Radiation Risk From Dental Radiography
The amount of radiation received from dental radiography is so low that it is highly unlikely that it results in a measurable risk. Dose reconstructions using techniques commonly used during the last decades of the last century show that the exposure to the brain from 4 bitewings is approximately 0.07 mGy, and from a panoramic examination about 0.02 mGy. A full-mouth examination (typically consisting of 12 periapical and 4 bitewing exposures) results in a brain dose of approximately 0.24 mGy.
However, even though the brain exposure from a full-mouth examination is higher than from bitewings or a panoramic, the study from Claus and colleagues found associations with the 2 low-dose examinations and meningiomas but not the relatively high-dose full-mouth examination. The resolution of this inconsistency is not clear if radiation is causing the meningiomas.
Further, there are no research reports that support the premise that doses as low as those received by the brain from dental radiography, including from a full-mouth examination, are sufficient to cause meningiomas. We know that brain exposure from dental imaging is much smaller than from head CT examinations. Brain exposure from head CT examinations is typically in the range of 43-75 mGy, far more than from dental radiography. Head CT exposures contribute 4.3% of the collective effective dose from all diagnostic sources, 15 times more than from dental radiography.
Previous efforts to link head CT exposures, skull x-rays, or sinus radiographs to meningiomas have been unsuccessful, although recently an association has been reported between multiple radiation exposure from CT scans in childhood and subsequent risk for leukemia and brain tumors. Finally, decades of study of the Japanese atomic bomb survivors as well other exposed populations has not reliably demonstrated evidence of increased cancer risk below 100 mSv . While we believe that dental radiography has the potential to cause harm, including meningiomas, and we concur that the Claus study suggests an association between dental radiographic exposures and meningiomas, it is far more likely because of the low doses involved in dental imaging that the reported association is the result of meningiomas triggering the need for dental imaging than the other way around.