Frequent dental X-rays may significantly increase the risk of non-malignant brain tumours, say researchers.
Over a lifetime, having dental X-rays can double or triple the chances of developing meningioma tumours, a study has found. The tumours grow in the outer membrane covering the brain. In one case, involving X-rays on children, a five-fold increase in risk was seen.
However, the likelihood of developing a brain tumour at all is very small. Meningiomas, which account for about one in five primary brain tumours, affect two or three in every 100,000 people in the UK each year.
The tumours are slow-growing, often causing no symptoms, and usually benign.
Scientists in the US looked at the self-reported dental histories of 1,433 patients diagnosed with meningioma tumours. They were compared with a "control group" of 1,350 matched individuals who were free of the disease.
The tumour patients were consistently more likely to have been exposed to dental X-rays.