Treatment effects of R-appliance and Fränkel-2 in Class II division 1 malocclusions.

AIM: The purpose of this study was to compare the effects of a differently designed functional appliance (the R- appliance) with Fränkel-2. STUDY DESIGN: Twenty-seven patients (16 girls and 11 boys) with a mean age of 9.8 (SD 1.6) years were treated with the R-appliance for 15.4 (SD 0.4) months and twentyseven (15 girls and 12 boys) patients with a mean age of 9.1 (SD 1.1) years were treated with a Fränkel-2 appliance for 19 (SD 5.6) months. All patients had Class II division 1 malocclusions due to mandibular deficiency and all of them had prepubertal stages of skeletal development. Lateral cephalograms obtained at the beginning (T1) and at the end (T2) of the study were analysed. RESULTS: Paired t-tests showed that SNB significantly increased in both groups. The incisor mandibular plane angle (IMPA) was reduced in the R- appliance group by 2.2 (SD 4.9) degrees (P<0.03) but increased by 2.2 (SD 2.6) degrees (P<0.001) in the Fränkel-2 group. The SNA in the R-appliance group showed an increase of 0.2 (SD 2) degrees (P<0.6), while it was decreased by 0.4 (SD 0.5) degrees (P<0.6) in the Fränkel-2 group. CONCLUSIONS: Both treatment modalities were successful in moving the mandible forward. However, with the R-appliance, this was achieved without proclination of the lower incisors.

Evaluation of long-term effects in patients treated with Fränkel-2 appliance.

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.