The stability of Class II correction with functional appliance therapy and orthodontic camouflage: A retrospective cohort study.

OBJECTIVE: The aim of this study was to compare the stability of overjet reduction in adolescents treated with either orthodontic camouflage involving extraction of premolar units or functional appliance therapy. MATERIAL AND METHODS: A retrospective cohort study was undertaken with data collected at pre-treatment (T0), debond (T1) and 12 months post-treatment (T2). The primary outcome measure was stability of overjet reduction, and secondary outcome measures included Angle's molar relationship, and Little's Irregularity Index score. RESULTS: Forty-two Class II participants, 18 treated with a functional appliance and 24 with camouflage, were included with a mean pre-treatment age of 13.07 years (SD 1.72), with 23 (55%) being female. Mean overjet reduction during treatment in the functional appliance group was 6.99mm with relapse of just 0.62mm present at 12 months post-treatment. In the orthodontic camouflage group, there was a mean overjet reduction of 3.54mm with relapse of 0.27mm at 12 months post-treatment. Linear regression analysis confirmed no statistical difference (P=0.501) in overjet relapse between both treatment groups at 12 months post-treatment, adjusting for overjet at baseline. A further regression analysis revealed no significant association between overjet relapse and pre-treatment skeletal discrepancy, labial segment crowding, retention regime or compliance with the retention protocol. CONCLUSIONS: Both functional appliance and orthodontic camouflage therapies appear to have good antero-posterior occlusal stability, with minor degrees of overjet relapse occurring over a 12-month follow-up period. There was no significant difference between the treatments in relation to overjet relapse, buccal segment interdigitation or anterior irregularity.