Simulation of a three-dimensional craniofacial structure under the application of orthodontic loads

The aim of this study was to develop a three-dimensional model of a patient’s craniofacial structure to be analysed using the finite element method in order to estimate the forces required to carry out a dental positioning’s correction. The three-dimensional model was composed by several anatomical structures, namely the teeth, the periodontal ligaments, and the trabecular and cortical bones, which were modelled with the aid of computed tomography cone beam images. The tomographic images were analysed and reconstructed using the 3D Slicer software, while the assembly of the anatomical structures modelled, as well as the contact surfaces between contiguous parts, was defined in computer-aided design software. Bone remodelling and the occurrence of tissue’s injuries were considered during the numerical simulations carried out. By imposing displacements to each tooth, it was possible to calculate the orthodontic loads needed to carry out dental correction (reaction forces), as well as the distributions of stresses and deformations inherent to the clinical treatment, allowing to obtain a craniofacial structure capable of simulating the dental movements of upper and lower arches with anatomical realism. In addition, this methodology constitutes a personalised dental medicine that could lead to the development of highly customised orthodontic appliances where different mechanical loads could be applied individually to each tooth to achieve the foreseen dental correction.