# Hypersensitivity associated with molar-incisor hypomineralisation (MIH) among elementary schoolchildren in Bavaria, Germany: results from a cross-sectional study

## TL;DR

This study found that hypersensitivity in children with molar-incisor hypomineralisation is relatively low, with demarcated opacities being less likely to cause sensitivity.

## Contribution

The study provides new population-based data on hypersensitivity in children with MIH in Bavaria, Germany.

## Key findings

- MIH prevalence was 17.5% among 8- to 10-year-olds in Bavaria.
- Demarcated opacities were significantly less likely to be associated with hypersensitivity.
- Enamel breakdown did not show a significant association with hypersensitivity.

## Abstract

This cross-sectional epidemiological study aimed to provide population-based data on hypersensitivity associated with molar–incisor hypomineralisation (MIH) in 8- to 10-year-olds from Bavaria, Germany. It was hypothesized that hypersensitivity would be equally distributed among MIH teeth.

A total of 5418 schoolchildren (8–10 years) were examined using the MIH criteria of the European Academy of Paediatric Dentistry (EAPD) and the MIH Treatment Need Index (MIH-TNI). MIH-TNI 1 was linked with mild MIH; MIH-TNI 2–4 corresponded to severe MIH. Hypersensitivity was recorded dichotomously (yes/no) after a two-second, 2.8-bar air blast (Schiff test). Descriptive statistics and a mixed-effects logistic regression model—adjusted for age, sex, region, tooth type, and caries status—explored hypersensitivity in MIH-affected teeth.

The MIH prevalence was 17.5% (n = 945). In this group, 9.8% of the children showed hypersensitivity in at least one tooth; 5.6% of all MIH-affected teeth were hypersensitive. Nearly half of the MIH-affected children (49.7%) presented severe MIH-TNI findings; MIH-TNI 2 was the most frequent finding (39.9%). Regression analyses indicated that demarcated opacities were significantly less likely to be associated with hypersensitivity (aOR = 0.054, p < 0.001). However, enamel breakdown did not show a significant association with hypersensitivity (aOR = 0.853, p = 0.693).

Although MIH was relatively common, overall hypersensitivity rates were low. Demarcated opacities were significantly less prone to hypersensitivity, yet enamel breakdown did not significantly differ from healthy teeth. Further standardised epidemiological research is needed to clarify variations in hypersensitivity rates and explore additional risk factors, e.g., breakdown depth or defect extension.