Ming Y, et al. - The authors performed this meta-analysis, in growing class III patients with maxillary retrognathism, to evaluate the efficacy of maxillary protraction appliances (MPAs) on improving pharyngeal airway dimensions. Among growing skeletal class III subjects with maxillary retrusion, MPAs could increase post-palatal and nasopharyngeal airway dimensions. It could be suggested that in children with maxillary retrusion by enlarging airway space, MPAs have the potential to reduce the risk of obstructive sleep apnea syndrome.