Treatment Effects of R-Appliance and Bionator in Class II, Division I Malocclusion

Aim: The main goal of this study was to compare the effects of a differently designed functional appliance (R-appliance) with a bionator treated group in Class II Division I (C۱ II Div I) cases.Materials and Methods: ۲۲ patients (۱۲ girls, ۱۰ boys) treated with R-Appliance were selected as experimental group. Control group consisted of ۲۲ patients (۱۱ boys, ۱۱ girls) treated with a bionator. All of the patients had a C۱ II Div I malocclusion due to mandibular deficiency. Lateral cephalograms were analyzed at the beginning (T۱, T ۱) and the end of the study (T ۲, T ۲).Results: Paired T-test showed that SNB significantly increased in both groups. The same test revealed that IMPA was reduced in the R-appliances treated group by ۴.۵°±۳.۵° (P<۰.۰۰۱) but it was increased by ۱.۹°±۳.۹° (P<۰.۰۳) in the bionator group. Analysis utilizing T-test showed that the inter group difference of IMPA was statistically significant (P<۰.۰۱). SNA showed an increase of ۰.۱°±۱.۶° (P<۰.۹) in the R-appliance treated group; while, it was decreased for ۰.۴°±۰.۹° (P<۰.۱) in the bionator treated group. Conclusions: Both groups were successful in advancement of mandible; however, the R-appliance achieved this result without retroclination of the lower incisors.

کلیدواژه ها:

Functional therapy ، Mandibular deficiency ، Class II Div I ، Increased over jet ، Growth modification ، Lower incisor flaring ، Headgear effect