Although the study authors suggested their findings might prompt a re-examination of current recommendations, Dr. Alan G. Lurie, president of the American Academy of Oral and Maxillofacial Radiology said the new paper "does not do one iota to change the need to follow the As Low As Reasonably Achievable (ALARA) principle."
"No matter how low the dose gets, it's more than zero," Lurie said, "so you need to have a good reason" for the X-ray, he said. Patients should ask their dentists: "What is it going to tell you that will help you decide how to treat me?"
The study had two principal weaknesses, beginning with people's notoriously unreliable recall for past events, in this case past X-rays, and the lack of data on what doses of radiation they received. "You would want to know the radiation dose to the part of the brain where the meningioma occurred," said Dr. Henry D. Royal, a nuclear medicine specialist at the Mallinckrodt Institute of Radiology in St. Louis, who said that dose "should be trivial." He pronounced the paper flawed.
In his 2009 book, "Brain Surgeon: A Doctor's Inspiring Encounters with Mortality and Miracles," Black expressed his concern about frequent X-rays among youngsters undergoing orthodontia because they're "aimed not just at the jaw, but at the lower brain." An advocate for minimizing the use of X-rays in dentistry, Black said he routinely refuses dental X-rays. "I haven't had a dental X-ray in 20 years."
Although children's developing teeth are more prone to decay than those of adults, sometimes requiring more X-rays, their bodies also are more vulnerable to the effects of radiation.
Dr. Robert J. Emery, executive director for environmental health and safety at the University of Texas Health Science Center in Houston, suggested patients ask their dentists if the X-rays are "absolutely necessary," what radiation doses will be delivered, and if they use lead aprons and collars to shield organs vulnerable to radiation's effects. He also recommends that when patients first see a new dentist, they bring along copies of previous X-rays.
Dr. Paul Casamassimo, chair of pediatric dentistry at Ohio State's College of Dentistry, was even more emphatic about questioning dental X-rays: "My advice would be to challenge your dentist on why radiographs are needed in any given situation, particularly when a child is involved."
ABC News Medical Unit's Dr. Jessica Noonan contributed to this report.