Who has halitosis, and who only thinks they do?

Hundreds of studies have addressed the causes of, prevalence of and treatments for bad breath. But have any touched on whether we can detect our own halitosis? The ancient Greek maxim tells us to know ourselves. Well, how well do we know our own mouths?

According to a pair of new studies, not very well.

Sniff your breath, then check yes or no

Apparently this is a popular topic lately, because in the past year, two separate studies have addressed our ability to detect our own oral odor.

The first was published in June 2011 in the journal Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology. Conducted by Japanese researchers from the Tokyo Medical and Dental University, the study compared two things: people's estimation of their breath odor, and then halimeter-based readings of their actual halitosis levels.

After testing 565 individuals in this way, the team came to a stunning conclusion: People really have very little idea of how badly their breath smells.

In all, participants could correctly identify that they had smelly breath just 48 percent of the time, or roughly the rate they would achieve if they were simply guessing. When asked if they didn't have halitosis, individuals did slightly better, getting it correct 59 percent of the time.

Do you think you could do better? Maybe you're ready to question these findings. If so, take a look in the March 2012 issue of the journal Acta Odontologica Scandinavica, where a different study came to almost the exact same figures.

Twin investigations, twin results

Okay, so maybe it shouldn't be surprising, considering that the two reports share the same lead author: Thuy A. V. Pham of the National Hospital of Odonto-Stomatology in Ho Chi Minh City, Vietnam.

Still, the similarities are impressive. After performing another survey among 252 people, Dr. Pham found that just under one-half (47 percent) of participants could correctly identify when they had halitosis.

Pham went a step further this time and compared the ability to estimate one's oral odor with the level of the funk, e.g. strong, mild or nonexistent. Interestingly, people with no halitosis were best at determining their odor level (they were right 53 percent of the time).

After that came folks with very stinky breath, who correctly estimated their odor level in 47 percent of cases. Finally, dead last were the participants with mild halitosis, who only pinpointed their bad breath potency 33 percent of the time.

The moral of the story

Clearly, the takeaway of these studies is that halitosis is no easy condition to notice in oneself, especially when it's mild. This makes proactive oral care a must. If you'd like to stay one step ahead of your bad breath, turn to specialty breath fresheners for help. You can make use of all-natural toothpastes, mouthwashes, lozenges and mints, in whatever combos you like.

While you're at it, here's a tip for smelling your own breath: Don't breathe into your hands. This common method looks effective, but it simply doesn't work (as the studies above proved handsomely). All you'll detect is the scent of your palms.

Instead, try licking the back of your hand and sniffing it. This will give you a truer picture of your odor level. For extra accuracy use a cotton swab or white plastic spoon to gently scrape the back of your tongue. If it comes back yellow or smelling funky, then you almost certainly have halitosis.