Aim: The aim of this study was to determine the prevalence and severity of molar incisor hypomineralisation in 6-12-year-old children living in Northern Poland.
Materials and methods: The study involved 1437 children aged 6 to 12 years. The dental examinations took place at the school and were performed in daytime classroom lighting conditions by a single paediatric dentist. The students were examined with headlamp, oral mirror and dental probe. Teeth were not cleaned or dried before examination. All surfaces of the index teeth were examined and diagnosed MIH according to Weerheijm et al. criteria. The severity was recorded as mild or severe according to EAPD criteria.
Results: Of all children, 6.43% exhibited signs of MIH on first permanent molars (FPMs) and in 50% of them permanent incisors (PIs) were also affected. There were differences in the MIH prevalence between genders (5.79% female vs. 6.47% male) and place of living (6.4% rural vs. 5.96% urban), without statistical significance. Girls were more likely to have severe lesions, which was statistically significant. The highest incidence of MIH was found in the group of six-year-olds (11.5%), and the lowest in the group of ten- (2.7%) and twelve-year-old (2,65%). Also MIH occurred statistically more often in children up to 8 years of age, compared with children over 8 years of age (8.24% and 4.24%, respectively).
Conclusion: In North Poland the prevalence of MIH is 6.43%.