Bad Gums not Bad Brushing Causes Bad Breath

UBC Reports | Vol. 49 | No. 6 | Jun.
5, 2003

Gingivitis is at the root of the problem

By Hilary Thomson

Think brushing, flossing and swigging mouthwash can save
you from bad breath?

Think again.

“There is a common superstition — even among dentists
— that oral hygiene is directly linked to bad breath,”
says Ken Yaegaki, director of the Faculty of Dentistry Breath
Testing Clinic and a world expert on halitosis. “Our
clinical experience doesn’t support that theory at all.”

That’s why Yaegaki has teamed up with colleagues in
Beijing and Tokyo to investigate the primary cause of bad
breath. He is co-supervising the work of primary investigator
Xuenan Liu, a doctoral student at Tokyo Medical and Dental
University. With colleague and co-supervisor Yoko Kawaguchi,
Yaegaki has overseen the study of approximately 2,000 adults
of all ages through interviews and examinations at Beijing
health clinics, schools and local offices of the Communist

The project is the first clinical bad breath study ever done
in China, a country with strong educational links to Japan.

The findings have reversed common thinking to show that gum
disease, not poor oral hygiene, is the primary and direct
cause of bad breath.

Yaegaki hopes the findings will help promote regular trips
to the dentist.

“Even in Canada, almost half the population does not
have regular exams and cleaning,” he says. “I want
to change this behaviour through people’s fear of bad
breath. They may be more motivated to have regular check-ups
to avoid getting the gum disease that leads to bad breath.”

Researchers use a halimeter to test bad breath. The system
uses gas chromatography as a measuring device and provides
precise readings of sulphur compounds, high levels of which
are the basis of bad breath.

Other causes of halitosis include tongue coating from various
health conditions such as diabetes, or liver disease, throat
inflammation or sinusitis, and some medications.

Many remedies, including most mouthwashes are “a little
bit more effective than water,” in combating bad breath,
says Yaegaki. Some products, such as sugar-free mint-flavoured
gums actually worsen halitosis by breaking down tongue coating
and releasing malodorous compounds into the mouth.

Oral hygiene is improving in China as the economy improves,
creating a huge market for tooth cleaning and breath freshening
products, Yaegaki reports. This summer, he will supervise
a post-doctoral fellow from Beijing where two dental schools
have started bad breath clinics and research.

The findings from the recent study will be published at an
international breath odour conference in April 2004.

For more information on UBC’s Breath Testing Clinic,
visit the Web site at
or call 604.822.8028.