We’ve all been there, sitting in the dentist’s chair, fitted with a lead vest, mouth full of contraptions and a whirring machine pointed directly at your head. The nurse pops outside and closes the door, and you wonder just how much radiation is being absorbed into your body.
Research from Yale University’s Department of Public Health has found possible links between frequent dental x-rays and the formation of certain benign brain tumours. Hong Kong orthodontist Derek Baram says while the results are not definitive, they are concerning. “Too many x-rays are taken routinely without much consideration as to why it needs to be done,” he says. “We have to ask ourselves whether the benefits of the x-rays outweigh the risk.”
Dr Baram says the introduction of digital technology in the past decade has significantly reduced the radiation dose per x-ray, thereby decreasing the risk for today’s generation of children. But, he warns, parents should still be wary. “Young children are more prone to radiation than adults because they are growing, their cells multiply faster, and their bones, skin and other connective tissues are thinner as well.”
While x-rays can be vital for ensuring children’s teeth are kept healthy, or in preparation for orthodontic treatment, Dr Baram suggests parents ask their practitioner to ensure all x-rays are clinically justified. “Routine x-rays to check the development of teeth is often not good enough for me,” he says. “There need to be stricter guidelines in Hong Kong, as many dentists and doctors practise defensive medicine, taking more x-rays just in case it picks something up, even when the chance of picking something up is really slim.”
European guidelines suggest most children shouldn’t need dental x-rays until age five at the earliest. If teeth are healthy and there is no cause to suspect decay, it’s recommended to take a two- to three-year break between sets. Only children identified as being at “high risk” for problems should require more regular imaging.
When your child does have an x-ray, ensure they are wearing a lead collar, known as a thyroid collar, to maximise protection. A lead vest may also be beneficial. It’s also better to limit the number of x-rays taken at any one time. For example, taking five x-rays within one week poses more of a risk than taking five x-rays over the span of a year.
And while it’s not the first thing we think about when it’s time to relocate, make sure to bring your child’s x-rays with you, or have the clinic forward the images to your new dentist. It will reduce the need for a whole new set being taken unnecessarily. “This is a great idea in the age of digital x-rays,” says Dr Baram. “Films are difficult to duplicate and can be expensive, but digital x-rays are easy to store and obtain.”
Finally, don’t forget to follow the same advice for yourself. In Hong Kong, we are already exposed to higher levels of radiation with regular air travel and naturally occurring factors. Small steps to limit overall exposure can make a big difference.