3D radiography: A brief overview of cone-beam CT

In dentistry, ‘3D radiography’ can be defined as using diagnostic X-rays to obtain a picture of a patient's teeth and jaws in three dimensions. For many decades dentists have used two-dimensional dental radiography, most commonly periapical and bitewing radiographs, and panoramic tomographs. In the mid 1990s, spiral tomography (Scanora^®, Soredex, Finland) was ground-breaking in producing cross-sectional slices in planes parallel and perpendicular to a tangent of the dental arch, but its high cost and complicated operation (over 600 programmes) restricted its use to dental hospitals (Horner et al. 2008).

With the dawn of the 21st century, the latest technology in dental radiography is ‘cone-beam computed tomography’ (CBCT). This technology evolved from radiotherapy techniques and, combined with powerful computer software processing, has become a three-dimensional radiographic technique designed to be used by dentists. There are now over 50 CBCT machines commercially available from over 20 manufacturers, all offering slightly different fields of view, voxel sizes, image receptors, user interface, and software programmes.