I recently went to the dentist and had a panoramic (PAN) x ray. The dental hygienist took it four times because the first three times there was no image. The dental hygienist told me it was a hardware error before noticing the machine was set on “testing mode.” I was wearing lead apron, and this was my first time getting a PAN done. I am concerned about the exposure I got. Would it be posing any health risk?

You can rest assured that you did not receive any exposure from the first three “attempts” when the panoramic x-ray machine was in testing mode. X-ray machines that revolve around the patient’s head, like this one does, frequently have a “testing mode” that can go through the entire cycle without x rays. It is sometimes used when there are concerns that the machine might touch the patient’s shoulders when it revolves, which can lead to a blurry image. By trying it out first without x rays, they can make any patient position adjustments necessary to avoid contact. The test mode can also be used to demonstrate to a patient how the machine works. It sounds like in your situation someone at the office had used the test mode but did not return the controls to the active mode afterwards.

By the way, the panoramic radiograph (PAN) is the lowest dose imaging technique used in dentistry. It provides a wide view of all the dental structures, as well as the temporomandibular joints (jaw joints).

Sharon L. Brooks, DDS, MS

Professor Emerita, University of Michigan School of Dentistry

Dip., American Board of Oral and Maxillofacial Radiology

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