Comparison of the effects of forsus FRD and herbst IV appliances in late skeletal class II cases due to deficiency of mandibular growth using cephalometric techniques

The aim of this study was to compare cephalometrically the effectiveness of two commonly used fixed functional appliances named Herbst IV and Forsus FRD in Class II cases with mandibular deficiency requiring mandibular protrusion. Thirty-two patients of which referred to our clinics were selected for the study (10 boys, 22 girls). Mean age of the patients was 14.7 years. Forsus FRD fixed functional appliance was applied to 16 patients, and Herbst IV fixed functional appliance to the other 16. Fixed functional appliances were kept activated in all cases until incisors came to edge-to-edge contact and hold in place for 7 months. Lateral cephalometric films were obtained before and after fixed functional appliances in order to evaluate the changes occurring during the treatment with these fixed functional appliances. Subsequently, the data was evaluated with paired t-test, independent samples t-test in 95% confidence interval. Both Herbst IV and Forsus FRD appliance were found effective in the correction of molar relationship and the elimination of overjet according to the data. Herbst IV was found slightly more effective than Forsus FRD in some skeletal measurements. As a result, both Herbst IV and Forsus FRD fixed functional appliances; Herbst IV appliance being more effective skeletally; are effective methods in the correction of molar relationship and overjet in Class II cases due to mandibular deficiency.