Toward patient-specific prediction of orthodontic tooth movement (OTM): A Maxwell-based phenomenological approach

Tooth displacement in the mesiodistal direction over a 12-week period is predicted using a two degrees of freedom Maxwell model under constant load ranging from 18g to 240g. The viscoelastic behavior of the alveolar bone is represented by capturing both its instantaneous elastic response and its time dependent remodeling behavior. The bone stiffness is derived from patient-specific medical imaging, while the tooth kinetic displacement, represented by the viscosity parameter, was calibrated using experimental literature data reported for canine retraction. The predicted numerical results provide interpatient variability boundaries of tooth displacement, within which the experimental and approximate tooth displacements are located. Next, a three-degrees of freedom Maxwell model accounting for the orthodontic wire was employed to estimate the force relaxation occurring in the wire during treatment. This model serves as the starting point for development of patient-specific forecasts of orthodontic tooth movement.