The efficiency of correction of Class II malocclusion, using functional appliances have been reported in the literature some time ago. Several studies have showed how functional orthopedic appliances act on bone, muscle, and dental structures of patients who are at stages prior to the pubertal growth peak. Functional appliances take advantage of the natural forces of growth and development which achieves a normal function of the stomatognathic system that ensures adequate chewing, swallowing, speech, aesthetics and improving patient’s self-esteem at early age. The purpose of this case report is to show how satisfactory results are achieved with the treatment of Class II division 1 malocclusion in young patients using a functional appliance as Dr. Balters Bionator. Also to present the positive facial, dental and cephalometric changes, which were the result of proper diagnosis, proper selection of the appliance and excellent cooperation of the patient.