Effectiveness of functional regulator II appliance in producing skeletal and dental changes and its permanence in class II patients compared to a control group: A retrospective cephalometric study

Aims: Class II skeletal and dental disparities due to mandibular retrusion have been termed as a major type of facial eccentricity. Functional appliance therapy is one of the treatment modalities aimed to correct the retrusive mandible during growth. We aimed at comparing the treatment changes between patients treated with functional regulator (FR) II appliance of Frankel and untreated class II control groups and to evaluate the permanence and long‑term stability of this treatment in Indian population. Materials and Methods: The treatment group (FR II/study group) comprised 10 patients who were evaluated at three stages: pretreatment (T₁), immediate postfunctional (T₂ at 18 months), and long‑term posttreatment (T₃ at 6 years). The control group comprised 10 untreated class II patients under observation for >4 years. Intergroup comparison was done using Student's t‑test, to test for statistical significance. Results: The FR II group also showed a significant decrease in ANB value, indicating a strong normalization of sagittal jaw discrepancy and increase in lower anterior facial height when compared with class II control group. Further, dentoalveolar changes had significant differences between the two groups. Conclusions: This retrospective cephalometric study indicates that FR II appliance therapy in skeletal class II malocclusion with retrognathic mandible during active growth phase brings about the correction of anteroposterior maxillo‑mandibular relationship that remains stable over long term.