Most of the time, when someone around you has bad breath, you become aware of it fairly quickly. The amount of airborne volatile sulfur compounds (VSCs) needed to alert your nose to halitosis if fairly small. What about the amount of VSCs needed to classify bad breath in the lab?
It can vary. So can bad breath measurement techniques. Scientists employ a range of methods for establishing just how bad someone's bad breath is. Some of these are very technical. For instance, gas chromatography separates breath into its constituent molecules, while a halimeter tests the air solely for VSCs.
You might think that researchers are unwilling to use their noses for experiments like this, and sometimes they are - but not for the reason you might think.
Scientists have been measuring oral odor the old fashioned way - with a sniff of the nose - for a very long time. Today, they tend to balk at such a system for one primary reason: its results are difficult to reproduce.
What if one scientist has a more sensitive nose than another? What if a researcher has a head cold one day but not another? What is the correct distance one's nose must be from a patient's mouth for optimal bad breath detection?
Many such factors can make nose-based, or "organoleptic," halitosis measurement unreliable, which is why researchers occasionally avoid it. However, new technology developed by Korean researchers at Seoul University may make this method more reproducible.
Oral health experts at the university's School of Dentistry and Dental Research Institute developed an airtight, syringe-like tube into which patients can blow their breath. After collecting about a cup of stinky air, the researcher may then poke the syringe through the bottom of a paper cup, stick their nose in the cup, inject the air and smell away.
The team found that measurements made this way were very similar to those taken using gas chromatography.
Similar studies, like one in the journal Research and Science, have been conducted to calibrate VSC-measuring technology with nose-based measurements.
If you don't envy oral health professionals and dental researchers for their work, consider improving your own breath with a specialty breath freshening product, like a tongue scraper, alcohol-free rinse or toothpaste without sodium lauryl sulfate (SLS).
By knocking out VSCs and eliminating odor-causing bacteria from the tongue, you may be sparing your dentist some unenviable exposure to halitosis. By avoiding toothpastes with SLS, you may also spare yourself the pain of canker sores.