RESUMEN
BACKGROUND: The etiology of molar-incisor hypomineralization (MIH) remains unknown. Studies indicate that it is multifactorial, and that genetic and environmental factors are involved. Research with twins provides important subsidy to investigate the Influence of genetics and environmental factors that act during pregnancy on the etiology of alterations. AIM: This cross-sectional study evaluated the agreement of molar incisor hypomineralization (MIH) between monozygotic and dizygotic twin pairs and the association with environmental factors. DESIGN: The sample consisted of 167 pairs of twins (8-15 years old), 94 monozygotic and 73 dizygotic. The parents answered a questionnaire on sociodemographic data and pre-, peri-, and postnatal health. A dental examination was performed by two calibrated examiners (Kappa ≥0.88) for MIH diagnosis, following the criteria proposed by the European Academy of Pediatric Dentistry in 2003. RESULTS: The prevalence of MIH was 29.3%. There was greater concordance of MIH between monozygotic twins for affected first molars and permanent incisors (P = 0.0012) and pairs of twins assessed (P = 0.0211). The presence of MIH was associated with family income between one and two wages (P = 0.009, prevalence ratio [PR] = 3.82, confidence interval [CI 95%] 1.40-10.44), above two wages (P = 0.007, PR = 4.60, 95% CI: 1.51-14.05), and gestational hemorrhage (P = 0.032, PR = 5.70, 95% CI: 1.16-28.14). CONCLUSIONS: The greater concordance in the diagnosis of MIH among monozygotic twins indicates a genetic influence, although environmental factors, such as family income and hemorrhage during pregnancy, are also associated with the occurrence of MIH.
Asunto(s)
Hipoplasia del Esmalte Dental/etiología , Adolescente , Brasil/epidemiología , Niño , Estudios Transversales , Hipoplasia del Esmalte Dental/epidemiología , Hipoplasia del Esmalte Dental/genética , Enfermedades en Gemelos/epidemiología , Enfermedades en Gemelos/etiología , Enfermedades en Gemelos/genética , Femenino , Humanos , Masculino , Prevalencia , Factores de Riesgo , Factores Socioeconómicos , Encuestas y Cuestionarios , Gemelos Dicigóticos/estadística & datos numéricos , Gemelos Monocigóticos/estadística & datos numéricosRESUMEN
PURPOSE: To determine the prevalence of molar-incisor hypomineralization (MIH) in children and possible factors associated with this disorder. METHODS: This was a cross-sectional observational study of 594 11- to 14-year-olds from Teresina, Piauí, Brazil. The diagnosis of MIH was made based on criteria set by the European Academy of Pediatric Dentistry. To investigate possible associated factors, mothers completed a questionnaire. A descriptive analysis of the data, chi-square, Mann-Whitney, and Fisher tests and Poisson regression (PR) were performed. RESULTS: The prevalence of MIH was 18.4 percent (95 percent confidence interval [CI] equals 15.20 to 21.50). The maxillary molars were the teeth most affected by MIH (36.1 percent). MIH patients showed a higher number of mean DMF-T (PR equals 2.18; 95 percent CI equals 1.46 to 2.85) than those not affected by the condition. There was an association between MIH and preterm birth (PR equals 1.76; 95 percent CI equals 1.22 to 2.12) and between MIH and respiratory distress at birth (PR equals 1.83; 95 percent CI equals 1.25 to 2.18). CONCLUSIONS: The prevalence of MIH in schoolchildren was 18.4 percent. Those with MIH had a greater mean DMF-T than those without MIH. Preterm birth and respiratory distress were associated with MIH.