This orthodontic space closure technique has been used since 1940. A loop is a spring or spiral made on an arch
wire and its objective is to move teeth in an individual or collective manner. Loops must exert continuous but
controlled force, with a safety margin that auto limits its function after some time and should not permanently
damage teeth or supporting tissues.
A base and two vertical or longitudinal arms constitute loops.
a) The base can have a straight or curved form.
b) The arms. The arm extension determines the magnitude of the force that is exerted by the loop; the larger
the loop, the less force is exerted. The height oscillates between five and seven millimeters. A two millimeter increase in height diminishes the force 50%. A limitation of the height of the loop is the depth of the buccal
fold, because we can lesion the fold if the loop is too high.