Caries Experience in Children and Adolescents with Thalassemia: A Systematic Review and Meta-analysis

Introduction Thalassemia creates a distinct and compounding oral risk environment, characterized by transfusion-related salivary gland dysfunction, thalassemia-driven craniofacial remodeling, polypharmacy, and constrained access to preventive dental care, that may substantially elevate dental caries susceptibility. Yet the true magnitude of this burden across global populations has remained unquantified. This review aimed to synthesize evidence on caries experience, assessed using the Decayed, Missing, and Filled Teeth indices for permanent (DMFT) and primary dentition (dmft), in children and adolescents with thalassemia compared with healthy controls. Methods This PRISMA 2020 compliant systematic review and meta-analysis was prospectively registered with PROSPERO (CRD42024603110). Five databases were searched from January 2000 to January 2026 for cross-sectional and case-control studies in individuals aged ≤18 years with any thalassemia type. Risk of bias was appraised using the Newcastle-Ottawa Scale and JBI Checklist. Pooled mean differences (MD) with 95% confidence intervals (CIs) were derived using random-effects models, and certainty of evidence was graded using GRADE. Results 22 studies from 12 countries were included; most involved transfusion-dependent children and adolescents with β-thalassemia major and 13 contributed quantitative data. Children with thalassemia had significantly higher caries experience in both permanent dentition (10 studies; n = 1,646; MD = 1.41, 95% CI: 0.36 - 2.45) and primary dentition (6 studies; n = 1,256; MD = 1.59, 95% CI: 0.39 - 2.79). However, heterogeneity was very high across both outcomes, publication bias was substantial, with trim-and-fill adjustment rendering the permanent dentition estimate non-significant and GRADE certainty was rated very low. Conclusion Unadjusted analyses indicated higher mean DMFT and dmft among children and adolescents with thalassemia; however, prediction intervals crossed zero, and substantial heterogeneity and possible reporting bias, including small-study effects, limit confidence in the stability of the observed effect. The certainty of evidence was very low, precluding a stable estimate of the magnitude of the association. Most evidence concerned transfusion-dependent children and adolescents with β-thalassemia major, limiting the generalizability of findings to other forms of thalassemia. Preventive dental care remains justified on clinical and mechanistic grounds, despite the uncertainty in the quantitative evidence.