Is there any enhanced treatment effect on class II growing patients when Forsus Fatigue Resistant Device is reinforced by either miniplates or miniscrews? A systematic review and meta-analysis

Objective > To investigate the treatment effects, on skeletal class II growing patients, when mini plate-anchored Forsus Fatigue Resistant Device (MP-FFRD) and miniscrew-anchored Forsus Fatigue Resistant Device (MS-FFRD) were separately compared with conventional Forsus Fatigue Resistant Device (C-FFRD). Thus, distinguishing the differences between direct and indirect anchorages. Materials and methods > Comprehensive electronic and hand searching, without restrictions, were performed in CENTRAL, Scopus, Web of science, EMBASE via OVID, PubMed and ClinicalTrials.gov. Only randomized controlled trials (RCTs) and controlled clinical trials (CCTs) with patients receiving orthodontic functional treatment with MP-FFRD or MS-FFRD were included. Risk of bias was assessed using Cochrane's tools (RoB 2 and ROBINS-I). For quantitative synthesis, inverse variance method and standardized mean differences with 95% confidence intervals were chosen. Results > Four RCTs and three CCTs were included. All reviewed articles included 101 patients in the experimental group and 103 patients in the control group. Regarding MP-FFRD, the analysis included data from 78 subjects (39 MP-FFRD, 39 C-FFRD). The pooled estimates showed an increase in SNB (SMD = 0.7; 95% CI (0.21, 1.19); P = 0.005) and in mandibular length (Co-Gn) (SMD = 1.69; 95% CI (1.11, 2.27); P < 0.001) in MP-FFRD compared with C-FFRD. Additionally, a reduction in lower incisors' inclination was observed in MP-FFRD group (SMD =-3.13; 95%CI (-3.83,-2.43); P < 0.001). Concerning MS-FFRD, the analysis included data from 94 subjects (46 MS-FFRD, 48 CFFRD). No significant improvement was achieved in SNB (SMD = 0.19; 95% CI (-0.22, 0.60); P = 0.36), yet two studies out of three reported a better control in the lower incisors' inclination. Conclusions > According to the available evidence, the direct loading of FFRD on bilateral miniplates enhanced the skeletal and dental corrections in class II growing patients; however, the clinical significance of the statistical results is questionable. The treatment effects of the indirect loading of FFRD on miniscrews were mainly dentoalveolar, yet with better control of lower incisors' inclination.