The persent paper describes 4 slinical cases of Hellman dental age III A group of functional Class III malocclusion in which the horsehoe appliance was applied to obtain normal anteroposterior relationship between jaws. What is the most noteworthy in the result from the use of this appliance is thet minimum down and backward rotation during backward repositioning of the mandible is noticed and the excellent retentive property in itself makers allowance for effective orthopedic correction in mixed dentition with anterior crossbite.