CBCT: Are Dentists Over-Exposing Patients?

Recently, there has been some hot discussion regarding exposure concerns due to utilizing CBCT.  Most notably, was an article published in the NY Times in Nov. 2010.  If you haven’t read this article, please take a moment to do so.  A significant argument the author focused on was dentists who scan every patient 2 or 3 times or who use the machine as a screening device or profit center by scanning every patient.  For the orthodontic community, the major concern is with adolescents & children which are much more susceptible to radiation vs. an adult.   

In a rebuttal response to many dentists and radiologists who were attacking the NY Times for writing this article, Dr. Farman, President of the American Academy of Oral & Maxillofacial Radiology had this response:

The New York Times folk researched this CBCT topic diligently for 2-3 months and checked every fact many times before going to press. They chose radiation dose to children as the key topic and included reference to D-speed film causing 60% excess dose over other available methods... as well as making reference to "routine" use of CBCT specifically for orthodontic purposes. They used reference to AAO, AAOMR, AAE and EC/Sedentex guidelines in indicating that some continuing education and publications provided to the profession are outside the mainstream. I consider this to be excellent journalism as it did not attack the modality of CBCT, but rather the ignorance of some of its users and its injudicious usage. 

Allan G. Farman, BDS, PhD, MBA, DSc, Diplomate ABOMR

Prof. Radiology & Imaging Science

Univ. Louisville School of Dentistry: SUHD

“All these different cone-beam CT scanners came out to a world that was unprepared, said Keith Horner, a professor of oral radiology at the University of Manchester in Britain, who is coordinating a study of cone-beam scanners for the European Commission (attachment). They are just pushed out there by manufacturers with the message that a 3-D image is always going to be better than a 2-D image, and that isn’t the case.”.

My concern is that CBCT scanners are being pushed so aggressively by manufacturers and distributors who we all trust and rely upon in the dental community.  For me personally, it is astonishing at the large secondary market of CBCT units when this is a brand new technology.  That can only be for two reasons, and both are not positive for the dental industry; 1) due to the rapid technological obsolescence factor of this evolving industry dentists are flipping and losing money for newer machines, and 2) once the dentist has the machine in their office, they realized that the costs to operate and maintain this advanced imaging modality was much more than what they had anticipated.  Either way, both of those reasons build a strong case why CBCT scans should be outsourced similar to the medical model. 

In conclusion, CBCT, like any ionizing radiation source should be used cautiously and the ALARA principles need to be followed.  The fact remains that CBCT, when compared to Medical CT’s is 95 – 99% less radiation and an iCat scan from iMagDent is less than half of an analog FMX.  CBCT does not replace the PA, but is a complementary tool when ossesous structures are involved.  The AAOMR executive opinion statement offers this to us regarding when CBCT is appropriate, Generally accepted guidelines state that CBCT should be used as an adjunctive diagnostic tool to existing dental imaging techniques for specific clinical applications, not as a screening procedure for oral pathology, dental caries detection and/ or assessment of periodontal destruction.