Skeletal, Dental And Soft Tissue Changes And The Ratio Of Soft Tissue To Hard Tissue Movements During Twelve Months Of Function Regulator Type 3 (FRâ…¢) Treatment.

The aims of this study were to evaluate the dental, skeletal and soft tissue effects of the FRⅢappliance, and the ratio of soft tissue to hard tissue movements during twelve months of function regulator type 3 (FRⅢ) treatment.The material of this study consisted of 25 patients with functional ClassⅢmalocclusions who referred to the Department of Orthodontics, Huaxi Stomatology Hospital , University of Sichuan. 11 boys and 14 girls. They were selected to treated exclusively with the FRⅢappliance for this study. The mean ages of the subjects in the beginning (T0) and after the appliance has been taken for about 12 months (T12) was 9.9±1.4 years and 10.7±1.1 years. Cephalograms was taken individually at T0 and T12. Control groups: (1) Group one: Sixty-four cephalograms of the patients (31 boys and 33 girls) before their treatment started, which have the similar occlusal and skeletal characters with the treatment group. The mean ages of the subjects was 9.8±0.3 years. (2) Group two: Sixty-four cephalograms of the patients (32 boys and 32 girls) before their treatment started, which have the similar occlusal and skeletal characters with the treatment group. The mean ages of the subjects was 10.9±0.3 years.After 12 months'treatment of FRⅢ: (1) The increase of the Go-Pog and Co-Go length were restrained. The ANB angle increased, the SNB angle decreased. The mandibular bone moved backward. The MP-FH angle and the OP-FH angle rotated clockwisely. The effects of FRⅢtreatment on the S-Ptm, ANS-Me,N-Me, ANS-Me/ N-Me, Co-Go/N-Me, SNA angle, PP-FH angle,PP-MP angle was less marked. (2) The nasal labium angle and the Pog labium angle increased. The retrusion of lower incesors was found in this study. Whereas the protrusion of the Sn position was also present.The tissue profile of the patient become more attractive. The ratio of A-OLP to LL-OLP was0.8/1,and the ratio of L1-OLP to Pm'-OLP was 0.6:1.FRⅢcan block the growth of the mandibular bone. After the treatment of FRⅢ, the mandibular has a downward and backward rotation. The tissue prlfile of the patient become more attractive. The ratio of A-OLP to LL-OLP was 0.8:1,and the ratio of L1-OLP to Pm'-OLP was 0.6:1.