I have been living under a rock and completely missed the recent media reports which link dental xray exposure to meningioma tumours (usually benign tumours, which appear on the brain membranes). To put your mind at ease, we are publishing communication received from the Australian Dental Association, which explains a bit more about the study from Yale University, reported in the media.
Please remember that at The Dentist, we believe in Xray protocols which need to be custom-designed for each patient, depending on their risk of disease. We only take radiographs if the benefit of information we receive from them far exceeds the risk of over-exposure.
Dear Dr Nesic-Fisher
There has recently been extensive media interest in an article from the Yale University School of Medicine from the USA proposing a relationship between dental radiographs and meningioma.
The article by Claus et al, ‘Dental X-Rays and Risk of Meningioma’, was recently published in CANCER, a peer-reviewed journal of the American Cancer Society.
The study compared patient-reported dental x-ray history of 1433 people who had been diagnosed with meningioma with a control group of 1350 individuals. It found that patients who had received frequent dental x-rays in the past had an increased risk of developing meningioma, the most commonly diagnosed tumour in the United States.
In the article, the authors acknowledge shortcomings in their study, namely:
- Today’s patients now receive lower doses of radiation than in the past. This reduction in dose is due to better equipment, faster x-ray films and increased use of digital radiography. Some of the subjects in the study received dental x-rays decades ago when radiation exposure was greater.
- As a case-controlled study, the study was prone to bias. The results relied on the individuals’ memories of having dental x-rays taken years earlier. The authors recognised that recall bias is common where patients who have experienced a disease are more likely to remember details of their medical history than those people who are the disease-free controls.
In public statements, the Australian Dental Association (ADA) has reassured the public that:
- X-rays are a vital diagnostic tool in dentistry and assist in providing information about a patient’s oral health such as early-stage tooth decay, periodontal disease, infections, problems in surrounding bone or some types of tumours; revealing potential problems in the teeth that simply cannot be observed by the naked eye;
- Much lower doses of radiation are used now as compared to those that would have been used by those involved in the study;
- Dentists are required to undertake regular training in the use of x-rays so as to maximise safety for patients and the dental profession maintains a high standard of radiation hygiene for patients and staff;
- Dentists are very aware of their responsibility in the appropriate use of dental x-rays depending on the clinical presentation of their patients. Therefore there is no reason to decline x-ray examination when advised by their dentist.
- US Studies have revealed that the levels of radiation to which patients are exposed with a single dental x-ray is 0.0067% of the level of exposure from a mammogram or 0.5% of the level of exposure from an aeroplane flight from the equivalent of Sydney to Perth.
If patients express concerns based on media reports of this issue, dentists should reassure the patient of the reason for the x-ray examination and the protocols that are in place to ensure that the delivered radiation dose is as low as reasonably achievable.
Patients have the right to decline the use of x-rays. If a patient does take this course of action, then the dentist should specifically warn the patient that some dental disease may remain undetected and therefore untreated until more serious symptoms present. Please ensure that a note to this effect is recorded in the patient’s record.
It is recognised, however, that the effects of ionising radiation are cumulative and so dentists must remain vigilant that x-rays are only utilised in the appropriate manner.
F. Shane Fryer