Halitosis and the kissability factor

July 1, 1999
Fact one: "Kissability," according to General Bernier of the United States Army Dental Corps, is a better motivator among Army personnel than good oral health. Fact two: Bad breath is a billion-dollar industry in this country. Keep these facts in mind.

`Kissability` is a better motivator among Army personnel than good oral health!

Trisha E. O`Hehir, RDH, BS

Fact one: "Kissability," according to General Bernier of the United States Army Dental Corps, is a better motivator among Army personnel than good oral health. Fact two: Bad breath is a billion-dollar industry in this country. Keep these facts in mind.

What is "bad breath?" Professor Tonzetich defined halitosis as "...unpleasant breath arising from physiological and pathological causes from oral and systemic sources." Since the 1930s, halitosis estimates have ranged from 47-90 percent, depending on the time of day and foods eaten. Halitosis is the result of cell breakdown, including bacterial cells, epithelial cells, especially on the tongue; and remaining food particles found between the teeth. This breakdown occurs within the saliva, with increased flow reducing odors and decreased flow leading to more odors.

Salivary putrefaction occurs (especially during sleep) when saliva flow is essentially zero. In laboratory tests, incubation of saliva resulted in objectionable odors at one hour. At the end of three hours, the odor often is too intense for accurate measurement. Saliva from patients with periodontal disease putrefies more rapidly and is more objectionable. This is due to a greater number of disintegrated epithelial cells, bacteria, and damaged leukocytes. An acid pH in saliva is not conducive to malodor production. A pH rate of about 6.7 leads to malodor. Surprisingly, when sugar is added, the pH falls and odor production is reduced. Blood provides essential substrates for odor production, accumulating in the saliva, on the tongue, and becoming trapped within bacterial plaque.

During putrefaction, a shift occurs from gram-positive to gram-negative organisms. These microorganisms putrefy sulfur-containing proteins releasing volatile sulfur compounds. The compounds primarily responsible for oral malodor are hydrogen sulfide and methyl mercaptan, with methyl mercaptan being the worst. It is detected at lower levels, but is more offensive than hydrogen sulfide. These two sulfur-containing compounds account for 90 percent of the sulfur content in the mouth, with 60 percent of the compounds found on the dorsum of the tongue. Hydrogen sulfide is associated with the tongue and methyl mercaptan is associated with periodontal pockets. Tongue-coating is heavier in periodontal patients and is made up of epithelial cells released from the oral mucosa and microorganisms and leukocytes from periodontal pockets.

The turnover rate of junctional and sulcular epithelial cells in a healthy mouth is two to four days. The rate increases eight-fold in a diseased mouth, which means replacement of epithelium could take place in only six hours. Breakdown of epithelial cells at this rate leads to volatile sulfur-compound levels that are both clinically and socially significant. Breakdown of the amino acid, methionine, results in the release of methyl mercaptan. Increased gingival crevicular-fluid flow in periodontal infection results in higher levels of methionine, leading to more methyl mercaptan release.

The bacteria and epithelial breakdown associated with periodontal disease have been shown to increase oral malodor, but the influence also may go the other way. The permeability of mucosa was increased when volatile sulfur compounds were added to the control atmosphere. Therefore, the volatile sulfur compounds of bad breath are not only a result of disease, but seem to contribute to the progression of disease. They do this by increasing permeability of the crevicular-epithelial barrier and allowing bacterial by-products to pass through to underlying tissues. Volatile sulfur compounds also slow tissue-healing by interfering with protein synthesis and collagen maturation in gingival fibroblasts.

About 10 percent of halitosis is attributed to non-oral sources. Chronic sinusitis associated with postnasal drip, tonsillar conditions, malignant neoplasms, and foreign bodies within the nasal cavity have been implicated. Very little evidence exists to connect stomach or intestinal problems with halitosis, since the esophagus is normally a collapsed tube, cutting off connection to the stomach. However, odor will escape, from the stomach during belching.

Certain drugs also can cause mouth odor. These drugs include psychotropic drugs, cytotoxic drugs, Antabuse, and some angina drugs. Drugs causing xerostomia contribute indirectly to halitosis.


Halitosis studies use human judges to smell mouth odor (organoleptic measurements), as well as gas chromatography that mechanically measures sulfide concentrations in the mouth, spoon-scrapings of the tongue, wrist-licking, or dental floss between the teeth. There is a more objective test - gas chromatography - but it is relatively expensive and requires special equipment and time. These sulfide monitors have been adapted for clinical use, but do not always correlate with organoleptic measurements. A Belgium study demonstrated significant improvement in organoleptic scores, but no change was noted in sulfide levels. Perhaps this was due to a reduction in methyl mercaptans that were not detected by the sulfide monitor, but which smell worse than sulfides. On the other hand, some studies have shown a good correlation between sulfide monitors and odor judges. Depending on the case, sulfide monitors may or may not be a reliable measure of oral malodor.

The problem with human measurement of mouth odor is the variation between odor judges. Men and women have different smell acuity, and judges also may have their own oral malodor, complicating things. An ideal system for measuring oral malodor has yet to be identified.

Treatments for halitosis include removal of local factors, oral hygiene instruction, focusing on interproximal areas and plaque removal from the tongue, and chewing of sugarless gum to stimulate salivary flow. If a systemic cause for halitosis is suspected, a medical referral should be made. Patients with no detectable bad breath, but who believe they have halitosis, are the most difficult to treat. Psychiatric counseling is needed, but not generally accepted by these patients.

Although the focus of mouthrinse research has been the reduction of bacterial plaque and gingivitis, the common reason for mouthrinse use by the general public is bad breath. However, very little research has been published providing evidence of the efficacy of mouthrinses for control of oral malodor. Several clinical trials have found regular use of zinc oral rinses (BreathRx and others) is effective in reducing volatile sulfur compounds by 50 percent. One recently published paper found a single, 30-second rinse with CloSYSII?, which contains an 0.1% stabilized chlorine-dioxide formulation, controlled bad breath for up to eight hours.

Since the tongue is the primary source of these volatile sulphur compounds, both professional and daily cleaning should be stressed. Daily tongue-cleaning can be done with a regular toothbrush, a special low-profile tongue brush, various scrapers, a spoon, or a soft washcloth. Whatever is used, care should be taken to avoid injuring the surface of the tongue. Interproximal cleaning also is essential, because trapped bacteria and food particles contribute significantly to bad breath. If a rinse is used, it should be alcohol-free or very low in alcohol content. It also should contain ingredients that control these compounds, rather than simply masking the odor.

Professional tongue-cleaning can be accomplished with a variety of brushes and tongue-scrapers or with a modified Prophy Jet?, using chlorine dioxide rather than sodium bicarbonate. The Prophy Jet working tip is modified by adding a spray deflector, thus preventing gagging.

At the beginning of this article, I made some points about OkissabilityO and the billions being spent for bad-breath products. Despite a lack of scientific evidence about bad-breath products, people keep buying them. They aren?t especially interested in preventing caries and periodontal disease, but they sure do want to be Okissable.O It?s up to us to provide as much information and advice on the subject as possible. After all, if hygienists can?t talk to people about bad breath, who can?

Patients don?t want bad breath and will do whatever it takes to get rid of it ? even to cleaning their tongues and removing plaque from between their teeth! Of course, these efforts also will prevent caries and periodontal disease; but, we don?t need to mention that right now. They?ve already heard about gum disease, so why not use the subject of halitosis to get their attention?

Trisha E. O`Hehir, RDH, BS, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics. The Web site for Perio Reports is www.perioreports.com. Her e-mail address is trisha@perioreports. com.