title: A comparison between various radiological techniques in the localization and analysis of impacted and supernumerary teeth.
abstract: OBJECTIVE
  An increasing number of different types of commercial cone-beam computed tomography (CBCT) devices are available for three-dimensional (3D) imaging in the field of dental and maxillofacial radiology. When removing impacted or supernumerary teeth, surgical teams often operate adjacent significant anatomical structures such as nerves, vessels, adjacent teeth roots, and paranasal sinuses. It is therefore important to choose the appropriate surgical approach to avoid iatrogenic damage to the essential anatomical neighbouring structures. CBCT, also called digital volume tomography (DVT), can visualize impacted and supernumerary teeth in all standard planes, as well as multisectional 3D views. These devices have shown to be highly beneficial in the assessment of small bony lesions and maxillofacial injuries. However, it is still necessary to determine the effectiveness of such devices in the assessment of impacted and supernumerary teeth, in comparison to the conventional radiological methods of intraoral X-rays and panoramic X-rays.
  
  
  METHODS
  During a period of 2 years, a total of 61 patients of whom majority had impacted teeth or supernumerary elements in the frontal maxillary region were studied with CBCT and treated at the St. Olavs University Hospital. Patients were referred to our Department of Oral and Maxillofacial Surgery with both conventional and digital intraoral X-rays and/or panoramic X-rays. None had any acute infections or odontogenic abscesses, and most presented with asymptomatic impacted tooth. A comparison between the preoperative conventional and the CBCT images, the resulting diagnoses, and the intraoperative findings as "gold standard" were made and recorded in a compiled scoring sheet. The objects of interest were researched with the magnification method. Each patient was identified only with a patient number.
  
  
  RESULTS
  In contrast to the conventional X-rays, the pre-surgical evaluation with the CBCT revealed detailed imaging of significant anatomical structures and objects of interest, with highly accurate anatomical and morphologic imaging, when compared to the intraoperative findings. Furthermore, no diagnostic problems, in relation to the anatomical localization, occurred preoperatively.
  
  
  CONCLUSIONS
  The CBCT provides true and precise anatomical information with high surgical predictability without distortion or artefacts, and is superior to conventional radiography. It enables more time-efficient surgeries and reduces costs and surgical complications.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Norwegian University of Science and Technology (NTNU), St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Ziegler
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Klimowicz
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging*; D008875:Middle Aged; D009664:Norway; D019252:Radiography, Dental, Digital / Q000295:instrumentation*; D014095:Tooth, Impacted / Q000000981:diagnostic imaging*; D014096:Tooth, Supernumerary / Q000000981:diagnostic imaging*