Treatment of Class II Malocclusion With Excessive Overjet

Class II malocclusion with excessive overjet is one of the most common malocclusions among children and adolescents. The overall goal of the project is to analyze orthodontic treatment of Class II malocclusion with excessive overjet when the treatment is started in different ages and treated with removable and/or fixed appliance. Treatment initiated before the age of eleven is performed with a removable functional appliance, Headgear Activator (HGA). Treatment starting in early adolescence is performed with fixed orthodontic appliance (FA). The hypotheses are: * Treatment with HGA at the age of nine or eleven is effective. No spontaneous correction of the malocclusion is expected in the untreated control group. * Patient experience, treatment effect and cost-effectiveness are equivalent whether the treatment with HGA is initiated at the age of nine or eleven. * Treatment results, patient experience and treatment- and cost-effectiveness are equivalent whether treatment is initiated early with HGA or initiated in early adolescence with FA. * The treatment of Class II malocclusion with excessive overjet renders long-term treatment stability and patient satisfaction.