Cephalometric Comparison of a Modified Bionator (Farmand Appliance) and Twin-Block Appliance in Treatment of Skeletal Cl II Malocclusion

background and aim: functional appliances with various designs have been introduced in the treatment of Class II malocclusions. The aim of this study was to evaluate dentoskeletal effects of a modified bionator (FA) and Twin Block (TB) functional appliance in treatment of skeletal Class II malocclusion.Method and material: in this retrospective study ۳۰ treated cl II patients with overjet greater than ۴mm have been selected from each of two private offices .in each office either FA or TB were used. Pre-treatment and post-treatment lateral cephalograms were digitized and traced with Dolphin Imaging software. ANCOVA and paired T test were used for analysis with SPSS software (۱۹).Results: FA group consisted of ۱۷ girls and ۱۳ boys(mean age: ۹.۵۳± ۱.۱), TB group consisted of ۱۲ boys and ۱۸ girls(mean age: ۱۰.۲۶ ±.۹۴۴ ) .ANB angle and overjet were reduced significantly in both groups. (p=.۰۰۰) Mandibular body length demonstrated a significant increase in both groups( ۳.۰۶±۴.۹۸mm with TB and ۳.۰۳±۵.۵۲mm with FA ). In Both appliances significant retrusion of upper lip occurred as a result of decrease in overjet (TB=۰۰۲, FA=.۰۰۰). No statistical significant difference were found between two appliances.Conclusions: Treatment with both appliances resulted in correction of Class II discrepancy, reduction of overjet, and retrusion of upper lip. No significant dento-skeletal differences were observed between the ۲ appliances.

Keywords:

angle cl II malocclusion , activator appliances , Cephalometry , Treatment