The intrusion arch is inserted into the molar tubes with the pre-activated 30° V-bends 2-3 mm mesial to the molar tubes so that the wire lies passively on the vestibular sulcus. Activation is accomplished by bringing it occlusal and tying it to the anterior segment attached to the four incisors. An intrusive force of 40 – 50 grams is applied on the incisors while, at the same time, the molars and/or the buccal segment undergo a reciprocal extrusive force and a distal crown moment. This moment can help in correcting edge to edge class II to class I molar relationship.
Indications:
Incisor intrusion
Simultaneous Class II molar correction
Incisor flaring
Correction of a minor open bite (Incisor Extrusion)
Correction of anterior occlusal cant
Preventing the side effects associated with canine retraction
