Displacement and periodontal stress analysis on palatally impacted canine - A finite element analysis

ABSTRACT

Objective: The aim of the study was to analyze the displacement and stress pattern in periodontal ligament (PDL) of palatally impacted canines (PIC) lateral incisors (LI) and first premolars (FP) adjacent to the impacted teeth when different magnitudes of orthodontic extrusion forces were applied along with variation in the inclination of the impacted teeth. Methodology: A three-dimensional finite element model of a maxilla containing a palatally impacted canine was made with three different inclinations of the palatally impacted canine (model one, model two, and model three). Forces of 50, 70, and 100 g were loaded on the impacted tooth. Results: There was steady increase in the initial rate of displacement in the three teeth when the magnitude of the force that was applied on to the PIC increased. The initial rate of displacement was more in the FP tooth as compared to LI and the impacted teeth. The von Mises stress on the PDL varied along with the variation in the inclination of the impacted canine. Conclusion: The study showed that there was variation in the displacement and the stress distribution in the impacted canine when it was placed in different angulations. The rate of displacement of the impacted teeth reduced when the crown of the palatally impacted canines (PIC) was inclined more mesial. The use of minimal forces is ideal to extrude the impacted canines as observed from the study that the PDL stress increases with increase in the magnitude of force.