Do you have bad breath?

How is your breath, not sure? No doubt at some point each of us has unwittingly had bad breath (halitosis) only to subsequently be embarrassed by the reactions of those around us.

For any individual the exact status of one's breath can be difficult to ascertain. The reason for this lies in the fact that the oral cavity, the source of our breath, is connected to our nose by way of an opening which lies in the back of our mouth (back in the region of our soft palate). Since noses tend to filter out and ignore background odors, it filters out and ignores our own bad breath. This means it is quite possible for a person to have bad breath, yet not be aware of it.

So, how can you tell if you have bad breath?

If our own noses can't reliably help us judge the quality of our own breath, how can we determine if we do have bad breath? One solution is to ask the opinion of a spouse or significant other. In lieu of the availability of these individuals you might ask a friend or else your dentist or hygienist at your next dental appointment. If you find this type of question too personal to ask an adult don't overlook asking a child. As we all know, sometimes the least inhibited and most honest responses come from children.

Is there a way a person can test his own breath?

There are ways to accurately smell your own breath, however you have to take a slightly indirect route.

Try this technique. Lick your wrist, wait about five seconds while the saliva dries somewhat, and then smell it. What do you think? That's the way you smell. Or, more precisely, that's the way the end of your tongue smells (your tongue's "anterior" portion). How was it? Did you pass this first check?

Now do this experiment, it will check the odor associated with the back of your tongue (your tongue's "posterior" aspect).

Take a spoon, turn it upside down, and use it to scrape the very back portion of your tongue. (Don't be surprised if you find you have an active gag reflex.) Take a look at the material that has been scrapped off, usually its a thick whitish material. Now, take a whiff of it. Not so bad? Pretty nasty? This smell, as opposed to the sampling from the anterior portion of your tongue, is probably the way your breath smells to others.

The fundamental cause of bad breath is...

So now you know, the fundamental cause of bad breath for most people is the whitish coating that covers the surface of the posterior portion of their tongue. More accurately, bad breath is caused by the bacteria that live in this coating. (The second most common fundamental cause of bad breath is bacteria that live and accumulate elsewhere in a person's mouth.)

The remainder of the text on this page describes various methods by which dental researchers attempt to quantify levels of bad breath. If you're interested in this topic of course please read on, otherwise you may want to skip on to our next page of topic bad breath.

How academic researchers test for bad breath.

Before a dental researcher can evaluate various cures for bad breath they must first have a way to measure its severity, both initially and after the cure they are studying has been administered. Some of the different methods researchers have used to measure bad breath are discussed below.

Organoleptic judging of bad breath.

Judging of a person's bad breath by way of organoleptic testing simply means that the one performing the breath evaluation has used their sense of smell (their nose) as the means for making the determination. Historically this method of breath testing has been a frequent choice among dental researchers. Noses are readily available, inexpensive to obtain and operate, and to their credit noses can detect up to 10,000 different smells.

The problem one encounters with organoleptic testing is that it does not provide an evaluation of bad breath that is totally objective. Factors other than breath odors can and do influence organoleptic evaluations. In fact research has shown that factors such as hunger, menstrual cycle, head position, and the degree of attentiveness and expectation can each influence a judge's interpretation of what they smell.

As for quantifying the organoleptic measurement itself, what exactly does constitute a weak, strong, or average level of bad breath? Will each judge involved in the research be able to make equivalent comparisons? Complicating things even more, as we all know when we are repeatedly exposed to a bad odor our sense of smell acclimatizes to the odor and therefore our sense of smell loses much of its sensitivity. Bad breath that seems exceedingly objectionable at the beginning of testing may seem quite less so as the evaluation continues.

Using gas chromatography to evaluate bad breath.

Researchers in a number of scientific fields have long used gas chromatographs as a means of identifying the gases found in the samples they are studying. Likewise, gas chromatographs have been utilized by dentists in bad breath studies and have provided a means by which a researcher could definitively quantify the precise levels of specific compounds present in someone's breath.

While gas chromatography is probably the best way to test for the compounds associated with bad breath it has not been widely utilized in studies for several reasons. Gas chromatographs are relatively expensive and need personnel with special training to operate them. The equipment is not portable and a significant amount of time is needed to make each breath measurement.

Using Halimeters to judge bad breath.

A specialized type of sulfide monitor (termed a Halimeter) has been developed and it provides a means by which a tester can quantify degrees of bad breath. These machines, first introduced in 1991, measure the amount of sulfide gasses found in a person's breath. Some sulfides, such as hydrogen sulfide and methyl mercaptan (collectively referred to in dental literature as volatile sulfur compounds or "VSC's"), are well known as being causative agents for bad breath. A Halimeter's discovery of a high level of sulfides suggests a correlating high level of VSC's, although the individual types of VSC's aren't tested for specifically.

Since Halimeters test for a fewer number of compounds than gas chromatographs (sulfides only), and in fact test for no individual compounds at all but instead just sulfides as a class, Halimeters provide for a less definitive evaluation of a person's bad breath than gas chromatographs can. Additionally, compounds such as ethanol (alcohol) and essential oils (both being compounds commonly found in mouthwashes) interfere with a Halimeter's ability to make a measurement. The advantages of using a Halimeter for a study rather than a gas chromatograph are that a Halimeter requires no special training to use, is portable, breath measurements can be made quickly, and the apparatus itself is comparatively inexpensive.


The BANA test.

Some of the bacteria that cause periodontal disease (gum disease) produce waste products that are quite odiferous and as a result contribute to the presence of bad breath. Some of these types of bacteria can be tested for by way of a BANA test.

The bacteria in question have the characteristic of being able to produce an enzyme that degrades the compound benzoyl-D, L-arginine-naphthylamide (abbreviated BANA). When a sample containing these bacteria is placed with the BANA compound they break it down and the result is a compound that has a different color.


Utilizing chemiluminescence in detecting bad breath.

One of the more recently developed methods of testing for the presence of compounds associated with bad breath relies on the principle of chemiluminescence. This type of testing was first introduced in 1999. When a sample containing sulfur compounds (such as VSC's, the types of compounds which cause bad breath) is mixed in with the test's mercury compound the resulting reaction causes fluorescence. The strength of this methodology is that it can provide better selectivity and sensitivity when measuring low levels of sulfur compounds, as compared to testing with a Halimeter.