Miniscrew-Assisted Maxillary Expansion in Children with Compromised First Permanent Molars: A Systematic Review and Meta-Analysis

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 ([&ge;]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 28,879 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 ([&ge;]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.