Finite Element Modeling for Orthodontic Biomechanical Simulation Based on Reverse Engineering: A Case Study

Abstract

In order to improve the validity and feasibility of the solid model of oral tissue, a new method is provided based on reverse engineering. Biomechanical simulation with FEM is an important technique for orthodontic force analysis and evaluation, as well as treatment design. As the base of FEM simulation, the solid geometrical models of oral tissue including tooth, Periodontal Ligament (PDL) and alveolar bone are difficult to construct through conventional solid modeling methods because the oral models are very complicated in geometry and topology which are generally represented as triangular meshes. But in many cases, solid model is necessary for FEM performing. So how to construct the solid model of oral tissue with good quality and efficiency is a problem should be faced and solved in orthodontic biomechanical simulation. Aiming at this problem, reverse engineering modeling is adopt to transfer triangular meshes to four-sides surface model and together with techniques of medical image processing, three dimensional triangular meshes calculating, surface fitting and solid modeling, the solid geometrical model of oral cavity for FEM analysis is constructed from CT (computerized tomography) images. With a simulation case of rat molar movement test, the whole procedure of solid modeling based on reverse engineering and some main techniques are presented and the validity and feasibility are proved also by the simulation results.

Biomechanical Effects of Different Auxiliary-Aligner Designs for the Extrusion of an Upper Central Incisor: A Finite Element Analysis

“…The PDL was simplified, neglecting its variable thickness, and modelled as a 0.2 mm uniform thick layer [16, 21]. A shell of 0.2 mm thickness was added to the external surface of each tooth; the shell volume was then subtracted from the alveolar bone to define the PDL volume [22].…”

Computer aided modelling to simulate the biomechanical behaviour of customised orthodontic removable appliances

“…For this reason, the PDL has been geometrically created by detecting the intersection area between bone and tooth models to which a 0.2 mm thick shell has been added. The volume shell is then subtracted from the alveolar bone in order to define the PDL volume [24]. Finally, the bone modelling process has been performed by taking into account the division between cancellous and cortical bone, which has a mean thickness value of 0.25 mm around the teeth socket [25].…”

Biomechanical Effects of Different Auxiliary–Aligner Designs on the Rotation of an Upper Canine: A Finite Element Analysis of a Specific Patient

“…For this reason, the PDLs were manually created by adding a 0.2mm shell to the area at the intersection between the bone and tooth models. The shell volume was then subtracted from the alveolar bone to obtain the PDL volume [29].…”