THE EFFECTS OF FRANKELS FUNCTION REGULATOR (FR-4) THERAPY ON THE TREATMENT OF ANGLE CLASS-I SKELETAL ANTERIOR OPEN BITE MALOCCLUSION

The present study attempts to evaluate cephalometrically the effects o f Frankel's function regulator (FR-4) appliance on the treatment of An gle Class I skeletal anterior open bite malocclusion. Forty Turkish ch ildren (26 girls and 14 boys), with Angle Class I skeletal anterior op en bite, were randomly divided into two groups of 20 (13 girls and 7 b oys). Patients who had not undergone treatment served as the control g roup, whereas a second group was treated with lip-seal training and th e FR-4 appliance. Chronologic mean decimal age at initial period of th e investigation was 8.7 years in the treated group, and 8.9 years in t he control group. Treatment and observation periods were 2 years. Inve stigation was carried out on lateral cephalograms taken before and aft er the study period. The results indicate that a spontaneous downward and backward growth direction of the mandible observed in the control group could be changed to a upward and forward direction by FR-4 thera py. The skeletal anterior open bite was successfully corrected through upward and forward mandibular rotation.