Cephalometric Comparison of Treatment with Twin Block Appliance in Skeletal Class II Div 1 Patients with Normal and Vertical Growth Pattern
Author(s): Vahid Mollabashi, Maryam Behtari Nezhad, Maryam Shahdoost, Faezeh Yousefi, Kimia Saadat
Regarding the effects of increase in vertical dimension on the outcomes of treatment with functional appliances, this study was designed to evaluate the differences between the outcome of treatment with twin block appliance in patients with normal and vertical growth pattern. This prospective cohort study was done by counting all (census) method so any patient with class II malocclusion due to mandibular deficiency was entered to the study with an informed consent. Each subject had immediate pre-post treatment lateral cephalograms. There were 11 patients in normal (FMA≤28) & 16 patients in vertical (FMA>28) group. Pre-post treatment lateral cephalograms were digitized and analyzed by Dolphin Imaging software. The data were then subjected to Paired t test & ANKOVA analysis. There was a statistically significant (p<0.05) reduction in overjet, U1-NA, U1-SN, ANB in both groups. Patients with normal growth pattern show a statistically significant (p<0.05) increase in L1-NB, AFH & IMPA. In patients with vertical growth pattern a statistically significant (p<0.05) increase in SNB, L1-NB, Co-Go, Co-Gn, AFH, PFH, PFH/AFH, LAFH & ANS-PNS can be mentioned. In comparison between two groups, there was statistically no significant difference in any variable after treatment. Twin block appliance is effective in correcting skeletal class II malocclusion and there is statistically no significant difference in any variable after treatment between two groups.