Finite Element Analysis of Maxillary Anterior Dentition During Retraction With Varying Level of Bone Support

This study is being carried out to evaluate and compare the stress along the root surfaces of anterior maxillary dentition during retraction in labial and lingual mechanics with varying level of bone support. Eight three-dimensional finite element models (FEM) were created with normal periodontium and different levels of alveolar bone loss; four with labial brackets and four with lingual brackets. Sliding mechanics were simulated as en-masse retraction of the anterior dentition. The equivalent stresses along the roots of six anterior maxillary teeth were measured in all the models. Equivalent stresses generated at the root surfaces of central incisors are always higher in labial technique and of canines are always higher in lingual technique, suggesting the increased vulnerability toward root resorption in both cases. Stresses at the root apices of all the teeth are increasing progressively when the bone loss is progressively more than 2 mm in labial technique. In labial technique, the stresses at the root apices of all the teeth are increasing progressively when the bone loss is progressively more than 2 mm. In Lingual technique, equivalent stresses generated at the root surfaces of canines are more than central and lateral incisors irrespective of the alveolar bone loss, suggesting increased susceptibility to root resorption.