Reproducibility of landmark identification in the jaw and teeth on 3-dimensional cone-beam computed tomography images

Abstract

Objective: To compare the reproducibility of landmark identification on three-dimensional (3D) conebeam computed tomography (CBCT) images between procedures based on traditional cephalometric definitions (procedure 1) and those tentatively proposed for 3D images (procedure 2). Materials and Methods: A phantom with embedded dried human skull was scanned using CBCT. The acquired volume data were transferred to a personal computer, and 3D images were reconstructed. Eighteen dentists plotted nine landmarks related to the jaws and teeth four times: menton (Me), pogonion (Po), upper-1 (U1), lower-1 (L1), left upper-6 (U6), left lower-6 (L6), gonion (Go), condyle (Cd), and coronoid process (Cp). The plotting reliabilities of the two procedures were compared by calculating standard deviations (SDs) in three components (x, y, and z) of coordinates and volumes of 95% confidence ellipsoid. Results: All 27 SDs for procedure 2 were less than 1 mm, and only five of them exceeded 0.5 mm. The variations were significantly different between the two procedures, and the SDs of procedure 2 were smaller than those of procedure 1 in 21 components of coordinates. The ellipsoid volumes were also smaller for procedure 2 than procedure 1, although a significant difference was not found. Conclusions: Definitions determined strictly on each three sectional images, such as for procedure 2, were required for sufficient reliability in identifying the landmark related to the jaws and teeth. (Angle Orthod. 2011;81:843-849.)

Experimental and clinical assessment of three-dimensional cephalometry: A systematic review

“…An additional search with the same search equation, performed using Google Scholar, found 6 new articles. The final number of articles was 21 (Berco et al, 2009;Bholsithi et al, 2009;Fuyamada et al, 2011;Gribel et al, 2011;Hassan et al, 2009;Lagrav ere et al, 2009Lagrav ere et al, , 2010Ludlow et al, 2009;Medelnik et al, 2011;de Oliveira et al, 2009;Olszewski et al, 2007Olszewski et al, , 2008Olszewski et al, , 2010Olszewski et al, , 2013Oz et al, 2011;Periago et al, 2008;Schlicher et al, 2012;Titiz et al, 2012;Varghese et al, 2010;Zamora et al, 2012Zamora et al, , 2011). An assessment of the risk of bias revealed that none of the articles met the adopted criteria.…”

Assessment of asymmetry in a normal occlusion sample and asymmetric patients with three-dimensional cone beam computed tomography

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How Do Landmark Deviations Affect Angular Measurements? The Concept of Individual Cephalometric Calibration

“…One solution to this problem would be the use of tentative landmark definitions. Fuyamada et al [19] showed that using separate definitions of landmark locations on each axis significantly improved the selection accuracy. This method could also reduce the time required to implement any necessary corrections.…”