Molar Incisor Hypomineralization and Periodontitis in Adolescents: A Population‐Based Study

ABSTRACT Aim To investigate the association between molar incisor hypomineralization (MIH) and periodontitis in adolescents. Methods A population‐based study was undertaken of Brazilian adolescents aged 18 and 19 years ( n = 2515). MIH was assessed according to Ghanim's criteria. The outcomes were Periodontitis Indicators, a continuous latent variable estimated on the basis of the common variance shared by the indicators bleeding on probing (BoP), probing pocket depth (PPD ≥ 4 mm) and clinical attachment level (CAL ≥ 3 mm), as well as periodontitis cases defined according to CDC‐AAP. Structural equation modelling was used, and the models were adjusted for lower socioeconomic status, sex, smoking, triglycerides/high‐density lipoprotein (TG/HDL) (mg/dL) and visible plaque index. Two other approaches were used for sensitivity analysis: (i) logistic regression, considering the effect of MIH on periodontitis (CDC/AAP) at the individual level, and (ii) multilevel regression to evaluate the association of MIH with CAL and PPD, considering the tooth as the unit of analysis, adjusted for other tooth‐level and individual‐level variables. Results The prevalence of MIH was 16.86% ( n = 423). Individuals with MIH had higher values of the Periodontitis Indicators through a direct pathway (standardized coefficient [SC] = 0.193, p < 0.001) and indirectly mediated by biofilm (SC = 0.263, p < 0.001). MIH was also associated with periodontitis according to CDC‐AAP (SC = 0.071, p < 0.001) and indirectly mediated by biofilm (SC = 0.344, p < 0.001). Consistently, lower socioeconomic status, sex, TG/HDL and biofilm were associated with both periodontal outcomes. Tooth‐level sensitivity regression analysis confirmed the association observed in individual‐level analyses. Conclusion Our findings suggest that adolescents with MIH are susceptible to periodontitis, and it is therefore important to monitor their periodontal health.