Therapeutic Effect of Face Mask with Two Different Retention Plaques in Class III Children

Statement of Problem: The effects of simultaneous using of facemask with removable appliance and facemask with modified TPA Nance are not been compared till now. The aim of this study was to evaluate the therapeutic effect of facemask-modified TPA Nance and Facemask-Y- expander plate and comparison of these two appliances in 8-10 years old children with maxillary deficiency CLIII malocclusion by protraction the maxilla to forward. Purpose: This study performed to evaluate the therapeutic effect of facemask-modified TPA Nance and Facemask- Y-expander plate and comparison of those two appliances in 8-10 years old children with maxillary deficiency CLIII malocclusion. Materials and Methods: In this analytical retrospective study, 25 children who were referred to Dental Faculty and its clinics were selected by census sampling. All children had CLIII malocclusion and had been treated by two orthodontists. According to the treatment method the patients were divided into 2 groups: treated by facemaskmodified TPA Nance (group A) and Y-expander plate (group B). Lateral cephalometric radiography of the patients were hand-traced and before-after data were analyzed by SPSS22 Ver. Using Mann Whitney test for comparison of two methods and Wilcoxon to compare before-after effects (α=0.05). Results: SNA angel, ANB angel, Co-A distance, Witts angle, A-B Difference, Upper1-SN distance, Upper1-PP distance and Overjet in group A and SNA, ANB, Maxilla to cranium distance, witts angle, Anterior facial height Co-A distance A-B difference in group B were increased (P<0.05) and Insior Mandibular Plane Angle in both groups was decreased (P<0.05). In comparison of the two groups there is no difference in any of the parameters (P<0.05). Conclusion: Both treatment methods bring maxilla forward effectively therefore both methods are useful treatments. Skeletal vertical changes are low and acceptable in both groups. According to total superimpositions upper incisor and first molars in both groups have been extruded.