Association of low birth weight with development defects of enamel: Systematic review with meta-analysis.

OBJECTIVE: Low birth weight (LBW) has been associated with developmental defects of enamel (DDE), but this has not been tested against an etiological physiological model of DDE (Eti-Phys model). This study aimed to investigate the associations: (i) between LBW and DDE as well as molar-incisor hypomineralization (MIH) in deciduous (DEC) and permanent teeth (PERM), and (ii) between observed and Eti-Phys-model-based predicted (model-based) risk of DDE. DESIGN: Cross-sectional, cohort, and case-control studies were identified in PubMed, ISI Web of Science, LILACS, SCOPUS, and Embase until April 2024, supplemented by grey literature searches. Random-effects model meta-analyses were performed for LBW in DDE/MIH. Subgroup analyses examined the PRE risk of DDE. RESULTS: 60 articles were included in meta-analyses. Observed and model-based risks of DDE were correlated (p < 0.001, r = 0.64) [DDE in permanent (relative risk =1.30; 1.02-1.64) < DDE in DEC (RR= 1.76; 1.52-2.04) < DDE in DEC+veryLBW (RR = 2.55; 2.09-3.10) < hypoplasia in DEC (RR= 3.30; 2.35-4.62) < hypoplasia in DEC+veryLBW (RR = 4.62; 3.26-6.56)] in DEC, but not in PERM (p = 0.49). Limited data on LBW versus MIH hindered the calculation of an association between observed and model-based risks of DDE. CONCLUSION: Combined with the Eti-Phys model of DDE, the evidence suggests a causal association between LBW and DDE in the deciduous, but not in the permanent dentition. Evidence on LBW and MIH remains limited.