Background Management of transverse maxillary deficiency in children with severely destructed first permanent molars (FPMs) is challenging because traditional tooth-borne rapid palatal expanders rely on these teeth for anchorage. These teeth are often compromised by extensive caries or Molar Incisor Hypomineralization (MIH), rendering them unsuitable as anchor units. Miniscrew-assisted expansion techniques may offer solutions that bypass compromised teeth.

Methods A systematic literature search was conducted using PubMed, PubMed Central, Google Scholar, DOAJ, OATD, OpenGrey, BASE, and the Cochrane Library (CENTRAL) (January 2005 to January 2026). Citation tracking and reference screening supplemented the search. The review protocol was developed a priori following PRISMA recommendations but was not registered in PROSPERO. Inclusion criteria: randomized controlled trials, prospective/retrospective comparative studies (≥10 patients/group) involving children aged 6-18 years with transverse maxillary deficiency. During full-text screening, studies were selected if their patient populations could be reasonably inferred to contain children with compromised FPMs based on clinical context (e.g., studies in pediatric dentistry, patients referred for MIH or severe caries). Risk of bias was assessed using the Cochrane RoB 2.0 tool for RCTs and ROBINS-I for non-randomized studies. Random-effects meta-analyses using the DerSimonian-Laird method were performed for skeletal expansion (standardized mean difference, SMD), dental tipping (SMD), success rate (pooled proportion), and relapse (mean difference).

Results From 28,592 initially retrieved records, 23 studies (1,847 patients; mean age 11.4 +/-2.3 years) were included after screening; 16 contributed to meta-analyses. Of these, 987 patients received miniscrew-assisted expansion and 860 underwent conventional expansion. Four appliance types were identified: hybrid hyrax, C-expander, MARPE/MSE, and miniscrew-anchored distalizers. Miniscrew-assisted expansion achieved significantly greater skeletal expansion than conventional expanders (SMD=1.24; 95% CI: 0.89 to 1.59; p<0.001; I2=58%). Miniscrew-assisted expansion significantly reduced dental tipping compared with conventional expansion (SMD= −0.98; 95% CI: −1.42 to −0.54; p<0.01; I2=51%). MARPE appliances demonstrated a pooled success rate of 93.9% (95% CI: 89.7% to 97.2%; I2=41%). Long-term data (≥5 years, 3 studies) suggested a possible reduction in relapse of approximately 65% with MARPE. Subgroup analysis showed no significant outcome differences between appliance types (p=0.24). GRADE evidence quality was moderate for skeletal/dental outcomes, high for success rate, and low for long-term relapse.

Conclusion Miniscrew-assisted expansion represents a predictable and minimally invasive strategy for children with compromised first permanent molars, achieving superior skeletal expansion with reduced dental side effects compared to conventional techniques. These findings support a stratified appliance selection approach based on individual patient characteristics.

The authors have declared no competing interest.

No funding was received for this study. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. The authors or their institutions at no time received payment or services from a third party for any aspect of the submitted work (including but not limited to grants, data monitoring board, study design, manuscript preparation, statistical analysis, etc.).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study used ONLY openly available human data from previously published studies. All data were obtained from peer-reviewed journal articles indexed in public databases (PubMed, PubMed Central, Cochrane Library, etc.) that were openly available before the initiation of the study. All included studies are cited in the reference list and can be accessed through their respective journals or through open-access repositories.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present study are available upon reasonable request to the authors. This includes: Extracted data from all 23 included studies Data extraction forms Meta-analysis outputs Statistical code used for analyses (RevMan 5.4 and Stata 17.0) Complete list of excluded studies (n=516) All included studies are published and cited in the reference list. Complete search strategies for all databases are provided in Supplementary File 1. Detailed funnel plot data and Egger's test results are provided in Supplementary File 3. Full risk of bias assessments are provided in Supplementary File 5.