Changes of hard tissues in patients with functional and skeletal Angel Class III malocclusion after FRIII appliance treatment

To compare changes of hard tissues before and after treatment of functional and skeletal Angle Class Ⅲ malocclusion with FRⅢ appliance.Thirty patients with functional and skeletal Angel Class Ⅲ malocclusion were selected and treated with FRⅢ appliance. SPSS 22.0 software package was performed for statistical analysis.After treatment, there was no significant difference in SNA, S-Ptm, ANS-Ptm and Go-Po (P>0.05). ANB, ANS-Me, ANS-Me /N-Me were increased significantly (P<0.01). SNB, L1-NB, L1-MP were decreased significantly (P<0.05). MP-FH, Y axis, U1-NA, U1-NA (mm), U1-SN were increased significantly (P<0.05).After FRⅢ appliance treatment of Angel Class Ⅲ malocclusion, the position of mandible may rotate clockwise downward and backward， with retrusion of the lower incisors and protrusion of the upper incisors.