Evidence Based Referral (Selection) Criteria for CBCT

Referral Criteria

Referral (or selection) criteria are a type of clinical guideline, designed to help in the process of justification of an X-ray examination. Guidelines have been defined as:

"systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances" (Field & Lohr, 1992).

A guideline is not, however, “a rigid constraint on clinical practice, but a concept of good practice against which the needs of the individual patient can be considered” (Royal College of Radiologists, 1998).


Not all guidelines are equal, however, and attention needs to be given to their method of development. Three levels of sophistication can be identified:

1. “Expert” opinion

This is the traditional, and weakest, type of guideline produced by one or more [often self-appointed] individuals. It uses the valuable resource of specialised expertise and experience to present an opinion. Such guidelines have a high risk of bias. Even where a panel of several people is involved, there is a danger of one dominant individual influencing a decision.

2. Consensus opinion

This may have some advantage in that a methodology may have been used to arrive at consensus, but frequently such guidelines represent little more than expert opinion.

3. “Evidence-based” development

This should be the strongest method of producing any guideline. A clear methodology is used, based upon systematic review of literature, critical appraisal and data assessment, culminating in the production of a guideline statement carrying an evidence grade. Methods for performing evidence-based guideline development have been published. In medical radiology, the “European Referral Guidelines for Imaging” (2001), modelled closely on a UK Royal College of Radiologists document (Royal College of Radiologists, 1998), used such an approach.


Regardless of the process of guideline development, it is important to remember that no guideline has an infinite life. Technology undergoes improvements with time and research evidence of clinical efficacy may change. Any guideline should be reviewed at regular intervals to take such developments into account.


Referral criteria for CBCT

CBCT for dental use is a relatively new imaging technique. In this case there is a risk that custom and practice may develop in advance of research evidence, leading to possible overuse of CBCT. As a response to this, SEDENTEXCT has developed "Provisional" Guidelines that include Referral Criteria.



European Commission. Radiation Protection 118. Referral Guidelines for Imaging. Luxembourg: Office for Official Publications of the European Communities, 2001. http://ec.europa.eu/energy/nuclear/radioprotection/publication/doc/118_en.pdf

Royal College of Radiologists. Making the best use of a department of clinical radiology: guidelines for doctors. Fourth edition. Royal College of Radiologists, London, 1998.

 Field, MJ, Lohr, KN, (eds). Guidelines for clinical practice: from development to use. National Academy Press, Washington D.C., 1992.