Early treatment of skeletal Class III open bite with the Tandem Appliance.

facial deficiency or true mandibular prognathism are difficult to manage nonsurgically, particularly when a hyperdivergent mandibular growth pattern creates an anterior open bite. For the past 25 years, early growth modification of midfacial deficiency with expansion and facemask therapy has been the standard treatment for Class III malocclusions.1,2 A disadvantage of this ap proach is that it alters both the anteroposterior and vertical planes; the desired downward and forward movement of the maxilla is often accompanied by downward and backward clockwise rotation of the mandible.3-8 Although such mandibular rotation is desirable in deep-bite cases with hypodivergent growth patterns, it is inappropriate for patients with anterior open bites and hyperdivergent growth patterns. The vertical dimension can be managed in hyperdivergent-growth patients by utilizing appliances with interocclusal acrylic, such as a bonded expander,9 bite blocks10,11 or the Tandem Appliance.12 This article describes the use of the Tandem Appliance in nonsurgical correction of skeletal Class III malocclusions with open bite.