A prospective comparison clinical study was designed to evaluate the effectiveness of the open bite bionator and the upper posterior bite plane with a crib in the early treatment of skeletal anterior open bite . The bite plane /C sample (G1) included 20 subjects, 11 girls and 9 boys. The average age was 8.6 Years . The OBB sample (G2) contained 20 subjects, 8 girls and 12 boys. The average age was 8.8 years . Lateral cephalograms were analyzed at T1 and T2 (T2 : after one year of treatment ) to study the changes of the hard and soft tissues by using a special program known as ADOrthoA.