Early Correction of a Developing Skeletal Class III Malocclusion

This case report describes the treatment of a Japanese girl aged 11 years 10 months who had a severe Class III malocclusion with a concave facial profile. She presented hypodivergent skeletal pattern with a -4.0-mm anterior crossbite and a deep overbite. She also had facial asymmetry attributed partly to the lateral mandibular shift to avoid incisal interferences. The treatment plan included a monoblock appliance, rapid palatal expansion, and fixed edgewise appliances at the final stage. The monoblock appliance was used to redirect the growth of the mandible to a clockwise direction and simultaneously correct the incisal relationships along with fixed edgewise appliances. Good incisal relationships were achieved, and facial esthetics was greatly improved after 28 months of treatment. Stability of the treatment result was excellent in the 3-year 9-month follow-up at the age of 18.