Skeletal Class II division 1 malocclusion treated with twin-block appliance

Abstract

A 10-year-old female presented with a skeletal Class II relation with 7 mm of overjet, 40% overbite, and bilateral posterior lingual crossbite. Two-phase therapy was planned to correct Class II skeletal relation, overjet, overbite, and to achieve lip competency. Phase I therapy was done with twin-block appliance to advance the retrognathic mandible. Phase II therapy was accomplished with fixed appliance for arch coordination to correct minor displacement and to finalize occlusion. Posttreatment, skeletal Class I relation was achieved. Incisors' inclination was improved, and ideal overjet and overbite with bilateral class I molar relationship was achieved. As the mandible advanced, lip competency, facial convexity, and mentolabial sulcus improved.