Clinical application of magnets in orthodontics and biological implications: a review

Over the last decade magnets have been used in orthodontic and dentofacial orthopaedics and attempts have been made to evaluate the biological implications of magnets and magnetic fields during clinical application. This review aims to indicate the advantages and disadvantages of magnets in orthodontics and dentofacial orthopaedics over traditional techniques, and update related clinical experiences. The treatment of impacted teeth and Class II malocclusions by means of magnetic force is favoured and the correction of Class III and open bite malocclusions involving the use of magnets also appears promising. The advantages of magnets over traditional force delivery systems are: frictionless mechanics, when the magnets are in attractive configuration; predictable force levels, no force decay over time and less patient co-operation. However, the size of the magnets can increase the bulk of the appliance and three-dimensional control is limited when the magnets are in a repulsive configuration. In addition magnets used in vivo require a coating to prevent corrosion and the possible side effects of corrosive products.