Pilot Study: Comparison of Artifacts of Brackets Using Dual-Energy CT

Studies on the use of monochrome (MC) imaging after implantation of metallic materials on the extremities or spine have shown that artifacts can be significantly reduced. Due to the high atomic numbers and high density of materials used in orthodontics, maxillofacial surgery and tooth preservation, hardening artifacts present a major problem in computed tomography (CT) imaging of the teeth, and jaw. The limitations of the image quality caused by the visualization of the jaw, and conceivable possibilities for improvement have not been adequately investigated. The aim of this work was to investigate the above artifacts and reduce them by creating monochromes in the jaw area. Dual energy CTs (DECTs) were performed on 10 corpse heads with and without orthodontic appliances. Subsequently, MCs of 80 to 160 kV were produced. The artifacts were assessed qualitatively and quantitatively using established methods. On anatomical structures such as the floor of the mouth and the soft palate, which are not in the same axial plane with high artefact producing objects of high atomic number, an increase of the Hunsfield units (HU) could be observed with increasing kV number of MC. On structures in the same plane with artifact-producing objects, a decrease of the HU could be observed with increasing kV number of MC. This study shows that it is also possible to reduce artifacts in the jaw area using MC. In all investigations no significantly increased artifacts were found in the setting with orthodontic appliances compared to the setting without orthodontic appliances.