Could bed-wetting be linked to breathing problems? In some cases, scientists think so and say the solution could be quite simple.

Two small studies in Sweden and Britain have shown bed-wetting children with a narrow palate in the upper part of the mouth were helped when a dental device similar to a brace was used to widen the palate.

Derek Mahony, an orthodontist in Sydney, Australia, will soon begin a study of 100 bed-wetting children to see if he comes up with the same findings.

If his results confirm those of the smaller studies, it could help persuade people to start taking the idea more seriously, a report in the New Scientist magazine claimed yesterday.

Seven out of 10 children in the Swedish study and all 10 in the British research improved after one month of using the device.

Scientists are not sure how breathing problems could cause bed-wetting, or enuresis, which affects about one in 10 six-year-olds. But the magazine says there are a few theories.

One is that breathing problems create a physical pressure in the abdomen that stimulates urination.

Another is that the breathing problems lead to low blood oxygen concentrations, which in turn could affect level of hormones involved in urine production.

Bed-wetters with adenoid and swollen tonsils showed improvements after surgery to remove them which, the magazine suggests, supports the hormone theory.

The magazine article goes on to suggest that it is not just children who could benefit. Anecdotal evidence suggests that some adults with breathing problems such as sleep apnoea (brief breathing interruptions during sleep) also wet their beds.