Defining the Prevalence of Molar Incisor Hypomineralization in Brazil

Is there a rise of prevalence for Molar Incisor Hypomineralization? A meta-analysis of published data

Since Molar Incisor Hypomineralization was first described as a pathologic entity, public perception often suggests a considerable rise in prevalence of the respective disease. Since there are still considerable doubts regarding the etiology and-accordingly-prevention of MIH and respective therapeutic approaches are difficult this question is of considerable clinical and public interest. Accordingly, a systematic literature search in accordance with the PRISMA guidelines for systematic reviews on Medline, Cochrane Database, EMBASE, LILACS, Web of Science, Google scholar, Scopus was performed to retrieve original articles reporting the prevalence of MIH as defined by the European Academy of Pediatric Dentistry (EAPD). From initially 2360 retrieved titles, 344 full texts were assessed for possible inclusion and finally 167 articles of mainly moderate to high quality and based on data of 46'613 individuals were included in the meta-analysis. All studies published before 2001 had to be excluded since it was not possible to align the findings with the EAPD classification. Studies varied considerably regarding cohort size (25 to 23'320, mean 1'235)) and age (5.6-19 y, mean 9.8 y). Over all studies, the weighted mean for the prevalence for MIH was 12.8% (95% CI 11.5%-14.1%) and no significant changes with respect to either publication year or birthyear were found. A sub-analysis of eleven studies reporting on the prevalence in different age groups, however, revealed strong evidence for an increasing prevalence between the years 1992 (3%) and 2013 (13%).Therefore, based on data from cross-sectional studies a possible rise in prevalence of MIH remains unclear. Future prospective large-scale studies under standardized examination conditions with an emphasis on examiner calibration are needed to gain better understanding in the evolution of the prevalence of MIH.

[Effect of molar incisor hypomineralization on oral health-related quality of life in children and adolescents: a systematic review]

Introduction

Hypersensitivity, altered dental appearance and fractures are common problems in molar incisor hypomineralization that generate functional and socio-emotional problems.

Objective

to evaluate the effect of MIH on oral health-related quality of life in children and adolescents.

Materials and methods

A systematic bibliographic search was carried out in electronic databases (Pubmed, Epistemonikos, Dentistry & Oral Sciences Source and Virtual Health Library). Observational studies in English or Spanish conducted between 2016-2022 that evaluated the quality of life of children and adolescents with molar incisor hypomineralization were identified. Most studies were of good methodological quality.

Results

Of 96 identified studies, thirteen were included in the synthesis. The most frequent diagnostic criterion for hypomineralization of molar incisors was the index of the European Academy of Pediatric Dentistry and nine studies reported the severity of the disease. The most widely used scale to measure quality of life was the Child Perception Questionnaire (CPQ). According to the children's perception, the most affected dimensions were "Oral Symptoms" and "Emotional Well-Being", according to the parents they were "Oral Symptoms" and "Functional Limitations". Girls with molar incisor hypomineralization had worse oral health-related quality of life.

Conclusions

The negative effect of molar incisor hypomineralization on children's oral health-related quality of life seems to vary between the perception of parents and children.

The prevalence of molar-incisor hypomineralization: a systematic review and meta-analysis

Molar-Incisor Hypomineralization (MIH) is a qualitative defect of enamel of unknown etiology, affecting one or more permanent molars and may include incisors. This condition is a clinical challenge and its prevalence is still uncertain given the recent increase in research. Thus, we aimed to comprehensively estimate the overall prevalence of MIH and associated characteristics. This systematic review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We searched articles using PubMed, MEDLINE, CENTRAL, Web of Science, SciELO, LILACS and TRIP databases, until July 2021. Heterogeneity and publication bias were computed via I2 test statistics and Egger's significance test, respectively. Random-effects meta-analysis of prevalence were processed. We used the Strength of Recommendation Taxonomy [SORT] to grading the strength of evidence. Overall, 116 observational studies were included, with one study with moderate methodological quality and the remaining of high methodological quality. Subgroup analysis confirmed an influence of not using the 2003 MIH case definition (p = 0.0066). The pooled prevalence of MIH was 13.5% (95% CI 12.0-15.1, I2 = 98.0%). Affected incisors were seen in 36.6% (95% CI 30.0-43.7, I2 = 92.5%) of the cases. Lastly, the prevalence of hypomineralization of the second primary molars was observed in 3.6% of the MIH cases (95% CI 1.9-6.8, I2 = 96.3%). America was the continent with highest prevalence (15.3, 95% CI 12.8-18.3, p < 0.001, I2 = 96.3%) and Asia had the lowest prevalence (10.7, 95% CI 8.5-13.5, p < 0.001, I2 = 98.7%), however no continental differences were found. Sample size and year of publication were slight contributing factors to the heterogeneity in the analysis. Overall, these results were classified with a SORT A recommendation.

Incisor Molar Hypomineralization and Quality of Life: A Population-Based Study with Brazilian Schoolchildren

Aim

To assess the impact of incisor molar hypomineralization (MIH) on oral health-related quality of life (OHRQoL) according to the perception of students and their parents/caregivers.

Materials and Methods

This is a cross-sectional population-based study with 463 Brazilian students aged 11-14 years. OHRQoL was measured using the Child Perceptions Questionnaire (B-CPQ_11-14ISF: 16) applied to students and the short version of the Parental-Caregiver Perceptions Questionnaire (B-P-CPQ) applied to parents/caregivers. The diagnosis of MIH followed the European Academy of Paediatric Dentistry criteria modified in 2019. Caries experience (ICDAS II), malocclusion (DAI), and socioeconomic and demographic factors were assessed as confounding factors for impact on OHRQoL. Cluster analysis was carried out to dichotomize the negative impact into greater and lesser impact. The chi-square test and Poisson regression were performed (p < 0.05) to verify associations between quality of life and MIH, adjusted for confounding variables.

Results

The prevalence of MIH was 10.8%. Multivariate regression demonstrated that caries experience was the only oral disease that impacted OHRQoL according to students' self-perception in the functional limitation domain (PR = 1.82; 95% CI = 1.20-2.77) and in the total questionnaire score (PR = 1.59; 95% CI = 1.00-2.51). However, according to the perception of parents/caregivers, in addition to caries experience, which affected OHRQoL in the oral symptoms (PR = 3.57; 95% CI = 1.71-7.414) and emotional well-being domains (PR = 1.71; 95% CI = 1.08-2.69), as well as in the total B-P-CPQ score (PR = 1.67; 95% CI = 1.01-2.76), malocclusion also affected OHRQoL in the social well-being domain (PR = 1.50; 95% CI = 1.07-2.10) and in the total questionnaire score (PR = 1.54; 95% CI = 1.11-2.15).

Conclusion

According to students and their parents/caregivers' perception, incisor molar hypomineralization did not influence OHRQoL of the studied sample.

Gene-environment interaction in molar-incisor hypomineralization

Molar incisor hypomineralization (MIH) is an enamel condition characterized by lesions ranging in color from white to brown which present rapid caries progression, and mainly affects permanent first molars and incisors. These enamel defects usually occur when there are disturbances during the mineralization or maturation stage of amelogenesis. Both genetic and environmental factors have been suggested to play roles in MIH’s development, but no conclusive risk factors have shown the source of the disease. During head and neck development, the interferon regulatory factor 6 (IRF6) gene is involved in the structure formation of the oral and maxillofacial regions, and the transforming growth factor alpha (TGFA) is an essential cell regulator, acting during proliferation, differentiation, migration and apoptosis. In this present study, it was hypothesized that these genes interact and contribute to predisposition of MIH. Environmental factors affecting children that were 3 years of age or older were also hypothesized to play a role in the disease etiology. Those factors included respiratory issues, malnutrition, food intolerance, infection of any sort and medication intake. A total of 1,065 salivary samples from four different cohorts were obtained, and DNA was extracted from each sample and genotyped for nine different single nucleotide polymorphisms. Association tests and logistic regression implemented in PLINK were used for analyses. A potential interaction between TGFA rs930655 with all markers tested in the cohort from Turkey was identified. These interactions were not identified in the remaining cohorts. Associations (p<0.05) between the use of medication after three years of age and MIH were also found, suggesting that conditions acquired at the age children start to socialize might contribute to the development of MIH.