 Patients will have a follow-up every two months during 6 to 12 months until the Class I occlusion is achieved. A lateral cephalogram and a dental silicon impression will be performed at the beginning T0 and at the end of the treatment T1 in order to evaluate cephalometric measurement changes, ANB, overjet and canine and molar class evolutions. The data collected at the beginning and at the end of the treatment will be analyzed and compared aware from patient, treatment and time, in order to assess the Twicare noninferiority compared to the Herbst and to confirm the superiority of these two appliances versus observation. We will study, in parallel, the nasal ventilator function as well as comfort, compliance, tolerance and acceptability of the device via an auto-questionnaire. 