Canine retraction

Abstract

Distal wires are formed on the plaster casts so that the free ends rest on the buccal tubes of the banded maxillary permanent first molars. This greatly increases the stability of the removable appliance in the mouth. Wires are also bent to contact the mesial surfaces of the premolars to prevent them from drifting mesially when first premolars have been extracted in either the maxillary or the mandibular arch. Springs move the canines distally into the extraction areas in either one or both arches, as has been described. They may be moved entirely back to the second premolars in some cases or only part of the way back, depending upon the cephalometric appraisal and the operator's judgment. This, then, leaves the four incisors as an island to be moved back as a unit after bands and appliances have been placed on the teeth. Each maxillary removable appliance generally has a flat bite plane or ridge for the lower incisors to occlude against. The springs on the mandibular removable appliance may be formed in the same manner as on the maxillary appliance, and mandibular appliances must have occlusal rests on the permanent first molars. At times in either the maxillary or mandibular appliance it may be necessary to have only unilateral springs. Patients almost always apply extraoral traction during this phase of treatment. These appliances are never referred to as “bite plates” to the patients but, rather, as removable appliances, since that is what they are—tooth-moving appliances.