009



Halitosis (bad breath) is an oral health condition characterized by consistently odorous and unpleasant breath.

The disease database


There are no reliable estimates of prevalence, although several studies report the population prevalence of halitosis (physiological or because of underlying disease) to be about 50%.
Epidemiological studies suggest that:

  • 24% of the Japanese population have oral malodour
  • 25% of European, American and Japanese populations have perceivable oral malodour and 6% have permanent oral malodour

Bad breath has been with us for thousands of years. The problem is discussed at length in the Jewish Talmud, as well as by Greek and Roman writers. Ancient folk remedies abound that are still in use. The book of Genesis (Chapter 37) mentions ladanum (mastic), a resin derived from the Pistacia lentiscus tree, which has been used in Mediterranean countries for breath freshening for thousands of years. Other folk cures include parsley (Italy), cloves (Iraq), guava peels (Thailand), and eggshells (China).


A few of the common signs of this disease are:

  • a white coating on the surface of the tongue: in some people, a 'coating' develops on the back part of the tongue. It is not clear why this occurs. It may be from mucus that drips down from the back of the nose ('post nasal drip'). The coating can contain many bacteria. This explains why bad breath can sometimes occur in people with otherwise good oral hygiene.

  • a sour, bitter, or metallic taste related to higher acid levels in the mouth
  • dryness in the mouth, extreme morning breath, or evidence of thicker saliva
  • high levels of postnasal drip or mucous in the throat

  • an increase in bad breath, after eating certain foods, using mouthwashers or otherhormonal therapies (estrogen, progesterone,etc.), or during the menstrual cycle.


There are three main methods of quantifying oral malodour: organoleptic measurement, gas chromatography (GC), and sulphide monitoring.

  • Organoleptic measurement. A subjective test scored on the basis of the examiner's perception of a subject's oral malodour. Different semi-quantitative scales have been used, however, at the most recent International Workshop on Oral Halitosis (1999), there was consensus on using a scale ranging from 0 to 5.
    Before the organoleptic assessment, both patients and examiner must follow some instructions in order to obtain a more reliable result. Patients are instructed to abstain from eating strong foods at least 48 hours before the assessment and to avoid using scented cosmetics for 24 hours before the assessment. Patients must abstain from ingesting any food or drink, omit their usual oral hygiene practices, abstain from using oral rinse and breath fresheners, and abstain from smoking for 12 hours before the assessment. The oral malodour examiner is required to refrain from drinking coffee, tea, or juice and to refrain from smoking and using scented cosmetics before the assessment.
  • Gas chromatography (GC). GC is considered the gold standard for measuring oral malodour since it is specific for VSCs, the main cause of oral malodour. The GC equipment is expensive, bulky, and the procedure requires a skillful operator. Therefore, this technology has been confined to research and not to clinical use.
  • Sulphide monitoring. Sulphide monitors analyse for total sulphur content of the subject's mouth air. Although compact sulphide monitors are inexpensive, portable, and easy to use, most of them are not able to distinguish among the VSCs. For example, the Halimeter, one of these monitors, has high sensitivity for hydrogen sulphide but low sensitivity for methyl mercaptan which is a significant contributor to halitosis caused by periodontal disease.


The responsables of bad breath are volatile sulfur compound. VSC are produced throught various bacterial metabolic way in the mouth. These are reductive reactions of solphates and cathabolism of sulfurated amminoacids as methionine and cysteine which derives from the proteolytic activity of oral microflora. From the degradation of these amminoacids results the production of hydrogen sulphide and methyl mercaptan.
There is evidence that production and volatilization of VSC decrease in case of fall in oral pH, rise in oxygen level and presence of fermentable glicids.

While volatile sulfur compounds are the principle causative agents of bad breath, the bacteria which live in the mouth also produce other waste products and some of these have their own unpleasant odors too. A few of these wastes are:


  • PUTRESCINE - which is responsible for much of the odor of decaying meat
  • SKATOLE - the characteristic smell of human fecal matter
  • ISOVALERIC ACID -the smell of sweaty feet

Controversy on the role of helicobacter pylori

According to some studies Helicobacter Pylori would have got a determinant role in the arising of halitosis. Eradication of H. pylori in patients with functional dyspepsia and halitosis results in sustained resolution of halitosis during long-term follow-up in the majority of cases.
This association may be realistic because helicobacter pylori causes gastric ulcer and is known that gastric ulcer provokes bad breath.

Bacteria involved

Bad breath is causing by bacteria, which are anaerobic (more specifically Gram-negative anaerobic bacteria) and these produce sulfur. These bacteria such as Veillonella , Fusobacterium nucleatum, and Porphyromonas gingivalis love living within the surface of the tongue and in the throat. These bacteria are supposed to be there because they assist humans in digestion by breakingdown proteins found in specific foods, mucous, blood or "broken-down" oral tissue.

A human mouth can be home for hundreds of different species of bacteria. There are bad bacteria which produce maleodorant VSC and good bacteria which are unable to sythetise them. And it is the precise balance between the relative numbers of these two different types of bacteria that will ultimately determine the quality of a person's breath.

Dental plaque accumulation (the whitish film that forms on teeth both above and below the gum line and also on the tongue) can tip the scales in favor of the odor causing bacteria. It is surprising to learn that a layer of plaque as thin as 0.1 to 0.2 millimeters (about the same thickness as a dollar bill) can be oxygen depleted, thus creating the precise type of environment in which anaerobic bacteria will flourish.

So, as more and more plaque builds up in a person's mouth the bacteria that cause bad breath gain available living space and proliferate, thus increasing the level of odor causing compounds that escape with each breath that is exhaled.


The risk of halitosis increases in patient with mouth problems in 80% of cases. Other medical causes are very rare. All these factors are acquired.

Morning bad breath

Most people have some degree of bad breath after a night's sleep. This is normal and occurs because the mouth tends to get dry and stagnate overnight. This usually clears when the flow of saliva increases soon after starting to eat breakfast. Saliva naturally contains oxygen, which keeps the mouths healthy and fresh. If there is less saliva, there's less oxygen, thereby creating an anaerobic environment, perfect for bacteria to produce odourous and bitter compounds.
There are several common causes of xerostomia that will ultimately cause halitosis, including:

  • Excessive Speaking
  • Recent Change In Exercise/Diet Routine
  • Prescription Medication Side Effect
  • Alcohol Consumption
  • Smoking Tobacco Products
  • Caffeine Consumption

Foods, drinks and medicines

Chemicals in foods can get into the bloodstream, and then be breathed out from the lungs. Most people are familiar with the smell of garlic, spicy foods and alcoholic drinks on the breath of people who have recently eaten or drunk these. Various other foods and medicines can cause a smell on the breath. This type of bad breath is temporary and easily cured by not eating the food.
Generally high protein foods are involved in halitosis, because bacteria love proteins and certain foods are packed with them:

  • milk and cheese and most other dairy products
  • fish
  • coffee with caffeine (and even without)

Medicines that have been associated with bad breath include: betel, chloral hydrate, nitrites and nitrates, dimethyl sulphoxide, disulphiram, some chemotherapy drugs, phenothiazines and amfetamines.


Most non-smokers can tell if a person is a smoker by their breath which 'smells like an ashtray'. Stopping smoking is the only cure for this type of bad breath. Smoking also increases the risk of developing gum disease, another cause of bad breath.

Crash dieting or fasting

Can cause a 'sickly sweet smell' on the breath. This is due to chemicals called ketones being made by the breakdown of fat. Some ketones are then breathed out with each breath.



Some people with nose problems can get bad breath. For example, a polyp in the nose, sinusitis or a 'foreign body' stuck in a nostril (occurs most commonly in children) can cause a bad smell. In this situation the smell tends to occur only, or more severely, when you breathe out through your nose. It is not so noticeable when you breathe out through your mouth. Infections or tumours of the lung, throat, mouth or tonsils are sometimes a cause. Problems with the renal system leading to uremia cause the breath to have a urine smell, while gall bladder problems and liver disorders like chirrosis give the breath a mousy odour. Leukemia and other blood disorders have associated effects as well. Other causes are rare.
Only 1% of the causes are from gastrointestinal upset such as gastro-esophageal reflux disease due to a weakening of muscles that line the esophagus.

Food stuck between teeth. Normal teeth brushing may not clear bits of food which can get stuck between teeth. The food then rots and becomes riddled with bacteria. Regular flossing can clear and prevent this problem.
Plaque, calculus and gum disease. Dental plaque is a soft whitish deposit that forms on the surface of teeth. It forms when bacteria combine with food and saliva. Plaque contains many types of bacteria. Calculus, sometimes called tartar, is hardened calcified plaque. It sticks firmly to teeth. Gum disease means infection or inflammation of the tissues that surround the teeth. The severity can range form mild to severe.
Chronic halitosis, however, is generally not the result of rotting or putrefying food particles within the mouth. In most instances, the bad breath is the result of some infection raging within the oral cavity. Where oral infections are concerned, there are three primary sources to investigate:

In all three cases, bacteria is once again the true source of both the decay and the odor associated with halitosis. Their levels progressively increase with severity of periodontal involvement and deepending of periodontal pockets. The production of large amounts of thiol compounds at periodontal diseased sites has ominous implications. They have the potential to exert very destructive effects on oral mucosal tissues, especially the connective one. Of particular significance is their suppression of collagen synthesis and an increase in collagen degradation. In addition they stimulate select cytokine production in culture systems indicatingthat they can activate the immuneresponse system, thereby causingan increase in production and activation of collagenolytic enzymes. At the end results that in addition to bacteria, VSC production and the elevated methyl mercaptan production might accelerate the periodontal disease.
Unless the source of the infection is either removed or treated so that the bacteria are eliminated, no permanent halitosis cure is possible. Even when the teeth and gum tissue are rid of bacteria and infection, there is still the tongue to consider as a potential source of bad breath/halitosis problems. Especially towards the back of the tongue, bacteria tend to hide beneath a semi-permanent layer of mucous. The enzymes present in saliva normally kill off harmful bacteria in the mouth-but neither saliva nor the beneficial enzymes can get to the bacteria so they continue to cause halitosis problems until they are removed via brushing.


Controlling the mouth bacteria that produce VSCs is the key to tackling halitosis.

Regular dental care is paramount to controlling bad breath, as halitosis will never disappear in the presence of periodontitis or tooth decay.

Brushing Properly- Proper tooth brushing involves not only removing the plaque from all tooth surfaces, but also gently cleaning below the gum line as well. Many newer toothbrushes are designed to do this, but most patients have neither the dexterity nor the patience to perform the dental gymnastics required. Electric brushes are a simple and effective solution. These gismos are far superior at plaque removal in the hands of most people, particularly below the gum line where VSC producing bacteria hide and thrive.

Flossing Properly and DAILY! - Halitosis will never go away without daily flossing. It also must be done effectively, getting below the gum line and removing the plaque hiding there. The gum pockets between the teeth are the second largest reservoir of VSC producing bacteria, after the tongue.

Tongue Cleaning - Simply brushing the tongue is not enough. Tongue must be clean with a proper tongue-cleaning device, using specific tongue cleaners.

These instruments are designed to scrape the plaque from the tongue instead of brushing. In addition they remove the outermost layers of dead skin. This tissue contributes to bad breath both through its own breakdown and that it makes a great environment for the VSC producing bacteria. It is also important to clean as far back on the tongue as possible. This is achieved by sticking the tongue out as far as possible while scraping.

Mouthwash- A good antibacterial mouthwash after the above hygiene practices helps kill the remaining VSC producing bacteria and slows their regrowth. Listerine and generic equivalents are perfect for this. The mouthwash should remain in the mouth for a minute if possible, thoroughly swishing between the teeth, over the tongue, and a bit of a gargle in the throat. Some newer formula mouthwashes claim to be able to breakdown VSCs and may also be helpful.

Natural remedies against halitosis

Home remedies for bad breath include such things as mixing baking soda with hydrogen peroxide for a homemade mouthwash, chewing on sprigs of fresh mint or whole cloves, brushing with baking soda, and even chewing sunflower seeds.
Among the several home remedies for halitosis, the use of fenugreek has proved most effective. A tea made from the seeds of this vegetable should be taken regularly for correcting the condition. Another effective remedy for bad breath is avocado, which is far superior to any mouth lotion or remedies for this condition. It effectively removes intestinal putrefaction or decomposition which is one of the most important causes of bad breath. Unripe guava is useful in halitosis. It is rich in tannic, malic, oxalic, and phosphoric acids as well as calcium, oxalate, and manganese. Chewing it is an excellent tonic for the teeth and gums. It helps cure bleeding from gums and stops bad breath. Chewing tender leaves of guava tree also stops bleeding from gums and bad breath.
Cardamoms can be used as a mouth freshner and helps in treating halitosis. Chew cardamom after meals and in between the long intervals. This would surely cure a person from bad breath.
All fruit and vegetable juices are beneficial in the treatment of halitosis and should be taken liberally by those suffering from this disorder. Juices from green vegetables are especially valuable. Choose a mouth wash which contains eucalyptol and thymol. Derived from eucalyptus and thyme respectively, these proved worthwhile in destroying bad breath.

2010-05-24T19:58:24 - Elena Manzon

Halitosis with a typical smell of fruit (ketonic smell) is one of the first signals of the possible presence of diabetes. Another important signal is the smell of the VSC that indicate the presence of tongue's coat and/or periodontal disease. oral manifestation

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