Background: The present study analyzed the changes obtained on the upper airway and hyoid bone dimensions in a group of patients with skeletal Class II malocclusion treated with functional elastodontic devices compared to an untreated control group. Methods: A group of 33 patients (19 females and 14 males) with Class II malocclusion treated with AMCOP®SC elastodontic device was compared with a control group of 35 subjects (17 females and 18 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start (T0) and end of treatment/period of observation (T1). Cephalometric analysis was performed and linear measurements to evaluate airway space and hyoid bone position were also obtained. A multivariate analysis of variance for repeated measures (MANOVA) was performed to determine the effects of interactions for the groups for time. Results: Statistically significant differences were found in the study group from T0 and T1 with an improvement of superior upper airway (SPASp< 0.0001), while in the control group it did not change in a statistically significant way from T0 to T1. The MANOVA test showed statistically significant differences between the two groups for the changes of SPAS (p= 0.003), IAS (p= 0.049), and H-C3 vertical (p= 0.038) values. Conclusions: Functional elastodontic therapy produced significant favorable airway changes in skeletal class II subjects.