Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization

Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Cooccurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9-86.6) and the negative predictive value 84.7% (80.6-88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9-17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47-0.68). The odds ratio was 18.2 (9.39-35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH

A comparison of the presentation of molar incisor hypomineralisation in two communities with different fluoride exposure

Aim To compare the clinical presentation of two cohorts of children diagnosed with molar incisor hypomineralisation (MIH) and living in areas of low and high background fluoridation. Methods The study population comprised 12-year-old children participating in the 2008–2009 National Dental Epidemiological Programme in five regions in Northern England. Participating dentists were trained and calibrated in the use of the modified Developmental Defects of Enamel Index. Children were examined at school under direct vision with the aid of a dental mirror. First permanent molars and incisors were recorded for the presence and type of enamel defects greater than 2 mm. A diagnosis of MIH was ascribed to any child with a demarcated defect in any first permanent molar. Risk ratios for the occurrence of demarcated, diffuse and hypoplastic defects were generated for MIH children in the fluoridated and non-fluoridated area. Results 3,233 children were examined. The prevalence of MIH in the fluoridated community was 11 % and in the non-fluoridated community was 17.5 %. Incisors in children with MIH were at greater risk of having demarcated defects (risk ratio 4.0, 3.6–4.5) and diffuse defects (risk ratio 2.2, 2.0–2.5). Molars in children with MIH were at greater risk of diffuse defects (risk ratio 4.4, 3.8–5.0). The teeth of children with MIH living in the fluoridated area were at greater risk of demarcated defects for both incisors (risk ratio 1.6, 1.3–2.0) and molars (risk ratio 1.3, 1.2–1.5) relative to the teeth of MIH children living in the non-fluoridated area. Conclusions Children with MIH were at increased risk of both diffuse and demarcated defects in their incisors. Children with MIH living in the fluoridated area were at increased risk of diffuse and demarcated defects relative to MIH children living in the non-fluoridated area