On the list of social offences, bad breath ranks right up there with flatulence and body odour. And while store shelves are well stocked with remedies ranging from chewing gum and mouthwash to breath strips and drops, researchers are just starting to understand the science of bad breath.

"It's taboo," said Patricia Lenton, of at the University of Minnesota's School of Dentistry. "You are typecast as the smelly person." Lenton was one of nearly 200 scientists who attended the International Conference on Breath Odor Research this week in Chicago. Attendees ranged from dentists, chemists and microbiologists to psychologists and even flavour researchers.

Their research ran the gamut from studies on the most effective natural flavours for treating bad breath - cinnamon is a good choice - to the development of an artificial nose for sniffing out oral malodour and links between exhaled air and disease.

"We want to advance the science in this field," said Christine Wu, a researcher at the University of Illinois at Chicago's College of Dentistry. "In dental research, bad breath is neglected because it is not a disease that will kill people," she said. "But it's a huge problem. Everybody suffers from bad breath at one point in their lifetime."

Bad breath occurs when bacteria in the mouth breaks down proteins, producing volatile sulfur compounds that make for foul-smelling breath. Lenton said good oral care is the best weapon for routine bad breath. She recommends regular brushing and flossing, a tongue scraper to remove bacteria from the back of the tongue, and a final rinse with antibacterial mouthwash.