THE PERFORMANCE OF BONDED MAGNETS USED IN THE TREATMENT OF ANTERIOR OPEN BITE

This investigation examined the magnetic flux and repulsive force of n eodymium-iron-boron (Nd-Fe-B) magnets based on Nd2Fe14B with acrylic c oatings in different orientations. The flux was measured with a Hail p robe and the force measured by electronic scales with the magnets moun ted on a laboratory jack. Results show that there were no magnetic los ses after embedding the magnets in acrylic bite-blocks, although there were significant flux losses when the magnet blocks were directly hea ted. The alignment of the magnets over each other was of the utmost im portance and significantly affected the repulsive force between the ma gnets. When the magnets were mounted in an articulator to simulate jaw movement, the force levels between the magnets was further reduced as a result of the effects of the rotation of the articulator. It is con cluded that Nd-Fe-B type magnets embedded in acrylic can be used to gi ve predictable repulsive forces in the mouth. The dramatic reduction i n force levels when the magnets are not in optimal alignment, however, makes their effectiveness in aiding intrusion of teeth doubtful.