Dento-Skeletal Effects of the Myofunctional 8-Appliance in Growing Patients

This study aimed to evaluate the dento-skeletal effects of the Myofunctional 8-Appliance (MF8A) in growing patients with transverse dentoalveolar deficits. The primary research question was whether MF8A could guide dental arch growth by supporting tongue function in patients showing transverse deficiencies.

The study was conducted on 18 patients (aged 6-10 years) with mixed dentition. Patients were treated with the MF8A for at least 16 h daily and monitored monthly. Cephalometric radiographs and dental casts were obtained before treatment (T0) and after therapy (T1). Cephalometric analysis assessed skeletal and dental angular/linear changes, while 3D dental cast analysis measured arch dimensions. Statistical significance was set at p < 0.05.

Cephalometric analysis revealed no significant skeletal changes, except for an increase in the I+/ANS-PNS angle (p = 0.049), suggesting improved upper incisor inclination. Dental cast analysis showed significant transverse expansion in both arches, including increased intercanine, interpremolar, and intermolar widths (p < 0.001). Upper and lower arch depths also increased significantly, whereas lower arch perimeter changes were not statistically significant.

The MF8A demonstrated effectiveness in producing dentoalveolar expansion, primarily through functional re-education of tongue posture, while exerting minimal skeletal changes.