Reliability and accuracy of assessing temporary anchorage device-tooth root contact with cone-beam computed tomography.

ABSTRACT

INTRODUCTION: This study was aimed at investigating the reliability and accuracy of cone-beam computed tomography (CBCT) diagnosis of contact between a temporary anchorage device (TAD) and tooth root and assessing any effect produced by metal brackets, imaging software program, and image segmentation or color enhancement tools. METHODS: Eighteen fresh pig mandibles were used. TADs (Vector, 1.4 × 8 mm) were placed at the buccal intermolar alveolar bone on both sides of the mandibles. With soft tissue kept intact, each mandible underwent CBCT scans (voxel size, 400 µm) before and after placing TADs, and after placing metal brackets on involved molars. Alveolar bone specimens containing the TADs were then exposed to microcomputed tomography (microCT) scans (voxel size, 27 µm) after TAD removal. Two independent raters, blinded of image identity, diagnosed TAD-root contact using ImageJ (National Institutes of Health and the Laboratory for Optical and Computational Instrumentation, University of Wisconsin, Madison, Wis) for microCT; Dolphin (Dolphin Imaging and Management Solutions, Chatsworth, Calif) and Anatomage software programs (Anatomage, Santa Clara, Calif) for CBCT images. Intrarater and interrater reliability and diagnostic accuracy were statistically assessed using Cohen kappa and McNemar tests. RESULTS: Intrarater and interrater reliability of TAD-root contact diagnoses were perfect for microCT diagnoses (κ = 1), generally moderate to good (κ >0.5) for CBCT diagnoses except for the use of color enhancement tools (κ <0.25). For diagnostic accuracy, there was generally a low agreement (κ <0.45) between CBCT and microCT (gold standard). The percent accuracy ranged from 68.1% to 79.2% and was not different among raters, bracket presence/absence, or software choices (chi-square tests, P >0.05). Overall, diagnostic sensitivity was above 80%, whereas specificity was below 55%. CONCLUSIONS: Despite good reliability, diagnoses of TAD-root contact using 400 µm voxel size CBCT imaging tend to be inaccurate, with a likelihood of high false-positive diagnoses.