3D Tooth Modeling for Orthodontic Assessment

Use of three-dimensional (3D) imaging data from cone beam computed tomography (CBCT) together with the mathematical concept of axes of inertia permits characterization of three-dimensional (3D) geometry for discrete anatomical objects including teeth. A study was conducted to investigate this concept. With Institutional Review Board approval, the “axes of inertia” concept was applied to image data sets from a cohort of 205 subjects. Following analysis, this cohort was found to fit into 18 categories. Starting with a calculation based on tooth axes of inertia and dental arches morphology, 3D images were related to the 18 categories. Teeth and the dental arches were integrated into a 3D architectural model of the visceral skull using Cartesian coordinates of 14 anatomic landmarks. Axes of inertia are a mathematical tool for 3D modeling of discrete anatomical objects such as teeth, using CBCT image data bases.