“…Inclusion criteria : age ranged from 8 years to 11 years, cervical vertebrae maturation index (CVMI 2 and 3) identi ed on the lateral cephalometric radiograph, (29,39) angle Class III molar relation. (29) Skeletal class III ANB ranged (-4) -(0), Wits appraisal ranged (0) -(-5), (27) ,reversed over jet (-6) -(-1), good oral hygiene and healthy periodontal condition (40) , normal vertical growth pattern (SN/MP angle 28˚-38˚) (41) Exclusion criteria were: patients with a discrepancy between centric relation and maximum intercuspation, (42) patients who underwent previous orthodontic treatment, (25,43) patients receiving drug therapy that may affect orthodontic tooth movement, (17) and had congenitally missing teeth or extracted teeth, (43) and nally patients with history of systemic disease or craniofacial syndromes and presence of clefts. (43,44) Pre-intervention preparation First, a complete thorough explanation regarding the study procedures to both the participants and their parents in each group, and accordingly, an informed consent was obtained from each enrolled subject parents'.…”