Effects of Static and Pulsed Electromagnetic Fields on Orthodontic Tooth Movement: An Animal Study

Background: Electromagnetic field therapy has emerged as a non-invasive and effective modality for enhancing bone quality and quantity during the healing process. This study aims to determine the effects of pulsed electromagnetic fields (PEMF) and static magnetic fields (SMF) of the same intensity and duration on orthodontic tooth movement. Methods: Forty-five male albino rabbits were randomly assigned to three groups (15 rabbits per group): control group, PEMF group and SMF group. The PEMF group was exposed to a pulsed electromagnetic field generated by a commercially available portable device (square waveform, 120 Gauss intensity, 9.6 Hz frequency, with 1 hour of daily exposure for 3 weeks). The SMF group was subjected to a static magnetic field generated by neodymium iron boron permanent magnets (120 Gauss intensity, with 1 hour of daily exposure for 3 weeks). Five rabbits from each group were sacrificed at the end of each week for analysis. Result: The rate of tooth movement, amount of new bone formation and the count and activity of osteoblasts and osteoclasts were significantly higher in the PEMF group as compared to the control group. The SMF group also exhibited significantly higher results in most of the measured variables over the 3 weeks relative to the control group, although the outcomes were less pronounced than those observed in the PEMF group.