Aim: This article describes the treatment of a patient with a Class II malocclusion and bilaterally impacted canines using a Jasper jumper appliance. An unfavorable side effect of the appliance became a benefit as part of the treatment. Methods: Treatment objectives were to erupt the impacted canines, expand the decreased intermolar width, and obtain a well-balanced profile, with a Class I occlusion. The widening effect of this appliance on the maxillary molars was expected to help increase the intermolar distance. Results: Favorable changes were noted, both in the occlusion and in the profile. Class I canine and molar relationships with ideal overjet and overbite were achieved. Overbite and overjet were decreased by a combination of retrusion and extrusion of the maxillary incisors, and protrusion and intrusion of the mandibular incisors. The maxillary canines were erupted successfully, with healthy gingival tissue. The crossbite in the right posterior segment was corrected as a result of the increase in the intermolar distance. Conclusion: The results gained were primarily dentoalveolar, rather than skeletal. There has been an improvement in the occlusion and esthetics. World J Orthod 2006;7:399–405.