Cone-beam computed tomography in orthodontics: benefits and limitations

In order to obtain an overlay-free assessment of dental structures for resorption and ankylosis diagnostics, conebeam computed tomography (CBCT) is being employed more and more often in orthodontics alongside dental CT.

The aim of this study was to investigate the quality and accuracy of CBCT in the imaging of dental structures and to compare it with the imaging quality produced by dental CT. Moreover, we intended to assess the specific advantages and disadvantages of CBCT in clinical use.

The image quality of CBCT and dental CT was examined for a total of 417 teeth and their surrounding structures. 208 teeth were diagnostically recorded using volume tomography and 209 with dental CT. The axial images were assessed for metal and movement artifacts and whether there was an imprecise depiction of the enamel-dentin and pulp interface. The definition and reproductive quality of all teeth were evaluated when imaging the periodontal ligament space in the cervical, middle and apical root thirds.

In contrast to dental CT, metal artifacts were barely apparent in the CBCT and when so, only very feebly, whereas we only observed disruptions in image quality from movement artifacts with CBCT. Image quality of the dental and surrounding bony structures was far better with dental CT on the whole than it was with CBCT. During imaging by CBCT, the periodontal ligament space either could not be, or if so, then only poorly assessed for 86% of the teeth, while this figure was only 20% for dental CT. Furthermore, the enamel-dentin interface and pulp cavity's edges were on the whole much more sharply defined in the dental CT.

Dental CT still represents the gold-standard for inspecting the dental roots and their surrounding bone.