People plagued by bad breath despite regular brushing, flossing and gargling with mouth wash could benefit from laser therapy, say scientists.

In most cases bad breath comes from the build up of bacteria around the teeth and gums due to poor oral hygiene. But in some the tonsils are to blame, the Israeli team told New Scientist. Treating the tonsils with a laser for 15 minutes to combat bacteria lurking in the tissue can banish these bad odours, they found.

Yehuda Finkelstein and colleagues from the Meir Hospital at the Sapir Medical Centre in Kfar Saba say they successfully treated 53 patients in this way. But critics maintain the best way to alleviate bad breath is regular brushing and flossing. In the study, all of the patients had bad breath due to smelly tonsils rather than dental or gum problems.