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Bad breath (halitosis, fetor oris, or fetor ex ore)                                   REF: UpToDate 2006  

 Causes  |  Dx  |  Rx  
Bad Breath (Halitosis) is defined as any detectable offensive smell carried on the breath.  Gases that might appear in the breath in abnormal concentrations, yet are not detected by the nose, would not fall under this definition.

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 preliminary report of a study that measured oral malodor in 88 adults in the morning (before breakfast, brushing, etc.) concluded that 20 to 40 percent of adults suffer from morning breath.

Many millions of people worry about having bad breath at one time or another. In a survey of 1200 Canadians, as an example, 17 percent admitted to being very worried about having bad breath.

Around 20 percent of the adult population worry about bad breath when little or none is measured, and approximately 25 to 30 percent of individuals seeking professional counsel for complaints of bad breath are halitophobics.


 Causes  |  Dx  |  Rx  
CAUSES of Bad Breath (Halitosis):

ETIOLOGY AND PATHOGENESIS — Bad breath may originate from the following sources:

  1. The oral cavity (85-90% of ambulatory patients)
    - Oral pathology such as gingivitis and periodontitis may also contribute to bad breath, although individuals without such disorders also experience oral malodor.
    - comes primarily from bacterial accumulation between the teeth, and from the posterior part of the tongue dorsum (perhaps due to accumulation and subsequent putrefaction of postnasal drip on the back of the tongue)

    - Volatile sulfur compounds (VSCs), primarily hydrogen sulfide and methylmercaptan, are partly responsible. VSCs arise presumably via microbial degradation of methionine and cysteine. Other gases that are by-products of amino acid degradation and may be implicated in the pathogenesis of bad breath include indole and skatole (via breakdown of tryptophan) and cadaverine (via breakdown of lysine).
    -Gram negative anaerobic proteolytic bacteria are the primary microbes implicated in producing VSCs and therefore causing bad breath. Pathogens involved include Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, and spirochetes.
    -Gram positive microorganisms may also be involved in the initial stages of malodor production by deglycosylating the glycoproteins that are subsequently broken down by the proteolytic enzymes secreted by the Gram negative bacteria.
  2. Nasal passages (about 5 to 8 percent)
    -Nasal odor may be indicative of a frank nasal infection (such as sinusitis), or a problem affecting airflow or mucous secretions (eg, polyps). In some cases, craniofacial anomalies, such as cleft palate, may be involved. It is not uncommon for patients with no obvious pathology to suffer from nasal malodor.

  3. Tonsils (perhaps 3 percent)
    - Tonsillectomy based solely upon a complaint of bad breath should be avoided.
    - Some patients complain of small stones on their tongue or tonsils when they cough that have a foul odor. These stones are "tonsilloliths" that form in crypts of the tonsils. They are relatively common, occurring in perhaps 7 % of the population at one time or another. Although the stones have a foul smell, they do not always cause bad breath. However they do lead patients who have them to infer that their breath is extremely fetid. The appearance of tonsilloliths can be prevented by lasing the crypts in which they form (laser cryptolysis, still an uncommon practice).

  4. A variety of other causes
    - including bronchial and lung infections, kidney failure, liver failure, various carcinomas, metabolic dysfunction (as ketone/acetone breath from diabetes ketoacidosis, and biochemical disorders, but these are very rare in the ambulatory population and are usually accompanied by more obvious symptoms.
    - Bad breath almost never arises from the esophagus, stomach, or intestines. The esophagus is normally collapsed and closed; an occasional belch may carry odor up from the stomach, but the possibility of air escaping continuously is remote. Thus, gastroscopy should never be performed solely for the complaint of bad breath in an otherwise healthy ambulatory patient.
    - Trimethylaminuria may be suspected in patients complaining about a fishy type odor. This rare genetic condition involves the inability to breakdown N-oxidise trimethylamine. As a result, malodorous trimethylamine builds up in sweat, saliva, and urine. Malodor can be reduced by managing the diet to reduce the ingestion of precursors of trimethylamine such as carnitine and particularly choline.
    - Patients who suffer from xerostomia do not appear to have excessive malodor despite the mouth dryness . The reason for this is unknown, although it may be due to a low oral pH and its effects upon the oral flora.

In addition to the causes listed above, bad breath can be exacerbated by:

  • Accumulation of postnasal drip on the posterior of the tongue dorsum (in children and adults)
  • Poor oral hygiene (particularly failure to clean between the teeth with floss or an anatomical tooth pick)
  • Improper dental care (eg, faulty bridgework, leaking crowns, abscesses)
  • Mouth breathing and other causes of dry mouth (eg, fasting, medication, stress, prolonged speech, long time between meals)
  • Unclean dentures (eg, left in mouth unnecessarily during the night)
  • Onions and garlic
    - one gas, allyl methyl sulfide, was exhaled for prolonged periods of time after garlic ingestion as a result of gastrointestinal absorption, systemic circulation, and ultimately excretion through the lungs.
  • Alcohol
  • Menstrual cycle
  • Proteinaceous foods that get stuck between the teeth


 Causes  |  Dx  |  Rx  

For this reason, such patients should bring along a confidant to the appointment; that is, an adult close to him or her, usually a family member or close friend. The confidant can confirm the existence of a breath problem, compare the intensity and quality of the odor at the appointment with the patient's usual odor and subsequently provide feedback on improvement (or lack thereof) following the consultation.

History — The evaluation begins by taking a good medical history. Concentrate on trying to find out whether the patient practices good oral hygiene, has full or partial dentures, is a mouth breather, snores, suffers from hay fever, has any nasal obstruction (or history of nasal problems), or any other underlying medical problem that may be involved. Ask both the patient and the confidant where they think the odor is coming from and why.

"Nobody has actually told me I have bad breath, but I know because people cover their mouths when they talk to me, people open windows in my presence, people touch their nose when talking to me, I have a bad taste in my mouth, my father had it, someone told me when I was in fourth grade." These types of answers are typical of halitophobics who have a grossly exaggerated fear of having bad breath. Halitophobics are often women, impeccably groomed, and commonly break down in tears during the patient history. Many of these patients need psychological input but often resist it, convinced that their problem is organic. Many halitophobics have read the scientific literature on bad breath, and frequently brush their teeth and tongue, frequently floss and gargle, and have no observable bad breath. They may misinterpret having a bad taste or the presence of tonsilloliths as evidence their breath is horrid. It should always be kept in mind, however, that some halitophobics do suffer from bad breath.

Physical examination — Several companies are working on the development of electronic noses that can analyze bad breath, but no instrument is currently able to replace the human nose. Current instruments measure the reduce sulfur component of malodor. The results are associated with malodor levels, but cannot be relied upon as stand-alone measurements. Several colorimetric enzymatic tests have the same limitation. Thus, clinicians interested in diagnosing bad breath must still rely upon their noses to distinguish the main types of oral odors:

  • Periodontal-type odor, which usually comes from periodontal pockets and interdental spaces
  • Odor from the posterior tongue dorsum, which can easily be determined using the "spoon test"
  • Denture odor (readily smelled by placing the dentures into a plastic bag for several minutes)
  • Nasal odor (easily identified on the breath exiting the nose)
  • Smoker's breath
  • With practice and experience these odors become distinct and recognizable, even when found in various combinations.

Ask the patient to breathe out through the mouth. Smell the odor from about 5 to 10 cm and make a quantitative (eg, on a zero to five scale where zero is no odor; one is barely detectable odor; two is slight odor; three is moderate odor; four is foul odor; and five is unbearably foul odor) and a qualitative (eg, typical/not typical; periodontal/tongue) judgment. In addition, it may be helpful to ask the patient to count out loud to twenty and repeat the above. This is because the odor is sometimes more obvious when the patient is speaking.

After evaluating mouth odor, check the nasal odor by asking the patient to close his or her mouth and breathe out through the nose. Score as above. An oral or pharyngeal origin is suspected if the odor is largely confined to the mouth and not the nose; nasal involvement is suspected if the odor is largely confined to the nose or has a telltale characteristic odor. A systemic origin is suspected in the rare cases in which the odor emanates both from the mouth and nose and has the same quality.

The tongue odor can be evaluated by taking a plastic spoon in one hand, a piece of gauze in the other, and asking the patient to stick out the tongue as far as possible and to hold his or her breath. Wrap the gauze around the tip of the tongue and hold it with one hand, use the spoon with the other hand to scoop up some of the mucus at the very back of the tongue dorsum towards the throat (about 12 cm from the tip of the adult tongue). Wait a few seconds. Smell and score the spoon. Ask the confidant to smell the spoon and answer whether this is the quality of the odor the patient suffers from (if so, tongue cleaning and gargling should handle the problem). In many cases a yellowish discharge is collected on the spoon; although there is no direct evidence, this discharge is probably postnasal drip. The center of the tongue dorsum may produce malodor in patients with hairy coated tongues.

Postnasal drip is extremely common and is usually not indicative of any frank nasal infection or other pathology. Although the postnasal drip might not smell initially when it first reaches the tongue, it can subsequently be putrefied by the abundant tongue microbiota. In subjects with periodontal disease, the tongue may be even more malodorous.

An oral source can be confirmed by instructing the patient to rinse and gargle twice daily, including once at bedtime; gargling is more important than rinsing. A mouthrinse such as chlorhexidine mouthrinse should be used. Rinsing and gargling should continue for one week, but not longer. Advise the patient to discontinue the mouthrinse immediately if ulceration or other discomfort arises. Ulceration occurs in about 5 percent of patients, perhaps more in Asian populations.

Removable full or partial dentures should be taken from the mouth and smelled separately. They can be cleaned by ultrasonic bath if they smell foul. If this is not helpful, they may need replacement. Encourage patients to leave them overnight in an appropriate disinfectant unless there is a medical reason to leave them in the mouth.

Patients should not automatically be labeled halitophobic if no odor is discovered. Test the breath again on another occasion and try to get confirmation that there is an odor from a confidant and family members. If the presence of an objective odor still cannot be confirmed, the patient may be advised to consult a psychologist or psychiatrist although, as previously mentioned, many halitophobics are convinced that they have an actual odor and that there is no psychological basis whatsoever for their complaint. In such instances, it is very difficult to persuade them to seek psychological counsel, and the physician must try to allay their concerns.

Sulfide monitors — The level of intraoral VSC can be estimated using portable sulfide monitors. Sulfide monitor readings are sensitive to reductions in mouth odor levels following the use of mouthrinses. The association between sulfide monitor results and odor judge scores is significant (coefficient correlations ranging from about 0.45 to 0.65, p <0.001 in various studies) and relatively reproducible. Nevertheless, while such quantitative and semiquantitative measurements can be helpful (eg, to apprise the patient of the improvement which has taken place), they do not obviate the need for the clinician to actually smell the breath emanating from the mouth, nose, and tongue of the patient.


 Causes  |  Dx  |  Rx  

Patients with an identifiable cause of bad breath (eg, periodontal disease, gingivitis, postnasal drip, systemic illness) can be treated for these conditions.

In addition, an oral source of bad breath may be alleviated by:

  • Proper dental care and oral hygiene.
    - Encourage patients to floss their teeth (properly), to smell the floss between each passage, and to clean the malodorous sites carefully. Flossing should include cleaning the posterior surface of the back teeth as well.
  • Gentle cleaning of the posterior portion of the tongue dorsum (eg, with a plastic tongue cleaner). It is important to impress upon the patient the importance of gentle cleaning rather than outright "scraping", which may traumatize the tongue.
  • Rinsing and deep gargling with an effective mouthwash (in order to get the liquid as far back as possible without swallowing it, one can extend the tongue while gargling).
  • Eating fibrous foods (a healthy breakfast can be recommended).
  • Brief gum chewing (five minutes is often sufficient) if the mouth is dry.
  • Sufficient liquid intake.
  • Some physicians prescribe antibiotics for complaints of bad breath. However, this only results in transient relief and, in my opinion, is not advisable.

Patient referral
Dentists often become involved in the evaluation of bad breath since most cases can be traced to problems with the tongue, teeth, and periodontum. In addition, oral hygiene, an important component of bad breath therapy in many patients, is typically taught by dentists and hygienists.

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