L'Orthodontie Française


What do we currently need to know about molar incisor hypomineralisation (MIH) and hypomineralized second primary molars (HSPM)? Volume 94, issue 3-4, Septembre-Décembre 2023


  • Figure 1

  • Figure 2

  • Figure 3

  • Figure 4

  • Figure 5

  • Figure 6
1 UFR Sciences odontologiques, 146 rue Léo Saignat, 33000 Bordeaux, France
2 PACEA UMR 5199, B8, allée Geoffroy-Saint-Hilaire, 33600 Pessac, France
Correspondance : julia.estivals@u-bordeaux.fr


Molar incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPM) are qualitative and asymmetric enamel defects. MIH affect at least one permanent first molar and can also be associated with permanent incisors. HSPM affect at least one primary second molar and possibly primary canines. Hypomineralized enamel is characteristic: the enamel prisms are disorganized, less distinct, the interprismatic space is more marked, the mineral density is decreased and the protein content is increased. Currently, etiologies remain unknown but the various studies tend towards a multifactorial model with several systemic, genetic and/or epigenetic factors, acting in a synergistic or additive way.

Material and Method

The authors highlight the various factors involved in diagnosing MIH and HSPM. A review of the prevalence (French and worldwide) and etiologies of these pathologies is also provided, to enable practitioners to answer any questions parents may have.


The knowledge of these different elements on diagnosis, structure, prevalence and etiologies will allow the orthodontist to better collaborate with the dentist but also with the parents in order to ensure an adequate dental and orthodontic management.