Aim: The purpose of this clinical prospective study was to compare between class II elastics and a “no compliance" fixed functional appliance therapy SUS² (Sabbagh Universal Spring 2, Dentaurum, Ispringen, Germany) with respect to the skeletal and dental changes following correction of Class II division 1 malocclusion in adolescent subjects compared to a matched untreated Class II control group.
Materials and Methods: The study was carried out on 30 female patients with Class II, division 1 malocclusion with a mean age of 14.5 years old. All patients were matched regarding cause of malocclusion with mandibular retrognathia being the main source. The growth pattern was normal or low-angle. The subjects were randomly allocated into 3 groups, each group comprising 10 patients: Group 1 (SUS²), Group 2 (Class II elastics) and Group C (Control group). Treatment/observation were carried out for an average period of 8 months. The appliances were removed when a Class I dental relationship was achieved. Pre- and post-treatment/observation lateral cephalograms were analyzed to determine the treatment effects. Student's paired t-test and Chi-squared test were used for intragroup and intergroup comparisons.
Results: There was an overjet reduction in both groups with a marked improvement towards normal Class I occlusion. Skeletal effects were more marked in SUS² group compared to Class II elastics group with a mean decrease in angles SNA , ANB and MP/SN (-0.89±0.9°, -1.97±1.2°,and -0.8±1.3° respectively) while an increase was evident for angle SNB and Co-Gn (1.08±0.5°and 2.1±0.9mm) respectively. All linear skeletal parameters showed statistically significant changes in the SUS2 group except MP/SN while in the Class II elastics no statistically significant changes were observed except for angle MP/SN that showed statistically significant increase (1.5±1.2°). U1/SN angle showed statistically significant decrease in both treatment groups (P<0.01) while L1/MP showed statistically significant increases but were more pronounced in Class II elastics group (P<0.01).
Conclusions: SUS² is more effective than Class II elastics in the treatment of skeletal Class II maloccluion as it yields mild but more favorable skeletal results and less dentoalveolar side effects.