Aim: To evaluate the dentoskeletal effects produced by Fränkel-2 (FR-2) appliance during the treatment of patients with Class II malocclusion by mandibular retrusion and to verify the long-term stability of these changes.
Materials and methods: Pre-treatment, post-treatment and long-term serial cephalograms (at least 10 years after the end of treatment) of patients treated with FR-2 were compared with data obtained from untreated controls. To be included in the study, patients and controls had to exhibit Class II malocclusion caused by short mandibular body. Lateral cephalograms were analysed with a specific tracing regimen in both groups. Summary measures for the initial cephalometric values and increments of changes between visits were calculated.
Results: Compared to controls, the FR-2 treatment produced a significant decrease in the ANB angle that improved the skeletal intermaxillary and occlusal relationship. At long-term follow- up, the FR-2 group showed further improvements of skeletal intermaxillary and occlusal relationship, therefore the changes observed during treatment showed no compensatory decline or rebound.
Conclusion: FR-2 treatment, in conjunction with a period of post-functional fixed appliance therapy designed to perfect the occlusion, can produce a long-lasting improvement of the skeletal Class II malocclusions with little skeletal correction and significant incisor compensation.