Comparison the effects of activator and miniplate anchored forsus appliance in treatment of mandibular deficiency

The aim of this study is to compare the functional treatment results obtained by miniplate anchored Forsus FRD and conventional activator appliance. The miniplate anchored Forsus FRD group was designed prospectively and the activator group was selected retrospectively. The first group consisted of 18 individuals (mean age 13.52 ± 1.23) treated with miniplate anchored Forsus FRD appliance. The second group consisted of 18 individuals (mean age 11.72 ± 1.36) treated with activator appliance. In the first group, following the leveling stage, 0.017x0,025 inches stainless steel archwire was inserted and miniplates were placed bilaterally in mandibular symphysis area. Forsus FRD appliances were attached between miniplates and 1st molar headgear tubes. In the second group, the bite record was registered with wax in edge to edge relation of insicors and than activator was applied. The functional treatment lasted 10,72 ± 1,71 months in the first group and 13,78 ± 5,17 months in the second group which was continued until Class I molar relationship was obtained in both groups. To evaluate the treatment effects, lateral cephalometric films were taken before functional treatment (T1) and at the end of the functional treatment (T2). Mann Whitney U and Wilcoxon tests were used for statistical evaluation. According to the results of our study, the mandibular growth was stimulated in both groups whereas increase ineffective mandibular length was greater in the second group. In the first group, distalization and intrusion of maxillary molars and extrusion and retrusion of maxillary incisors were observed. In the second group, there were no significant changes in the position of maxillary molars and incisors, whereas intrusion and protrusion were seen in mandibular incisors. The overjet correction obtained was more than half of skeletal origin in the activator group, whereas the miniplate anchored Forsus FRD group demonsrated more dental correction. Overbite and overjet decreased and soft tissue profile improved in both groups, improvement was achieved by combination of skeletal, dentoalveolar and soft tissue changes in the treatment of Class II malocclusion due to mandibular retrognathia during growth development period with both treatment methods.