ABSTRACT
Objective:To assess the effect and mechanism of ClassⅢ malocclusions treatment with Frankel-Ⅲ appliance and reverse Twin-block appliance. Methods:Twenty subjects of ClassⅢ malocclusion were included in this study(9 males,11 females). Among them, 10 subjects were randomly selected for treatment with reverse Twin-block appliance (T group) and 10 subjects for Frankel-Ⅲ appliance (F group). All patients were treated all the day for total of 4-11 months. The cephalometric records of these subjects were examined before and after treatment. The acquired data were processed with SPSS 10.0. Results: The results showed a mandible receded backward in both groups. Both group could accelerate the development of the maxillary bone. But the Frankel-Ⅲ was more effective. F group had significant effects of uprighting upper frontal teeth and flaring lower teeth. the average treatment time was 6.5 months in reverse twin-block appliance therapy group and 9 months in Frankel-Ⅲ appliance group. Conclusion: Both reverse Twin-block appliance and Frankel-Ⅲ appliance can treat angle classⅢ malocclusions effectively. The effects of maxillary changes of Frankel-Ⅲ appliance is better than reverse Twin-Block. Treatment period is shorter in T group than in F group.
ABSTRACT
Objective: To evaluate the effects of the modified fixed r everse Twin-block appliance(TBA) combined with maxillary protraction appliance( MPA) in the treatment of early Angle Ⅲ skeletal anterior crossbite. Met hods:TBA combined with MPA was used in 15 growing subjects with early An gle Ⅲskeletal malocclusion (group TBA-MPA). Another 15 subjects with the same type of malocclusion were treated by MPA(group MPA). The effects of treatment we re studied by cephalometric measurments.Results:3-5 months afte r treatment SNB, B-Vert T, Po-Vert T,NPo-FH,Co-Po and 1-NB in group 1 were decreased more than those in group 2 (P0.05).Conclusion:Angle Ⅲ skeletal ante rior crossbite can be corrected successfully with reverse TBA combined with maxi llary protraction appliance by mandible retrusion and maxilla forward growth.