Stress Distribution in the Nasomaxillary Complex Following Application of Orthopaedic Headgear Forces- A 3-Dimensional Fem Study

Abstract

BACKGROUND Extraoral force has been in use in orthodontics since Cellier introduced it in early 1800s. Like many other treatment modalities, interest in headgears and the understanding of its probable effect has varied over the years. From only dental changes to skeletal changes affecting the cranial base structures as well, all have been attributed to headgear use at various times. At present, it is well established that headgears have a retarding effect on the growth and development of maxilla. However, the exact biomechanical effect of different force directions on the sutural response is still under consideration. MATERIALS AND METHODS The present study was undertaken to examine the effect of posteriorly directed headgear forces on the various nasomaxillary sutures. FEM model was created having 236685 elements and 56052 nodes and 1 Kgf force was applied at-30 0 , 0 0 , 30 0 , 52.4 0 and 60 0 to the functional occlusal plane.