Laser treatment 'zaps bad breath'
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.
The scientists found no other mouth problems, but when they squeezed and massaged the patients' tonsils there was a foul-smelling discharge, suggesting the problem was fetid tonsils.
In this condition, bacteria collect in the grooves, or crypts, of the tonsils.
All of the patients were then treated with a one 15-minute session of laser therapy to the tonsils.
The were re-examined four to six weeks later to see if the treatment had worked.
Twenty-eight of the patients were cured after the first session and the rest were cured after a further one or two sessions, according to the researchers.
The laser works by vaporising the infected tissue and seals the crypts by creating scar tissue that bacteria cannot colonise.
It can be carried out while the patient is awake in an office setting with the use of an anaesthetic spray to the tonsils.
Richard Price, a consumer adviser to the American Dental Association, said that the procedure could be useful as a last resort, but that tonsils only cause up to 6% of halitosis.
He told New Scientist: "Try conventional treatment first.
"Scraping the tongue and using mouthwash seems to work for most people."
Dr Jonathan Portner, a dentist in North London, said: "I'm certain there is something in it.
"I have had adolescents with this problem."
Dr Philip Stemmer, a private dentist working at the Fresh Breath Centre in the UK, said: "I do not believe it."
He said the tonsils could smell but that they would not smell enough to cause bad breath.
"Having the tonsils out is a waste of time to treat halitosis.
"The problem will still be there. There's not enough bacteria or smell coming from the crypts [of the tonsils]."
He advised people with persistent bad breath despite regular brushing, flossing and using non-alcohol mouth wash to see a dental hygienist.
"Bad breath is due to bacteria. What will help is good oral hygiene and staying well hydrated."