title: The accuracy of linear measurements of maxillary and mandibular edentulous sites in cone-beam computed tomography images with different fields of view and voxel sizes under simulated clinical conditions.
abstract: OBJECTIVE
  The objective of this study was to investigate the effect of varying resolutions of cone-beam computed tomography images on the accuracy of linear measurements of edentulous areas in human cadaver heads. Intact cadaver heads were used to simulate a clinical situation.
  
  
  METHODS
  Fiduciary markers were placed in the edentulous areas of 4 intact embalmed cadaver heads. The heads were scanned with two different CBCT units using a large field of view (13 cm×16 cm) and small field of view (5 cm×8 cm) at varying voxel sizes (0.3 mm, 0.2 mm, and 0.16 mm). The ground truth was established with digital caliper measurements. The imaging measurements were then compared with caliper measurements to determine accuracy.
  
  
  RESULTS
  The Wilcoxon signed rank test revealed no statistically significant difference between the medians of the physical measurements obtained with calipers and the medians of the CBCT measurements. A comparison of accuracy among the different imaging protocols revealed no significant differences as determined by the Friedman test. The intraclass correlation coefficient was 0.961, indicating excellent reproducibility. Inter-observer variability was determined graphically with a Bland-Altman plot and by calculating the intraclass correlation coefficient. The Bland-Altman plot indicated very good reproducibility for smaller measurements but larger discrepancies with larger measurements.
  
  
  CONCLUSIONS
  The CBCT-based linear measurements in the edentulous sites using different voxel sizes and FOVs are accurate compared with the direct caliper measurements of these sites. Higher resolution CBCT images with smaller voxel size did not result in greater accuracy of the linear measurements.
authors.affiliation: Department of Diagnostic Sciences, Division of Oral and Maxillofacial Radiology, Tufts University School of Dental Medicine Boston, MA, USA.
authors.forename: Rumpa
authors.initials: R
authors.lastname: Ganguly
authors.affiliation: Department of Diagnostic Sciences, Division of Oral and Maxillofacial Radiology, Tufts University School of Dental Medicine Boston, MA, USA.
authors.forename: Aruna
authors.initials: A
authors.lastname: Ramesh
authors.affiliation: Department of Public Health and Community Service, Tufts University School of Dental Medicine, Boston, MA, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Pagni
keywords: Cadaver; Cone-Beam Computed Tomography; Dental Implants; Imaging, Diagnostic