Women taking tablets to protect their bones from osteoporosis could be at risk of serious jaw damage, claim researchers.
A study suggests that drugs such as Fosamax could be linked to a condition that can lead to long-term infection or even destruction of the jawbone.
As many as one in 25 users could be at risk of osteonecrosis of the jaw (ONJ), according to the study.
British dentists are calling for doctors to advise women about ONJ when prescribing drugs to prevent bone-thinning, and for any major dental work to be carried out first.
But they stressed that women should not stop taking the drugs, called bisphosphonates, as the benefits outweigh the risk of possible side effects.
Researchers at the University of Southern California School of Dentistry studied 208 healthy patients who had taken Fosamax tablets.
The report in the Journal of the American Dental Association said they found nine patients had ONJ (one in 25) – despite claims from the manufacturer Merck that the risk was largely confined to patients receiving the drugs intravenously.
Parish Sedghizadeh, assistant professor of clinical dentistry, believes the problem is more likely to be triggered by tablets than previously thought, although the study has been dismissed by