MOLAR INCISOR HYPOMINERALISATION AMONG 12-YEAR-OLDS IN NORTHWEST RUSSIA

Abstract

Introduction: Although there is a considerable amount of evidence on molar incisor hypomineralisation originating from developed countries, the evidence from Russia is almost non-existent.

Aim: To estimate the prevalence of molar incisor hypomineralisation (MIH) across genders and place of residence as well as its association with dental caries among 12-years-old children in Northwest Russia. Methods: A crosssectional study included 1233 (653 girls) randomly selected 12-years-old children from seven urban and five rural areas of the Arkhangelsk region. MIH and its severity were diagnosed using Weerheijm et al. (2003) and Mathu- Muju &Wright (2006) criteria, respectively. Dental caries was studied by two calibrated examiners at the D3 level following WHO (2013) recommendations. By place of residence all participants were dichotomised into urban and rural residents. Prevalence of MIH and caries and means for Decayed-Missing- Filled (DMFT) scores are presented with 95% confidence intervals (CI). Pearson’s chi-squared tests and Mann- Whitney tests were used for dichotomous and numerical data, respectively. The study was approved by the Ethical Committee of the Northern State Medical University, Arkhangelsk, Russia. Informed consent was obtained from all parents.

Results: The overall prevalence of MIH was 2.1% (95%CI:1.44-3.07) with no difference by gender (p=0.760) or place of residence (p=0.532). The prevalence of mild MIH was 46.2% (95%CI:28.8-64.5). Average and severe MIH were diagnosed in 26.9% (95%CI:13.7-46.1) of children. The prevalence of caries among those with and without MIH was 100% (95%CI: 87.1-100.0) and 74.8% (95%CI: 72.3-77.2), respectively (p=0.003). Mean DMFT values for children with and without MIH were 4.46 (95%CI:3.20-5.72) and 2.45 (95%CI:2.33-2.58), respectively (p<0.001).

Conclusions: Although the prevalence of MIH in Northwest Russia is lower than in most other countries the findings of this study suggest that hypomineralised molars are much more prone to caries. No difference across genders or place of residence were observed. The factors behind the main findings will be discussed in the poster.