The bacteria that cause halitosis can live on virtually any surface in the mouth. However, some surfaces are more likely to contribute to oral odor than others. This is the conclusion of a study conducted by scientists at the Nippon Dental University in Japan.
Their research, which was published in the journal Odontology, found that microbes that grow on the tongue are much more likely to create a noticeable smell than those that grow beneath the gum line. Coming to this conclusion involved taking samples of saliva from these two areas to see which microorganisms grow where.
The team took samples from more than 60 participants. After identifying and measuring the levels of specific bacteria in the mouth, scientists then measured bad breath levels using a number of techniques. They used gas chromatography, halimeters and organoleptic measurement - meaning smelling with your nose - to estimate bad breath levels.
Researchers also looked at the amount of plaque on teeth and coating on the tongue. They found that two bacteria, Fusobacterium nucleatum and Treponema denticola, contributed most to oral odor, and only when found in tongue deposits.
Beating bad breath means getting rid of these flora and the smells they produce. A vigorous tooth brushing followed by a specialty breath freshener may do the trick.