Accuracy of Linear Measurements in Stitched Cone Beam Computed Tomographic Images An In-Vitro Stud

Introduction: Cone Beam Computed Tomography plays a major role in all specialties of maxillofacial region. This variability in applications necessitates variability in the available Field of View (FOV). However, large detector size might not be available in some machines. Stitching allows the fusion of 2 or more small volumes to form larger volumes. For that this study was carried out to evaluate the accuracy of linear measurements obtained from stitched CBCT images compared to direct real measurements.
Methodology: Twenty four skulls with mandibles were recruited from Anatomy Department, Faculty of Medicine, Cairo University. Two radiopaque gutta percha markers were glued on each skull and mandible at the nasion and mental ridge (at mid line) respectively. Each skull fixed to its mandible was placed on the CBCT machine Planmeca Pro Max 3D Mid® (Asentajankatu, Helsinki, Finland) in Oral and Maxillofacial Radiology Department at Faculty of Dentistry, Cairo University. For real measurements, the distance between the two markers was measured using digital caliper. The resultant images were evaluated using Planmeca Romexis Viewer version 4.4.0.R (Asentajankatu, Helsinki, Finland) and the CBCT measurements were performed by two blinded observers.
Results: The mean real measurement was 96.12 (±11.42) mm which was slightly greater than that of the CBCT measurement which is 95.43 (±11.39) mm. There was a good agreement between CBCT and real measurements. The level of inter-observer and intra-observer agreement is very strong regarding both real and CBCT measurements
Conclusion: Linear measurements driven from Stitched CBCT images are accurate and reliable for diagnostic purposes in maxillofacial region.