LAUSR

The purpose of this study was to compare the effect of a 4-bracket system including Alexander, Roth, MBT (Maxillary Transverse Bioadaptation), and Gianelly on the upper anterior tooth movement in sliding mechanics with the help of a 3-Dimensional (3D) Finite Element Method. METHODS Displacement, stress, strain, centre of rotation and resistance on the incise edge and apex of the maxillary central incisor were calculated when 100, 200, 300, 400grams of retraction force were applied. RESULTS The amount of incise edge displacement was 2.609×10-4mm 2.682×10-4mm 2.875×10-4mm and 2.881×10-4mm in Alexander, Gianelly, Roth and MBT respectively with 100gr of retraction force. The value of apex root movement was 3.485×10-4mm 3.547×10-4mm 3.852×10-4mm and 3.864×10-4mm in Alexander, Gianelly, Roth and MBT respectively with 400g of retraction force. CONCLUSIONS The MBT system had the maximum apex root and incisal edge movement in all 100, 200, 300, 400grams of retraction force. The Alexander system had the lowest apex and incisal edge movement in all retraction forces.