The force-distance properties of attracting magnetic attachments for tooth movement in combination with clear sequential aligners

Editorial summary

This laboratory study evaluated magnetic attachments proposed for use with clear orthodontic aligners. Twenty-nine rectangular neodymium–iron–boron magnet configurations were assessed by measuring attraction as paired magnets were progressively separated. Magnet dimensions strongly influenced force: larger pole faces and longer magnetic axes produced greater attraction, while force fell rapidly with separation and was generally small beyond approximately 2 mm. The experiments identify configurations that may provide useful force levels for orthodontic applications. They characterize the magnets themselves and do not demonstrate the effectiveness of a completed treatment in patients.