Association between molar–incisor hypomineralization and developmental dental anomalies in U.S. children: a cross-sectional study

Objectives To compare the frequency of developmental dental anomalies (DDAs) in children with and without molar–incisor hypomineralization (MIH), and to evaluate whether any association is independent of demographic factors. Materials and methods This comparative cross-sectional study included children aged 6–14 years with and without MIH. Demographic data were collected by structured maternal questionnaire. MIH was diagnosed by calibrated examiners using a validated MIH Index. DDAs were assessed on panoramic radiographs by a blinded examiner using predefined criteria. Group comparisons used Fisher’s exact test (two-sided), and multivariable logistic regression estimated adjusted odds ratios (aORs) with 95% confidence intervals (CIs), adjusting for country of birth, sex, and ethnicity. Results In total, 159 children were enrolled. Any DDA was more frequent in the MIH group than in the non-MIH group (​39.5% vs. 13.7%; p < 0.001​). Short root anomaly (14.0% vs. 1.4%; p = 0.003) and taurodontism (7.4% vs. 0.0%; p = 0.031) were also more frequent with MIH, whereas microdontia of the maxillary lateral incisors was more frequent numerically but not significantly (5.8% vs. 0.0%; p = 0.063). MIH remained independently associated with any DDA in multivariable analysis (aOR = 4.52; 95% CI: 1.97–10.33; p < 0.001). Conclusions Children with MIH had greater odds of concurrent DDAs than children without MIH, most often short root anomaly. Individual anomaly estimates were imprecise owing to few events. Clinical relevance Children with MIH may present with concurrent DDAs, highlighting the potential value of comprehensive clinical assessment and appropriate radiographic evaluation when clinically indicated.