title: Evaluation of linear measurements of implant sites based on head orientation during acquisition: An ex vivo study using cone-beam computed tomography.
abstract: OBJECTIVE
  This study evaluated the effect of various head orientations during cone-beam computed tomography (CBCT) image acquisition on linear measurements of potential implant sites.
  
  
  METHODS
  Six dry human skulls with a total of 28 implant sites were evaluated for seven different head orientations. The scans were acquired using a Hitachi CB-MercuRay CBCT machine. The scanned volumes were reconstructed. Horizontal and vertical measurements were made and were compared to measurements made after simulating the head position to corrected head angulations. Data was analyzed using a two-way ANOVA test.
  
  
  RESULTS
  Statistical analysis revealed a significant interaction between the mean errors in vertical measurements with a marked difference observed at the extension head position (P<0.05). Statistical analysis failed to yield any significant interaction between the mean errors in horizontal measurements at various head positions.
  
  
  CONCLUSIONS
  Head orientation could significantly affect the vertical measurements in CBCT scans. The main head position influencing the measurements is extension.
authors.affiliation: Section of Oral and Maxillofacial Radiology, Department of Oral Diagnostic Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
authors.forename: Hanadi
authors.initials: H
authors.lastname: Sabban
authors.affiliation: Section of Oral and Maxillofacial Radiology, Department of Oral Diagnostic Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
authors.forename: Mina
authors.initials: M
authors.lastname: Mahdian
authors.affiliation: Section of Prosthodontics, Department of Reconstructive Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Dhingra
authors.affiliation: Section of Oral and Maxillofacial Radiology, Department of Oral Diagnostic Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
authors.forename: Alan G
authors.initials: AG
authors.lastname: Lurie
authors.affiliation: Section of Oral and Maxillofacial Radiology, Department of Oral Diagnostic Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
authors.forename: Aditya
authors.initials: A
authors.lastname: Tadinada
keywords: Cone-Beam Computed Tomography; Dental Implants; Dimensional Measurement Accuracy; Patient Positioning