Limitations of the study
Due to ethical concerns, this research did not include a control group that was not given any therapy in order to determine the skeletal treatment effects and airway modifications of both appliances compared to natural development. In addition, two-dimensional measurements on the lateral cephalometric radiographs cannot reveal the changes in the third dimension (transverse dimension of the airway). Finally, it is important to highlight that the short follow-up period of six months may be insufficient for evaluation, which also might have impacted the MB results, since it took most of the children two months to adapt to the appliance, achieving the required wear-time per day. To overcome this, Patients were observed for an additional six months after the trial period ended to assure the retentive period and prevent any relapses that could have occurred during the study period. At that stage, patients who needed further treatment were referred to the Orthodontic Department for fixed appliance therapy.