The following cases describe three sisters with anterior open bite (overbite between 0 and –4.5 mm) coinciding with vertical growth pattern. All patients showed tongue thrusting and tongue-tip protrusion. They underwent functional appliance and fixed straight-wire appliance therapy primarily. Bite closure was effected by premolar extraction. Orthodontic treatment was supported by speech therapy. All cases resulted in a stable Class I molar relationship with an overbite of 2 mm. The results remained stable 6–8 years after the end of treatment. Speech and tongue function were physiological.