Work package 4: Diagnostic Accuracy

This package addresses key issues of “Diagnostic Accuracy” with CBCT. There are a multitude of diagnostic applications of radiology in dentistry. These can be broadly divided into implant-related, other (non-implant) surgical, orthodontic and other uses. The existing literature in this subject is considerably diluted by numerous non-systematic reviews and single case reports. Such opinion-led papers, invariably enthusiastic in their support for using CBCT, add little to our knowledge of diagnostic accuracy. Ideally research on diagnostic accuracy should be prospective and use a recognised reference standard (‘gold standard’) measure of truth as a reference against which a diagnostic method can be assessed. Most existing studies in the literature do not satisfy these criteria.

Orthodontic radiology is a key clinical condition for which CBCT may be used. Most orthodontic treatments are performed in the first or second decades of life, when radiation-related risk is highest. Concerns over the use of x-rays in orthodontic treatments has been highlighted in the European Guidelines on Radiation Protection in Dental Radiology (European Commission, 2004), emphasising the need for careful clinical assessment prior to selecting the need for x-ray imaging. Many patients do not require complex imaging for orthodontic treatment planning and some no imaging at all. This European Commission document included referral criteria for orthodontic treatment but did not consider CBCT as, at that time, there was extremely limited literature available on CBCT use in orthodontics. Preliminary review of the literature by the SEDENTEXCT partners showed that this literature is dominated by anecdotal reports and ‘reviews’ advocating a degree of diagnostic accuracy that cannot be supported by the evidence available.

Similar criticisms can be addressed at publications suggesting the usefulness of CBCT for a range of dental applications, including individual tooth assessments, dental caries, periapical disease, periodontal bone defects, temporomandibular joint problems and various minor surgical procedures including pre-surgical third molar assessment. Some of these studies also fail to demonstrate a strong research methodology, relying on a non-systematic, retrospective selection of case reports to support their conclusions.

Our research targets key clinical applications of CBCT and performs rigorous diagnostic accuracy studies that can make a significant, high quality contribution to knowledge and that can be utilized in referral criteria development. Neither do existing studies illustrate the very important function of the image and observer variability, which are addressed in our research.


The overall aim of this work package is to assess diagnostic accuracy for CBCT for key clinical applications in dentistry. There are several sub-objectives:

  1. To determine in vitro the segmentation, linear and/or diagnostic accuracy of various CBCT scanners versus conventional “medical” CT scanners.
  2. To assess the diagnostic accuracy of CBCT in an animal model.
  3. To determine the diagnostic accuracy of various CBCT scanners for specified clinical applications.