Cross-sectional and retrospective study regarding the changes in the spatial position of the hyoid bone and upper airways before and after orthodontic therapy in developing patients with normocclusion

ObjectiveThe objective was to study the effect of orthodontic therapy regarding the position of the hyoid bone and upper airways in nighty-one 6-21 year-old Caucasian patients with normoclussion.MethodsNineteen variables were analyzed by teleradiography. The differences were analyzed with the ANOVA test of repeated measures with an intra-group factor for two occasions.ResultsThe statistical analysis revealed a greater influence on the variables Hy-MP (12.3 vs 14.2), Hps-C3 (25.2 vs 28.1), Hpi-C3 (28.8 vs 35.5), H degrees-C3 (14.4 vs 12.7), Hps-Rg (36.0 vs 42.7), Hpi-Rg (34.1 vs 39.7), USP (16.2 vs 20.2), MPP (12.9 vs 14.8), C3P (10.6 vs 12.8), PNS-Ba (43.5 vs 66.5), PtV-Ad (12.0 vs 17.1) and PtM-Ba (33.9 vs 35.9), and Ad2-SO (24.16 vs 20.87).DiscussionSignificant differences were observed between most of the airway and hyoid bone variables before and after orthodontic treatment in our Spanish pediatric population, especially in the nasopharynx.