A comparative study of the accuracy and reliability of multidetector computed tomography and cone beam computed tomography in the assessment of dental implant site dimensions

Objectives: The aim of this study was to investigate the accuracy and reliability of linear measurements of edentulous ridges recorded from 16-row multidetector CT (MDCT) images and cone beam CT (CBCT) images acquired using a flat panel detector (FPD) with a large field of view (FOV), both independently and in comparison with each other. Methods: Edentulous areas of human dry skulls were marked with gutta-percha markers to standardize the plane of the transverse cross-sections and path of measurements. The skulls were imaged using a 16-row MDCT scanner and a CBCT device with a large FOV and a FPD. Ridge dimensions were recorded from reformatted sections by two observers and compared with measurements recorded directly from the bone. The measurement errors and intra and interexaminer reliability were calculated for each modality and compared with each other. Results: The overall mean of the absolute errors was 0.75 mm for MDCT and 0.49 mm for CBCT. The mean of the CBCT absolute errors was smaller than that of the MDCT absolute errors for the overall data, as well as for the site-specific data. The intraexaminer reliability score was 0.994 for MDCT and 0.995 for CBCT. The interexaminer reliability was 0.985 for MDCT and 0.958 for CBCT. Conclusions: Both MDCT and CBCT were associated with a clinically and statistically significant measurement error. CBCT measurements were significantly more accurate than those of MDCT. The measurements recorded from both modalities had a high inter and intraexaminer reliability. Accuracy of measurements was found to be more operator dependent with CBCT than with MDCT. Dentomaxillofacial Radiology (2011) 40, 67-75. doi: 10.1259/dmfr/27546065