Maxillary protraction effects of TTBA (Tandem Traction Bow Appliance) therapy in Korean Class III children

Kim, Hye Jin; Chun, Youn Sic; Lim, Won Hee

Abstract

OBJECTIVE
The purpose of this study was to investigate the maxillary protraction effects of the Tandem Traction Bow Appliance (TTBA), a new appliance devised several years ago for the treatment of growing skeletal Class III patients.
METHODS
Participants were 88 Korean children (42 boys, 46 girls) with skeletal Class III malocclusion treated with TTBA at the orthodontic clinic of Ewha Womans University Mokdong Hospital. Mean age at the start of treatment was 7.5 years +/- 1.5 years. Mean treatment periods were 13 +/- 3 months. Pretreatment and posttreatment lateral cephalograms were traced and superimposed by the same investigator and analyzed by modified McNamara analysis and pitchfork analysis. Changes were evaluated with paired t-tests at a significance level of p < 0.05.
RESULTS
The maxilla and maxillary dentition moved forward. The mandible moved backward, although not significantly; and the mandibular dentition moved forward. The net dental changes combined with the apical base change resulted in a favorable total molar relationship correction. Net dental movement was 26% and the apical base change 74% of the total molar relationship correction.
CONCLUSION
These results suggest that TTBA has a maxillary protraction effect that can be useful in the treatment of growing skeletal Class III malocclusion with maxillary deficiency.