Goal of research is whether orthodontic bone remodelling can be predicted using load adaptive bone remodelling theories developed in orthopaedic biomechanics where strain energy density, SED, is a mechanical stimulus for the bone and it is associated with bone density changes. The hypothesis is that the tooth is “hanging” in the fibrous PDL and orthodontic loading would reduce the loading in the fibres on the side to which the tooth is pushed and increase the loading in the fibres on the other side. In the process the alveolar bone and the periodontal ligament react mechanically and biologically to the loading. The focus in research was on the mechanics and the phenomenological aspect of biology described with Finite Element Method. Chewing force represents daily loading in the mouth and referent value of stimulus. 3D model was developed from CT scans from a patient to whom orthodontic treatment was recommended and it was made in the software Mimics, which reads bone density from CT images. 3D model was imported in Marc Mentat where different orthodontic loading were analysed. Last step is the implementation of bone remodelling algorithm made in the programming language Fortran into Marc Mentat by special user subroutine. The proposed description of bone remodelling initiation is able to indicate underloading and overloading condition, which leads to bone resorption and formation mimicking biological response. The main contribution is the development of a numerical model of bone remodelling initiation which includes influence of chewing force, fibrous periodontal ligament, patient-specific geometry and putting SED as mechanical stimulus.