Quad Helix vs RME for Posterior Cross-bite in Egyptian Children

The study involves 20 orthodontic patients aged 9-12 years with posterior cross-bite. Group A will receive the Quad Helix appliance, while Group B will receive Rapid Maxillary Expanders. Evaluation will be based on orthodontic study models, clinical photographs, and various radiographs including CBCT. Treatment will continue until complete correction is achieved, followed by a 3-month passive retention period.