Angle Class II malocclusions may present morphologic deviations originated from the maxilla, mandible, or both. Since its reintroduction by Pancherz, the Herbst appliance has demonstrated effectiveness in the management of patients with mandibular deficiency. Because of the intermaxillary anchorage, the action of mandibular advancement provokes simultaneous reaction of maxillary restriction, similar to high-pull headgear. This aimed of this report is to compare two cases treated in two phases. In the first interceptive phase, the transverse problem was corrected by rapid maxillary expansion, which was followed by a Herbst appliance for mandibular advancement; in the second corrective phase, the cases were finished with fixed appliances. Although Herbst appliances were used in both patients, one patient with maxillary protrusion and another with mandibular deficiency, their use targeted different types of skeletal discrepancies. This difference allowed for the comparison of treatment effects, and although both patients had their malocclusion corrected, it seems reasonable to conclude that the final outcome was more favorable for the patient with maxillary protrusion. ORTHODONTICS (CHIC) 2012;13:e188–e207.
Key words: Herbst appliance, malocclusion, mandibular incisor extraction, skeletal Class II