Early and late treatment effects of modified tandem traction bow appliance

The study material consisted of 30 patients having skeletal ages 6 to 9 years and 15 patients having skeletal ages 10 to 14 years with dental and skeletal Class III malocclusion with maxillary deficiency or combined maxillary deficiency and mandibular overgrowth and anterior crossbite. An early treatment and a control group constructed with 15 patients in each group randomly chosen from 30 patients (skeletal age 6-9 years). A late treatment group constructed with 15 patients (skeletal age 10- 14 years). The average skeletal ages were as 8 years 2 months for the early treatment group, 11 years 9 months for the late treatment group and 7 years 11 months for thecontrol group. Lateral cephalometric, panaromic and hand-wrist radiographs were taken before and after treatment/observation. In both groups all patients were treated with Modified Tandem Traction Bow Appliance. The patients were instructed to wear the appliance 14-16 hours per day until approximately 2 mm overjet was achieved. The treatment period was found 9,36 months for early treatment group and 11,28 months for late treatment group. The observation period was found 8,64 months 62 parameters obtained from the lateral cephalometric radiographs that was taken before and after treatment were measured. Statistical analysis were made with `Repeated measurement factorial designed ANOVA teqnique? to evaluate the changes and the differences between the groups and to determine the skeletal and dental effects occurred during treatment. After the treatment of `Modified Tandem Traction Bow Appliance; in both early and late growth periods maxillary forward displacement were observed. The maxillary-mandibular relationship was corrected especially because of the forward movement of the maxilla and no significant anterior rotation of maxilla was found in both treatment groups. In both treatment groups, labial tipping of upper insicors, lingual tipping and retrusion of lower insicors and distalization of lower molars were observed and no significant difference was found between the groups. Overjet and molar relationship, were increased due to both skeletal and dental correction in early treatment group but were increased mostly due to skeletal correction in late treatment group.