Evaluation of Stress Distribution of Maxillary Anterior Segment during en Masse Retraction Using Posterior Mini Screw: A Finite Element Study oleh Meer Juned Ali, Amit Bhardwaj, Mohammad Shoyab Khan, Farhan Alwadei, Khalid Gufran, Abdullah Saad Alqahtani, Nasser Raqe Alqhtani, Mohammed Alasqah, Abdulaziz Mohammad Alsakr, Rawda Omar Alghabban