The aim of this preliminary study was to compare the dentoalveolar and skeletal effects of two different Removable Functional Appliances (RFAs) in growing Class II, Division 1 subjects based on pre- and post-treatment cephalometric analyses. Forty subjects with Class II, Division 1 malocclusions were recruited from the undergraduate orthodontic clinic at the University of British Columbia for this clinical trial. All subjects were selected under the same inclusion and exclusion criteria and full orthodontic records were obtained for each subject. They were divided into two groups: 20 (12 males) in RFA-1 group and 20 (14 males) in RFA-2 group.
Results: There were no significant differences between the RFA-1 and RFA-2 groups in insertion age (10.4 ± 1.3 years and 10.7 ± 1.4 years, respectively) or treatment duration (163 ± 6.7 months and 16.1 ± 65 months, respectively). There was no significant difference in cephalometric variables between the two groups at baseline. After treatment, both groups demonstrated a statistically significant (P < 0.05) increased SNB and L1-Apo; decreasedANB, Wits, overjet and overbite.
Conclusions: The functional effects of RFA-1 and RFA-2 are comparable in Class II, Division 1 pre-adolescent patients in the same age group. The RFA-1 is effective in generating treatment changes as the suggested wear time was only during sleep.d.