Three-dimensional location and distribution of the center of resistance in the maxillary first molar applied to occlusal force

Abstract

We aimed to investigate the center of resistance (CRes) of the maxillary first molar to set the occlusal force through finite element analysis. The inclination of the molar was measured, with loading to the root on the crown, and the position and direction of the load that minimized the inclination were investigated. The CRes was defined as the set of midpoints of the minimum distances between the two lines. Nine hundred and ninety CRes points were estimated from forty-five lines. The CRes was estimated as the point 1.22 mm (Z), −0.74 mm (X), and 0.23 mm (Y) from the origin in the apical, distal, and buccal side directions, respectively, with an ellipsoid area of 1.578 (Z) mm×0.097 (X) mm×0.100 (Y) mm. Further research is required to make effective use of the CRes identified in this study for clinical applications.

Three-dimensional positions of the center of resistance of the maxillary canine distal movement under orthodontic force loading

“…where AVG is the average, t is the t-value, SD is the standard deviation, and n is the number of samples 15) .…”

“…For this purpose, it will be important to create individualized two-and three-dimensional analytical models, for which comprehensive information on the CRes will be required. We previously reported the CRes of the maxillary first molar against the occlusal force applied to the crown of the molar at a loading point that produced tooth movement without tipping or rotation 15) . A position of a CRes depends on a direction of a force, and changes by shape of its tooth root.…”