Mousetrap appliance is an effective treatment modality for anterior open bite that utilizes implants inserted into the anterior palate and brings about open bite correction by intruding the maxillary molars. This is a finite element study that assesses the stress contours at the bone mini-screw interface, when the maxillary molars are intruded by a mousetrap appliance. Materials and Methods: A finite element model of the maxilla and the mousetrap appliance made of 288332 elements and 64771 nodes was generated using software tools like MIMICS and HYPERMESH. A simulated force of 100 grams was applied to the maxillary molar through the appliance and the stress contours were assessed. Results: In the cortical bone Von-mises stress at the bone mini-screw interface was around 13.2MPa whereas in the cancellous bone it was around 0.198MPa. Conclusion: It is therefore concluded that the mousetrap appliance which exerts a force within the range of recommended force for molar intrusion generates stress contours at the bone mini-screw interface in cortical as well as cancellous bone. More stress is generated in the cortical bone.