The aim of this study was to evaluate the dentofacial effects of Monoblock and Twin Force appliances used in Class II Division 1 cases.
Twenty patients who were referred to our clinics were selected for our study. These patients were randomly allocated to each of the two functional appliance groups. Of these, 10 were treated with Monoblock and the remaining 10 were treated with Twin Force appliances. The inclusion criteria were as follows: Class II division 1 malocclusion, retrognathic mandible, peak growth period, normal or low-angle growth pattern and increased overjet. Pre-treatment and posttreatment cephalograms were obtained to evaluate the dentofacial changes. The intra-group comparisons were determined with paired samples t-test, while the inter-group comparisons were determined with students t-test at the significance level of p < 0.05.
It was revealed both appliances increased mandibular growth, helped enhancement of the effective mandibular length and had a restricting growth effect on the maxilla.
While the Monoblock appliance was more advantageous in cases where the skeletal effect ratio was higher because the dental effects of the Twin Force appliance were greater than that of the Monoblock appliance, the Twin Force appliance was a more effective choice in case of lack of cooperative operation of the patient's mobile functional appliance.