Comparison of Tooth Length Measurements Made on CBCT and 3T MR Images
Objective: The aim of this study is to compare tooth length measurements made on cone beam computed tomography (CBCT) scans and 3-Tesla (3T) magnetic resonance (MR) scans. Materials and Methods: One CBCT scan (NewTom5G, AFP Imaging, USA) and one 3T MR scan (Siemens Medical Solutions, DE) as performed on 12 subjects. CBCT images were captured with an 18x16 inch field of view that covered the whole head. Contiguous sagittal MR images of the whole head were produced in a 3.0T imaging system with a T1-weighted 3D imaging sequence (Magnetization Prepared Rapid Acquisition by Gradient Echo (MP-RAGE), TP/TE = 1950/2.26 ms) and isotropic resolution of 1.0x1.0x1.0 mm. DICOM formatted images from each scan were oriented in all three planes of space and 4 mm thick slices were made through the long axis of all permanent teeth. Tooth length measurements were determined from the slices (336 tooth length measurements) using Invivo (v5.4) imaging software (Anatomage Inc., San Jose, CA). Results: Overall data showed good correlation with Intraclass Correlation Coefficient of 0.981 (P<0.001) and Pearson’s Correlation of 0.981 (P<0.001). The mean difference between the collective measurements was 0.04 mm ± 0.77 mm. Measurements in the maxilla (ICC 0.982) had slightly higher correlation than those in the mandible (0.980). Second premolars were found to have the highest correlation of all tooth types (ICC 0.984, P<0.001). Conclusions: Measurements made of 3T MR images have good correlation with equivalent CBCT measurements. Larger sample size is required to evaluate differences found in data. Future studies are required to evaluate MRI as a diagnostic imaging modality in the field of orthodontics.
Dentistry, Medicine and Health Sciences, Orthodontics and Orthodontology, Orthodontics; Tooth - Radiography; Cone-Beam Computed Tomography; Magnetic Resonance Imaging; Imaging - three dimensional;, Diagnostic imaging modalities; Tooth length measurements; MRI tooth length measurements; CBCT scans
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