Skeletal and Dental Effects of Forsus Fatigue Resistance Device Versus Twin Block Appliance for Class II Malocclusion Treatment in Growing Patients: A Systematic Review

Objective

This study systematically searched the literature and assessed the available evidence to compare the efficacy of Forsus Fatigue Resistance Device (FRD) versus Twin Block Appliance (TBA) in treating class II malocclusion.

Material and Methods

The search for published literature was published up to May 28, 2024. The databases were included in the search: MEDLINE, PubMed, EMBASE, Cochrane Oral Trials Register, Tripe, Web of Science, and Scopus. Additionally, unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and ProQuest Dissertations and Theses. All eligible studies were carefully reviewed and two reviewers independently extracted data. In cases of disagreement, an arbiter was consulted for resolution.

Results

Two randomized controlled trials (RCTs) and five non-RCTs were included in this review. The total number of patients included in the studies examining SNA, SNB, and ANB was 254. The studies also looked at the variables Go-Gn, L1-ML, and U1-SN, with 279, 205, and 277 patients included for each variable, respectively. According to the evidence reported, TBA showed greater skeletal effects in terms of mandibular length and advancement. The pooled estimate revealed a statistically significant 1.3° increase in the SNB, and a decrease of −1.34° in the ANB angles for patients treated with TBA compared with those treated with FRD, with no statistically significant differences in the SNA angle. Most studies had a moderate risk of bias, while only two studies had a high risk of bias.

Conclusion

FRD has been proven to be an effective treatment device for correcting ANB and restricting SNA angle, similar to TBA. However, TBA appears to offer better mandibular length and SNB outcomes.