Evaluation of dehiscences using cone beam computed tomography

To validate the use of three-dimensional (3-D) surface rendering (SR) images to quantify the height of alveolar dehiscences.

Twenty-four dehiscences were created on 9 incisors, 9 canines, and 6 premolars on 4 cadaver skulls. i-CAT cone beam computed tomography scans (CBCTs) were taken of each skull at .2 mm voxel size. Each dehiscence was quantified by 21 orthodontic residents using 3-D SR. The principal investigator (PI) also quantified each dehiscence using the 2-D multiplanar (MP) image and the 3-D SR image.

Results of this study showed an average method error of the residents as a group to be 0.57 mm with an intraclass correlation (ICC) of 0.77%. Residents' method error ranged from 0.45 mm to 1.32 mm, and the ICC ranged from 0.201% to 0.857%. Systematic error was low at -0.01 mm for the direct measurement compared with the residents' average 3-D SR at 1365 density value (DV) measurement. The 3-D SR at 1365 DV images were compared with the MP and 3-D SR images at 1200 DV, and no significant differences in measurements and low systematic error were noted. The method error of the PI was 0.45 mm, 0.45 mm, and 0.41 mm for 3-D SR at 1365 DV, 3-D SR at 1200 DV, and 2-D MP, respectively.

3-D SR and 2D MRP can be used to measure dehiscences of the periodontium with similar levels of accuracy.