Magnetic force in orthodontics.

Abstract

apy. The present study shows that small permanent magnetic devices offer a new, innovative, and biologically safe approach in generating intermaxillary, intramaxillary and extraoral force. Present methods of treatment, especially with elastics, may be satisfactory, but problems do exist. For example, lack of cooperation on the part of the patient can result in either failure or compromise of treatment objectives. Polygraph studies at Loyola University emphasized this lack of cooperation by showing that adults as well as children were often not reliable in using elastics is $ in fact, those patients were carefully selected prior to treatment for good motivation and were usually thought by their orthodontists to be cooperative. Magnets can eliminate this problem of the patient’s cooperation, since they are totally operator-controlled. Continuous application of force results in decreasing treatment time. Lengthy treatment can produce periodontal disturbances, root resorption, and caries. A shorter treatment time may make orthodontic therapy available to a wider spectrum of the population. Permanent magnets can also provide better directional force control. For example, with mandibular opening, when magnets are used for intermaxillary force, the air gap increases, and the vertical component of the force vector decreases rapidly, first as the square and then as the cube of the distance. This is an advantage over the use of elastics, with which the vertical force vector increases upon mandibular opening, thus producing an undesirable increase in the cant of the occlusal plane. Magnets can also be used for continuous high-deflection, low-rate force with precise control. Proper momentto-force ratios can be achieved, and tipping, root translation, and root torquing are also Possible. It is a total force system with a favorable benefit-to-risk ratio. Intermaxillary elastics also account for the loosening of bands because of the large vertical vector of force. On the other hand, magnetic devices generate a more horizontal force vector, which does not tend to unseat bands. Obviously, loose bands require much time for re-cementation, and also increase the patient’s susceptibility to caries. Talc and starch may have been used as dusting powders on orthodontic elastics, and, as reports in the medical literature have indicated for some time, these agents, in a medical situation, may be related to granulomatosis, pulmonary talcosis, immunogenic reactions, md, possibly, carcinoma. 3~8 Some of these reactions demonstrate a clinical latency so that they may not appear for many years after the patient’s initial exposure. In addition,