Orthodontic Displacement and Stress Assessment: A Finite Element Analysis

Abstract

Aim:The aim of the study was to analyze the stress distribution and displacement of palatally impacted maxillary canine and its adjacent teeth (lateral incisor and first premolar) when orthodontic extrusion forces were applied on the impacted canine. Materials and methods:A three-dimensional finite element model of a maxilla containing a palatally impacted canine was constructed. Forces of 50, 70, and 100 gm were loaded on the impacted tooth.Results: There was a steady increase in the initial rate of displacement and the von Mises stress of the periodontal ligament (PDL) in the three teeth when the magnitude of the force that was applied onto the canine increased. The initial rate of displacement was more in the first premolar tooth as compared with lateral incisor and the impacted teeth. Conclusion:The rate of displacement in relation to the first premolar was more as compared with the lateral incisor, indicating that the first premolars had the maximum anchor loss. 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.Clinical significance: The use of finite element analysis (FEA) can help us to understand how biological tissues (tooth, PDL, alveolar bone, etc.) would respond to the orthodontic forces that are being applied on them. Individual virtual models customized to the patient's clinical situation can be obtained and tested for various orthodontic force applications.

The Center of Resistance of an Impacted Maxillary Canine: A Finite Element Analysis

“…Woo et al [23] used a laser reflection technique to find the COR of the maxillary anterior teeth. However, most studies [14][15][16][17][18][19][20] have used the FEM. The advantage of the FEM is that the model setting is free and that even complex shapes can be modeled.…”

“…Previous studies [18][19][20] on the COR of impacted teeth have been conducted on impacted teeth with exposed crowns. Prasad et al [18] used the FEM to calculate the von Mises stress of the impacted canine and surrounding teeth when a palatally impacted canine with an exposed crown was pulled from a 0.019 × 0.025 stainless steel archwire. In addition, the side effects that may occur in surrounding teeth were predicted using the FEM.…”

“…There are several methods [21][22][23] for calculating the COR of the tooth, but the FEM is widely used [14][15][16][17][18][19][20]. The FEM is a method of analyzing the stress distribution of an object against external force after creating an accurate model of the anatomical structure and physical properties of the object using a computer [16,24,25].…”