Archive for June, 2014

Dental x-rays: What’s in Your Dose

Monday, June 2nd, 2014

By Dr. Dale Miles, BA, DDS, MS, FRCD (C), Diplomate American Board of Oral Maxillofacial Radiology

Doctor with xray

It doesn’t matter whether it’s a periapical, bitewing a panoramic or even a cone beam CT x-ray examination, our patients always seem to be questioning us as to the need for the x-ray. There isn’t a week, possibly even a day, that goes by the dental practice where a dental assistant, dental hygienist her dentist doesn’t hear the following question from the patient, “Why do I need these x-rays?”. And, unfortunately our answers are usually “all over the map”.

“Don’t worry Mr. Jones it’s just like spending one hour in the sunshine.” Don’t worry about Johnny Mrs. Smith it’s like flying across the country in an airplane.” Obviously somewhere at sometime the dentist or auxiliary has been told, heard in the lecture 10 years ago or read in the magazine a comparison made for dental x-rays to everyday activities. Patients are now becoming more sophisticated and actually are demanding real answers and real information to their questions. It is not appropriate to offer them a platitude without any data. It just isn’t that professional. And it doesn’t instill confidence.

The data is out there, and it’s somewhat easy to find. But searching for it really isn’t high on the list of tasks for most of us. In addition, talking about “milliesieverts” is just as foreign to many dentists and auxiliaries as it is to their patients. There is real data about the approximate dose for each x-ray modality, from periapical to cone beam imaging. You can find studies that look at receptor types with round versus rectangular collimation, studies that compare the dose from a panoramic to a certain number of periapicals and x-ray dose even between the various cone beam machines. However, with the myriad of factors that affect x-ray dose, from something as simple as our KV or MAs settings, or the fact that not all cone machines have the same size FOV (field of view), the dose data can be confusing.

So how do we answer our patients question. To date, the best data, or at least the best way that I found for you to use to talk to your patients about x-ray dose actually compares the risk equivalents of dying from everyday activities to the dental x-ray procedure we call on FMS (full mouth series).  Of course even this data comes from comparisons to a full mouth series of film-based radiographs. However, there are still 55% of us out there dental practice using film, despite the fact that faster receptors are available which also will reduce patient x-ray dose.

So, if this initial blog on x-ray dose doesn’t stimulate conversation, nothing will in the dental profession. You need to seek out good data, use something called selection criteria when determining the need for an x-ray exam and transition to the fastest receptors possible and rectangular collimation, which is now been made simple, in order to protect your patient in the best manner possible. Are you up to the task?

Time now to start peppering me with the questions which I’m sure will arise from this initial blog posting. I look forward to your comments and questions. BTW, this is the first time that I’ve accepted an invitation to “blog”. My time, like yours, has become my most precious commodity. But I’m willing to help you find the answers you seek.



Dr. Miles is a diplomate of the American Board of Oral and Maxillofacial Radiology and the American Board of Oral Medicine. He has authored over 130 peer-reviewed articles and 6 textbooks, including the best selling atlas on Cone Beam CT, Color Atlas of Cone Beam CT for Dental Applications published by Quintessence Publishing. Dr. Miles is in full-time practice of Oral and Maxillofacial Radiology in Fountain Hills, Arizona. He is the President and CEO of Cone Beam Radiographic Services, LLC., a CBCT reporting service for dentists and dental specialists and President of EasyRiter, LLC, which produces a simple CBCT report generating software for the profession.