7 Effect of orthodontic appliances on magnetic resonance images

Abstract

We examined the metallic artifacts created in magnetic resonance images (MRI) when various orthodontic appliances were placed on study models. We used steel, ceramic and resin brackets, steel, NiTi, heat-activated NiTi and Beta-Ti orthodontic wires, and steel and elastic ligature wires. Several sequences of images were taken with a 1.5 tesla super-conductive MRI machine. Adapted steel brackets, steel wire and steel ligatures produced the largest metallic artifacts in the images. Steel brackets alone produced large metallic artifacts. Ceramic brackets and Ti materials did not produce large metallic artifacts. We concluded that orthodontists should not use steel orthodontic appliances for patients who expect to have MRI of the head and neck region.