High prevalence of molar-incisor hypomineralisation in sickle cell disease children and the association with haematologic profile: a retrospective cohort study

PURPOSE: This study aimed to compare molar incisor hypomineralisation (MIH) prevalence and severity in children with sickle cell disease (SCD) versus healthy controls, whilst investigating associations with haematologic parameters and phenotypic disease expression. METHODS: A retrospective cohort study included 60 SCD children (6-14 years) from a Brazilian haematology centre and 605 age-matched healthy controls, assessed between August 2022 and June 2023. Comprehensive dental examinations assessed MIH presence and severity. Laboratory investigations included complete blood count analysis (with erythroblast quantification) and phenotypic characterisation of SCD. Additional data collection encompassed dental anxiety, hypersensitivity, and aesthetic questionnaires for SCD participants. Statistical analysis employed chi-square, Mann-Whitney U, and Fisher's exact tests (α = 0.05). RESULTS: The SCD group demonstrated significantly higher MIH prevalence compared to control (63.3% vs. 18.2%; p < 0.001) with a prevalence ratio of 3.48 (95% CI 2.66, 4.54). While severity distribution differed between groups (p < 0.001), severe MIH was less frequent in SCD (6/60 vs 32/605 controls; prevalence ratio = 1.72, 95% CI 1.05, 2.81; p = 0.03). MIH in SCD showed strong associations with the vaso-occlusive phenotype (86.8% of cases, p < 0.001) and reduced erythroblast counts (p = 0.014), but no significant correlations with demographic factors or reported dental symptoms. CONCLUSION: Children with SCD showed a significantly higher prevalence of MIH compared with healthy controls. In the SCD group, MIH was associated with the vaso-occlusive phenotype and lower erythroblast counts.