Proteomic profiling of human dental enamel affected by molar incisor hypomineralisation of different clinical severity grades: an in vitro study

Purpose: The aim of this study was to explore the potential to profile and distinguish varying clinical severity grades of MIH, compared to normal enamel, using proteomics.

Methods: Liquid chromatography-mass spectrometry analyses were conducted on enamel samples of extracted teeth, from 11 children and adolescents, spanning an age range of 6-18 years. Enamel powder samples were collected from extracted, third molars (n = 3) and first permanent molars diagnosed with MIH (n = 8). The MIH tooth samples were categorized into subgroups based on clinical severity grade. The data were statistically analyzed using ANOVA and Welch's t test.

Results: Teeth affected by MIH exhibited a diverse array of proteins, each with different functions related to dental enamel, distinguishing them from their normal enamel counterparts. The application of microdissection combined with LC-MS techniques has revealed the potential to discern unique proteomic profiles among MIH-affected teeth, characterized by varying clinical severity grades. Both analyzed MIH groups displayed consistent trends in the presentation of biological processes, including underabundance of proteins primarily associated with cell organization and biogenesis. Furthermore, proteins linked to cell death were overabundant in both MIH groups.

Conclusion: Proteomics enabled the detection and differentiation of various proteins across different clinical severity grades of MIH.