Accuracy and Reliability of Landmarks Identification Using Ultra Low Dose CBCT: An In-Vitro Study

Document Type : Original Article


1 Lecturer, Department of Radiology, Faculty of Dentistry, Cairo University, Cairo, Egypt

2 Lecturer, Department of Orthodontics, Faculty of Dentistry, Cairo University, Cairo, Egypt.


Purpose: The aim of this study was to assess the accuracy of ultra-low dose (ULD) CBCT in orthodontic landmark identification compared with standard dose CBCT on reconstructed lateral and posteroanterior views. Materials and Methods: 10 dry human skulls were scanned twice; once with standard CBCT standard radiation dose, and with ULD CBCT protocol operated at 90 kVp, 7.1 mA, 4.5 sec and 400µm voxel size. From each scan, a lateral and a posteroanterior cephalogram were reconstructed, and 33 landmarks were identified on them by 2 experts. All measurements were then repeated after 2 weeks for intra-observer reliability. Results: There was no statistically significant difference in landmarks identification between ULD and standard dose CBCT. The mean difference between both groups ranged between -0.12 to 0.51 in lateral view and -0.67 to 0.46 in posteroanterior view with excellent inter and intra observer agreement with an ICC value >0.7. Conclusion: Ultra-low dose CBCT with reconstructed lateral and posteroanterior views may be recommended for regular orthodontic diagnostic measurements and can replace the standard dose CBCT


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