Evaluation And Comparison Of The Magnitude Of Stresses Developed On The Maxillary Anterior Teeth Region Under Different Intrusive Forces Using One Implant System And Two Implant System- A Finite Element Study

Abstract

ABSTRACT

Correction of a deep bite is an important part of orthodontic treatment due to the potential deleterious effects on the temporomandibular joint, periodontal health and facial aesthetics. Mini screw implants are ideally suited for absolute intrusion because they make it possible to apply light continuous forces of known magnitudes without producing any reciprocal reactionary effect on posterior teeth.The purpose of this FEM study was to evaluate and compare the magnitude of stresses generated in the maxillary anterior teeth, periodontal ligament and alveolar bone during intrusion of six maxillary anterior teeth using different intrusive forces with mini-implants placed at strategic locations.

Methods:A 3-Dimensional geometric model of human maxilla was fabricated from the DENTASCAN of human skull. The geometric model of maxilla was then converted into 3-Dimensional FEM model using HYPERMESH software 13.0 version.  FEM models of brackets, arch wire, mini implant and coil spring were transferred to the FEM model of maxilla.  Two separate models were generated, one with mini implant in the midline of maxilla placed between central incisor roots and in second model the mini implant was placed between lateral incisor and canine roots on both sides. Mechanical properties of the materials were applied to the two models. Intrusive loads of different magnitudes were applied on the implants.

Results:Maximum stress was observed at the head of implant at the point of attachment with the intrusion spring. The total tooth deformation was found to be more with group I.

Conclusion: Stresses developed are less and distributed more evenly, when the point of force application is bilateral rather than a single source. Hence uses of bilateral implants are more efficient and less detrimental for the teeth and surrounding periodontium, during absolute en masse intrusion of the maxillary anterior teeth.

Keywords: biomechanics, finite element analysis, force, implant system