DENTAL X-rays given to millions of Britons every year could dramatically increase the risk of brain tumours, scientists have warned.
A major study has found that dental patients who received frequent X-rays were up to five times more likely to be diagnosed with meningioma, the most common type of brain tumour.
It was radiation transmitted during those examinations that was responsible for the increased risk, the study found.
To investigate the link, researchers from Yale University surveyed 1,433 brain tumour patients between the ages of 20 and 70, comparing them with a similar group of healthy people.
They found that over a lifetime, brain tumour patients were twice as likely to have had a bitewing dental examination, in which X-ray film is held in place by a tab between the teeth.
Individuals who had undergone the procedure more than once a year were nearly twice as likely to develop a brain tumour than those who had none, they found.
An increased risk of meningioma was also linked to whole-mouth panoramic examinations – which are taken externally.
Patients who were given dental X-rays below the age of 10 were nearly five times as likely to develop a brain tumour, the researchers found.
The study was published in Cancer, the journal of the American Cancer Society.
Dr Elizabeth Claus, of Yale’s Department of Epidemiology and Public Health, who led the research, said: “Our findings indicate a statistically significant increased risk with both bitewing and panoramic films.”
But British dentists pointed out that American patients have far more X-ray examinations than in the UK and that today’s patients are exposed to lower doses of radiation than in the past.
Martin Fallowfield, a spokesman for the British Dental Association, pointed out that patients were exposed to more radiation on a flight to Spain.
He added: “X-rays are a vital tool in dentistry and reveal problems in the teeth and surrounding bone that simply cannot be observed by the naked eye, and often before patients experience any pain or discomfort. The earlier dental problems are identified, the easier they are to treat.”