Background factors of molar-incisor hypomineralization in a group of Finnish children

Acta Odontol Scand. 2014 Nov;72(8):963-9. doi: 10.3109/00016357.2014.931459. Epub 2014 Jul 9.


Objective: Molar-Incisor Hypomineralization (MIH) is a common developmental enamel defect characterized by demarcated opacities in permanent molars and incisors. Its etiology still remains unclear. The aim of this retrospective cohort study was to assess if the socioeconomic environment of the child is associated with MIH.

Materials and methods: The study was located in two rural towns and three urban cities in Finland. A total of 818 children, between 7-13 years old, were examined for MIH using the evaluation criteria in line with those of the European Academy of Paediatric Dentistry, but excluding opacities smaller than 2 mm in diameter. The mothers filled in a questionnaire which included questions related to the family's way of living (e.g. area of residency, farming, day care attendance) and socioeconomic status (family income, number of mother's school years, level of maternal education).

Results: The prevalence of MIH in the study population was 17.1%. Family income, urban residency and day care attendance were associated with MIH in the univariate analysis. In the multivariate analysis using binary logistic regression, only urban residency during a child's first 2 years of life remained associated with MIH. The prevalence of MIH in urban areas was 21.3% and in rural areas 11.5% (OR = 2.18, CI = 1.35-3.53, p = 0.001).

Conclusions: The prevalence of MIH was related to urban residency and could not be explained by any other factor included in the study.

Keywords: aetiology; developmental enamel defects; hypomineralization; socioeconomic status; urban living.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Agriculture / statistics & numerical data
  • Breast Feeding / statistics & numerical data
  • Child
  • Child Care / statistics & numerical data
  • Cohort Studies
  • Dental Enamel Hypoplasia / epidemiology*
  • Educational Status
  • Female
  • Finland / epidemiology
  • Humans
  • Income
  • Male
  • Mothers / education
  • Prevalence
  • Residence Characteristics
  • Retrospective Studies
  • Rural Health / statistics & numerical data
  • Smoking / epidemiology
  • Social Class
  • Socioeconomic Factors
  • Urban Health / statistics & numerical data