Non-Cochrane · intervention · PM42211288
Skeletal and Dentoalveolar Changes Following the Functional Treatment of Skeletal Class II Growing Patients: A Systematic Review and Meta-Analysis.
Almrayati Dima M, Hajeer Mohammad Y, Alam Mohammad Khursheed, et al. · Cureus · 2026 · PubMed · doi:10.7759/cureus.109730
Findings
Population Growing patients with skeletal Class II malocclusion (ANB > 4 degrees, mandibular retrognathia)
8 findings
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | Bjork's sum (NSAr + SArGo + ArGoMe) End of active treatment | MD -0.48 [-2.89, 1.92] Moderate Downgraded: risk of bias 2 studies · 92 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | Upper incisor inclination (UI-SN angle) End of active treatment | MD -3.55 [-5.11, -2.00] Moderate Downgraded: risk of bias 3 studies · 142 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | Lower incisor inclination (LI-MP angle) End of active treatment | MD 3.08 [1.66, 4.50] Low Downgraded: risk of bias, inconsistency 3 studies · 142 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | Jarabak's ratio (posterior/anterior facial height) End of active treatment | MD -0.02 [-1.78, 1.73] Low Downgraded: risk of bias, inconsistency 2 studies · 92 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | ANB angle End of active treatment | MD -2.43 [-3.99, -0.87] Low Downgraded: risk of bias, inconsistency 3 studies · 130 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | SNB angle End of active treatment | MD 2.42 [1.23, 3.61] Low Downgraded: risk of bias, inconsistency 3 studies · 130 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | SNA angle End of active treatment | MD -0.53 [-1.50, 0.44] Moderate Downgraded: risk of bias 3 studies · 130 participants |
| Twin-block removable functional appliance | Pre-treatment baseline (change from baseline to end of active treatment) | MM angle (maxillary-mandibular planes) End of active treatment | MD -0.41 [-2.23, 1.40] Moderate Downgraded: risk of bias 2 studies · 92 participants |
Included primary studies 6
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Alali 2014 A prospective controlled evaluation of Class II division 1 malocclusions treated with fixed lingual mandibular growth modificator. PMID:23987240 | 2014 | this review only | not stated | not extracted yet |
| Alsilq 2025 Dentoskeletal effects of aesthetic and conventional twin block appliances in the treatment of skeletal class II malocclusion: a randomized… PMID:39805909 | 2025 | this review only | not stated | not extracted yet |
| Burhan 2015 Dentoskeletal effects of the Bite-Jumping Appliance and the Twin-Block Appliance in the treatment of skeletal Class II malocclusion: a… PMID:25296729 | 2015 | this review only | not stated | not extracted yet |
| Idris 2019 Soft- and hard-tissue changes following treatment of Class II division 1 malocclusion with Activator versus Trainer: a randomized… PMID:29617755 | 2019 | this review only | not stated | not extracted yet |
| Quintao 2006 Soft tissue facial profile changes following functional appliance therapy. PMID:16113035 | 2006 | this review only | not stated | not extracted yet |
| Varlik 2008 Comparison of the effects of Twin Block and activator treatment on the soft tissue profile. PMID:18281262 | 2008 | this review only | not stated | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Healthy growing individuals with skeletal Class II malocclusion; removable appliances 9 to 13.5 years, fixed appliances 11 to 14 years | 276 growing patients with skeletal Class II (ANB > 4 degrees) and mandibular retrognathia; ages 8 to 13.5 years (n=6 studies) |
| Intervention | Removable functional appliances (RFAs) or fixed functional appliances (FFAs) | Twin-block (n=4), Activator (n=2), Bite-Jumping Appliance (n=1), Trainer (n=1), Aesthetic Twin-block (n=1), FLMGM fixed appliance (n=1) |
| Comparison | Untreated subjects or patients treated with a different functional appliance | Untreated controls (n=3 studies) or another functional appliance (n=3 studies) |
| Outcomes | Skeletal and dentoalveolar changes on lateral cephalometric radiographs | SNA, SNB, ANB, Bjork's sum, Y-axis, Jarabak's ratio, MM angle, upper and lower incisor inclination |
| Study designs | RCTs and controlled clinical trials | 4 RCTs and 2 CCTs |
| Timing | Active treatment period | 8 to 12 months of active treatment; no follow-up beyond active treatment |
AMSTAR 2 items
Two independent extractors rated each item. Their ratings are shown side by side because they have not been reconciled yet. The overall rating follows Shea et al. 2017: one critical flaw gives Low, more than one gives Critically Low.
| Item | Extractor A | Extractor B | Agree |
|---|---|---|---|
| 1Research question includes PICO components | Yes | Yes | yes |
| 2Protocol established before the reviewcritical | Partial Yes | Partial Yes | yes |
| 3Choice of study designs explained | No | No | yes |
| 4Comprehensive literature searchcritical | Partial Yes | Partial Yes | yes |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | Yes | Yes | yes |
| 7List of excluded studies with reasonscritical | Yes | Yes | yes |
| 8Included studies described in detail | Yes | Yes | yes |
| 9Risk of bias assessed satisfactorilycritical | NRSI: Yes · RCT: Yes | NRSI: Yes · RCT: Yes | yes |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | NRSI: No · RCT: No | NRSI: No · RCT: No | yes |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | No | No | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Critically Low | Critically Low | yes |