[Evaluation of three dimensional orthodontic force produced by magnet of fix appliance].

Purpose: To analyze the feature and magnitude of three dimensional orthodontic force produced by the magnet of fix appliance.

Methods: Forces detected by universal fatigue test system included the attractive and repulsive,the inclined and rotated orthodontic forces of two magnets in different air gaps, and the integrated inclined and rotated orthodontic forces of two magnets and NiTi wire.

Results: The attractive and repulsive forces of two magnets were 4.

[Evaluating the integrated force induced by high quality magnet and elastics in orthodontic fixed appliance].

Purpose: To investigate the stability and effective working distance of integrated forces induced by high quality magnet and elastics in orthodontic fixed appliance.

Methods: N48 NdFeB magnets resembling brackets in size and volume were combined with 1/8, 3/16, 1/4, and 3/8 inch orthodontic elastics respectively to induce integrated forces that had super-long working distance. Magnetic, elastic, and integrated forces were tested by universal material test system and curves of the forces were draw.