Three-Dimensional Finite Element Comparative Assessment Of The Maxillary First Molar Distalization With Four Kinds Of Intro-oral Appliance

ObjectiveThe aim of this study was to use the finite element method to simulate the distal movement, tipping and rotation of the maxillary first molar with four kinds of intra - oral molar distalization techniques, including Vlock, Jones jig , Pendulum and Pepelling magnets, to support a experiment basic for improving the clinical operating system, selecting and controlling anchroge , and to support a biomechanical basic for applying orthodontic forces in clinic.MethodThe three - dimensional finite element model of the maxillary first molar consisted of 3334 nodes and 2698 isoparametric eight - node solid elements. The model was designed to dissect the periodontal lig-ment, root and alveolar bone separately. Six point including A, B, C, D, E, F was selected to evaluating distal movement , tipping and rotation of the maxillary first molar when an anterior force of 1N was applied at the center of the buccal or lingual crown surface of the tooth.Result1. The movement of the six point were different in the five situa-tion. Comparaed the five condition , when the force applied on both buccal and lingual of the crown , the distance of movement was the biggest 4. 635E -05 with tipping and rotation in the 5nd condition.2. when the force was applied at the center of the lingual crown surface of the maxillary first molar, the crown rotated from lingul to the missal ; when the force was applied at the center of the buccal crown surface of the maxillary first molar , the crown rotated from buccal to missal.3. Pendulum appliance can result to the biggest tipping . Jones jig appliance can result to a smaller tipping.Conclusion1. When the force was applied at the both buccal and lingal, the distance of movement is the biggest with bigger tiopping and rotation.2. Comparaed buccal to lingal, the rotation tipping and distance in buccal condition are smaller than those of in lingal.3. Pendulum appliance can result to the biggest tipping . Jones jig appliance can result to a smaller tipping.4. Pendulum appliance can result to the biggest rotation. . Jones jig appliance can result to a smaller rotation.5. When IN force was applied at the different point of buccal crown surface of FEM of the maxillary first molar, with the same horizon the more the force point near to the center, the more the tooth are clined to body movement.6. In all the conditions, Jones jig is the best for maxillary first molar distalization with body movement...