Dentofacial effects of a modified tandem traction bow appliance.

The aim of this study was to evaluate the dentofacial effects of a modified tandem traction bow appliance (modified TTBA) in skeletal Class III subjects, and the effect of age on treatment response. The material consisted of the pre-treatment/pre-observation and post-treatment/post-observation lateral cephalograms and hand-wrist films of 45 children with skeletal and dental Class III malocclusions. Thirty patients were treated with a modified TTBA. Two treatment groups of 15 patients each were formed: an early (nine girls, six boys; mean skeletal age: 8.18 ± 0.50 years) and a late treatment (5 girls, 10 boys; mean skeletal age: 11.75 ± 1.00 years) group. The remaining 15 children (5 girls, 10 boys; mean skeletal age: 7.90 ± 0.62 years) were observed without treatment for 8 months and served as a control for the early treatment group. Wilcoxon and Mann-Whitney U-tests were used for statistical analysis. Significant forward maxillary movement was determined in both treatment groups (P < 0.01) while the decrease in SNB was significantly greater in the early treatment group compared with the control (P < 0.01). Upper molar tipping and sagittal displacement of point A (point A-T, N(⊥)FH-A) was found to be significantly greater in the late treatment group compared with the early treatment group (P < 0.05). In both treatment groups, dental and skeletal correction of the Class III malocclusion was achieved.

Modified tandem traction bow appliance compared with facemask therapy in treating Class III malocclusions.

OBJECTIVE: To compare the effects of the modified tandem traction bow appliance (MTTBA) and the facemask in treating patients with Class III malocclusion. MATERIALS AND METHODS: The material consisted of the pre-post treatment\pre-post observation lateral cephalograms of 65 subjects with skeletal and dental Class III malocclusion. In the first group 21 patients (mean age: 10 years, 6 months) were treated with a Delaire-type facemask (FM). In the second group 22 patients treated (mean age: 10 years) with MTTBA. The remaining 22 children (mean age: 9 years, 7 months) were observed without treatment for 11 months. RESULTS: Increase in SNA, N-FH ⊥ A, and ANB angles were significantly greater in the treatment groups compared to the control group. However, ANB angle showed a significantly greater increase in the FM group (2.8 ± 0.30°) than in the MTTBA group (2.0 ± 0.18°). The overjet and molar relation increased significantly in both treatment groups, but in the FM group (5.2 ± 0.40 mm) increase in overjet was significantly greater than in the MTTBA group (4.0 ± 0.27 mm). Mesial movement of upper molar and incisor were found to be greater in the FM group compared to the modified TTBA group. CONCLUSIONS: Both appliances were found to be effective in the treatment of Class III malocclusion. Their skeletal and dental effects showed differences due to their design.