Enamel Defects Among Orphanage Children: A Multi-Country Case–Control Study

Introduction and Aims Enamel defect, molar incisor hypomineralisation (MIH) and hypominiralised second primary molars (HSPM) are linked to increased treatment complexity. Early-life stress is a risk factor, though difficult to measure because of reliance on subjective recall. Orphaned children, often exposed to chronic stress and deprived of parental care, represent a vulnerable population. Accordingly, this case–control study aims to compare the prevalence of enamel defects and MIH/HSPM among children living in orphanages with the same in children living with both parents across 6 countries. Methods A matched case–control study was conducted across 6 countries (Saudi Arabia, Egypt, Yemen, Syria, Jordan and Pakistan) from December 2023 to December 2024. Dental examinations for children living in orphanages and living with both parents were performed using WHO and EAPD diagnostic criteria. Caregivers were interviewed using a questionnaire on child’s demographic data and medical history. Results A total of 1,838 children aged 7-10 years were included: 539 orphans and 1,299 controls living with both parents. Orphaned children had a significantly higher prevalence of enamel defects and MIH in first permanent molars (39.9% and 29.1%) compared to controls (29.8% and 22.3%) ( P < .001). HSPM prevalence was also higher among orphans (15.4% versus 7.9%). However, no significant difference was found in MIH affecting incisors. The results showed a chronological pattern: earlier-developing teeth were more affected. Conclusion Living in an orphanage is associated with a higher risk of MIH and enamel defects, particularly in early-forming teeth. These findings support a possible role for early-life stress in enamel development. Preventive programs and early screening are recommended for at-risk populations.