Comparison of skeletal and dental changes with MSE (Maxillary Skeletal Expander) and Hyrax appliance using CBCT imaging

Author(s): Lin, Yiju | Advisor(s): Chiu, Robert; Moon, Won | Abstract: Introduction: The purpose of this study is to use Cone-Beam Computed Tomographic images to compare the skeletal and dental changes with MSE (Maxillary skeletal expander) and Hyrax appliance. Material and Method: 15 patients in MSE group and 8 patients in Hyrax group who met inclusion criteria were included. We used Independent-T test to compare the angulation of palatal sutures, bone bending and molar tipping between two groups. Result: In MSE group, the angulation of palatal sutures was 0.62 degree while it was 7.50 degree in the Hyrax group. (Pl 0.01) The bone bending was 1.39 degrees in MSE group and it was 3.77 degrees in Hyrax group. (Pl0.01) Molar angulation changes were 4.05 degrees in MSE group and 10.05 degrees in Hyrax group. (Pl0.01). Estimated molar tipping in MSE group was 2.66 degrees and 6.28 degrees in Hyrax group. Conclusion: This study showed that the MSE appliance was able to produce a more parallel palatal suture opening, less bone bending and less molar tipping than the Hyrax appliance. Cone-Beam Computed Tomography is a useful tool in quantifying the skeletal and dental changes after palatal expansion.