Gene-environment interaction in molar-incisor hypomineralization

Dentin hypersensitivity and toothache among patients diagnosed with Molar-Incisor Hypomineralization: A systematic review and meta-analysis

OBJECTIVES

To determine the prevalence of dentin hypersensitivity (DH) and toothache in patients with Molar-Incisor Hypomineralization (MIH); and evaluate whether patients with MIH have greater likelihood of presenting DH/toothache than controls.

DATA

Studies evaluating DH/toothache in patients with MIH were included. Studies focusing on other enamel defects were excluded.

SOURCES

Eight databases, including grey literature, were searched in January 2024.

STUDY SELECTION

The methodological quality of studies was assessed using the Joanna Briggs Institute checklist for Cross-sectional studies. Proportion and association meta-analyses, subgrouped by diagnostic methods, were conducted. The certainty of evidence was assessed using GRADE approach.

RESULTS

Fifteen studies were included in the qualitative analysis and fourteen in the meta-analyses. Two studies fulfilled all items of the methodological quality checklist. The overall prevalence of DH/toothache among patients with MIH was 45 %. Prevalence rates of 30 %, 47 %, and 55 % were estimated based on proxy reports, self-reports, and air stimulation, respectively. The overall prevalence of DH/toothache per tooth was 22 %, ranging from 16 % to 29 % according to the diagnostic method. Patients with MIH demonstrated higher likelihood of presenting proxy reports of DH/toothache compared to those without MIH (OR: 1.51, 95 % CI [1.23-1.85], P < 0.01, I2: 0 %). The certainty of evidence was very low, mainly due to the low methodological quality of included studies and high inconsistency.

CONCLUSIONS

The global prevalence of DH/toothache was 22 %, per tooth, and 45 % per patient. Estimates vary according to diagnostic methods. Patients with MIH showed higher likelihood of presenting proxy reports of DH/toothache than controls.

CLINICAL SIGNIFICANCE

This systematic review contributes valuable information to the dental literature by assessing the prevalence and associated factors of DH/toothache in patients with MIH. The findings can guide future research, inform clinical practices and public policy makers, and ultimately improve the management of oral health of patients with MIH.

REGISTRATION

PROSPERO CRD42023432805.

Association between molar hypomineralization, genes involved in enamel development, and medication in early childhood: A preliminary study

BACKGROUND

Molar hypomineralization (MH) is defined as a multifactorial condition, and thus, its presence may be defined by interactions between environmental and genetic factors.

AIM

To evaluate the association between MH, genes involved in enamel development, and the use of medication during pregnancy in early childhood.

DESIGN

One hundred and eighteen children, 54 with and 64 without MH, were studied. The data collected included demographics, socioeconomic data, and the medical history of mothers and children. Genomic DNA was collected from saliva. Genetic polymorphisms in ameloblastin (AMBN; rs4694075), enamelin (ENAM; rs3796704, rs7664896), and kallikrein (KLK4; rs2235091) were evaluated. These genes were analyzed by real-time polymerase chain reaction using TaqMan chemistry. The software PLINK was used to compare allele and genotype distributions of the groups and to assess the interaction between environmental variables and genotypes (p < .05).

RESULTS

The variant allele KLK4 rs2235091 was associated with MH in some children (odds ratio [OR]: 3.75; 95% confidence interval [CI] = 1.65-7.81; p = .001). Taking medications in the first 4 years of life was also associated with MH (OR: 2.94; 95% CI = 1.02-6.04; p = .041) and specifically in association with polymorphisms in ENAM, AMBN, and KLK4 (p < .05). The use of medications during pregnancy was not associated with MH (OR: 1.37; 95% CI = 0.593-3.18; p = .458).

CONCLUSION

The results of this study suggest that taking medication in the postnatal period appears to contribute to the etiology of MH in some evaluated children. There may be a possible genetic influence of polymorphisms in the KLK4 gene with this condition.

Potential Association of Molar-Incisor Hypomineralization (MIH) with Dental Agenesis and Infraoccluded Deciduous Molars: Is MIH Related to Dental Anomaly Pattern (DAP)? An Observational Cross-Sectional Study

Background: Dental Anomaly Pattern (DAP) is a collection of morphologic, numeric, and eruptive anomalies of teeth that are often observed together, suggesting a potential genetic relationship. Our objective was to assess the potential associations of Molar-Incisor Hypomineralization (MIH), a common developmental defect of enamel mineralization with a controversial etiology, with two specific components of DAP: (1) agenesis (AG) and (2) infraoccluded deciduous molars (IODM). Establishing such an association between MIH and one or both anomalies would provide evidence supporting a genetic link between MIH and DAP. Methods: We examined pretreatment intraoral standardized photographies and panoramic radiographs from 574 children aged 8-14 years, 287 having MIH and 287 without MIH, comparing the frequencies of AG and IODM in both groups. The subject samples were sourced from the databases of the orthodontic department at a university hospital. Results: The frequencies of AG in the MIH and non-MIH groups were 7% and 8%, respectively (p = 0.751). The corresponding frequencies of IODM were 27% and 19.2%, respectively (p = 0.082). That is, children with MIH did not exhibit an increased frequency of AG or IODM compared to those without MIH. Conclusions: These findings do not support the inclusion of MIH in DAP. Nevertheless, further analysis of possible associations is necessary to definitively validate or invalidate this hypothesis.

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.

Pre- and perinatal exposures associated with molar incisor hypomineralization: Birth cohort, Brazil

OBJECTIVE

To analyze prenatal and perinatal stressors associated with molar incisor hypomineralization (MIH) in adolescents.

METHODS

Prospective cohort study collected prenatal (socioeconomic status, maternal age, number of prenatal visits, smoking, obesity during pregnancy, abortion history, gestational hypertension) and perinatal stressors (type of delivery, gestational age, birth weight, intensive care unit-ICU at birth). The outcome was MIH at 18-19 years follow-up (n = 590). MIH was defined according to the Ghanim criteria - Model I. We performed a sensitivity analysis, including opacities demarcated in index tooth, incisive or molars, Model II. Through structural equation modeling, we analyzed direct and mediating pathways between multiple stressors with outcomes.

RESULTS

MIH was observed in 15.25% (n = 90), and opacities demarcated in any index tooth were observed in 22.8% of adolescents (n = 135). In Model I, no stressor explained MIH significantly, although we watched high standardized coefficients (SC) for low birth weight (SC = 0.223, p = 0.147), lower gestational age (SC = 0.351; p = 0.254), and ICU admission (SC = 0.447, p = 0.254). In Model II, advanced maternal age (SC = 0.148; p < 0.05) and not undergoing prenatal care (SC = 0.384, p < 0.03) explained opacities demarcated in incisors or molars.

CONCLUSION

Advanced maternal age and not undergoing prenatal care were associated with MIH lesion-like in incisors or molars.

Is there an association between molar incisor hypomineralization and developmental dental anomalies? A case-control study

BACKGROUND

The aim of this study was to determine whether there is any association between molar incisor hypomineralization and developmental dental anomalies.

METHODS

Two pediatric dentists evaluated panoramic radiographs of 429 children aged 8-14 years with molar incisor hypomineralization (study group) and 437 children without molar incisor hypomineralization (control group) in terms of developmental dental anomalies. Twelve different developmental dental anomalies were categorized into four types: size (microdontia, macrodontia); position (ectopic eruption of maxillary permanent first molars, infraocclusion of primary molars); shape (fusion, gemination, dilaceration, taurodontism, peg-shaped maxillary lateral incisors); and number (hypodontia, oligodontia, hyperdontia) anomalies.

RESULTS

No significant difference was observed in the frequencies of developmental dental anomalies between the study and control groups in total, females, and males (p > 0.05). A statistically significant difference was found between the distribution of developmental size, position, shape, and number anomalies between the study and control groups (p = 0.024). The most common anomaly in both groups was hypodontia (6.3% and 5.9%, respectively). There was a significant difference between the study and control groups in terms of subtypes of shape anomaly in all children and females (p = 0.045 and p = 0.05, respectively).

CONCLUSIONS

While a significant difference was observed between the distributions of types of developmental dental anomalies between individuals with and without molar incisor hypomineralization, there was no difference in terms of the frequency of developmental dental anomalies.

Biomimetic hydroxyapatite paste for molar-incisor hypomineralization: A randomized clinical trial

OBJECTIVES

The aim of this randomized clinical trial was to evaluate the desensitizing and remineralizing effect of a new zinc-hydroxyapatite-based paste in sites affected by molar-incisor hypomineralization (MIH), by assessing dental sensitivity, tooth wear, and periodontal indexes.

MATERIALS AND METHODS

Twenty-five patients with presence of 1 enamel demineralization of permanent molars and incisors in two different quadrants were recruited. After professional dental hygiene, a domiciliary hydroxyapatite-based paste was assigned and recommended to be applied on 2 MIH teeth in one random quadrant (test group), while the 2 contralateral MIH teeth did not undergo paste application (control group). The following primary outcomes were assessed: Plaque Control Record (PCR), Bleeding Index (BI), MIH Treatment Need Index (MIH-TNI), and Schiff Air Index (SAI).

RESULTS

No significant inter- and intragroup differences were found for PI and BI, except for both intragroup T0-T1. For MIH-TNI, significant intergroup differences were detectable in the test group after 9 months of treatment. For SAI values, no significant differences were found in the control group, while in the test group, significant lower values were found after 1 and 3 months since baseline, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Biomimetic zinc-hydroxyapatite showed a desensitizing effect when used to treat MIH.

Multi-scale characterization of Developmental Defects of Enamel and their clinical significance for diagnosis and treatment

Developmental Defects of Enamel (DDE) such as Dental Fluorosis (DF) and Molar Incisor Hypomineralization (MIH) are a major public health problem. Their clinical aspects are extremely variable, challenging their early and specific diagnosis and hindering progresses in restorative treatments. Here, a combination of macro-, micro- and nano-scale structural and chemical methods, including, among others, Atom Probe Tomography recently applied on tooth enamel, were used to study and compare MIH, DF and healthy teeth from 89 patients. Globally, we show that DF is characterized by an homogenous loss of mineral content and crystallinity mainly disrupting outside layer of enamel, whereas MIH is associated with localized defects in the depth of enamel where crystalline mineral particles are embedded in an organic phase. Only minor differences in elemental composition of the mineral phase could be detected at the nanoscale such as increased F and Fe content in both severe DDE. We demonstrate that an improved digital color measurement of clinical relevance can discriminate between DF and MIH lesions, both in mild and severe forms. Such discriminating ability was discussed in the light of enamel composition and structure, especially its microstructure, organics presence and metal content (Fe, Zn). Our results offer additional insights on DDE characterization and pathogenesis, highlight the potentiality of colorimetric measurements in their clinical diagnosis and provide leads to improve the performance of minimally invasive restorative strategies. STATEMENT OF SIGNIFICANCE: Developmental Defects of Enamel (DDE) are associated to caries and tooth loose affecting billions of people worldwide. Their precise characterization for adapted minimally invasive care with optimized materials is highly expected. Here In this study, first we propose the use of color parameters measured by a spectrophotometer as a means of differential clinical diagnosis. Second, we have used state-of-the-art techniques to systematically characterize the structure, chemical composition and mechanical optical properties of dental enamel teeth affected by two major DDE, Dental Fluorosis (DF) or Molar Incisor Hypomineralization (MIH). We evidence specific enamel structural and optical features for DF and MIH while chemical modifications of the mineral nanocrystals were mostly correlated with lesion severity. Our results pave the way of the concept of personalized dentistry. In the light of our results, we propose a new means of clinical diagnosis for an adapted and improved restoration protocol for these patients.

Bacterial Community Modifies Host Genetics Effect on Early Childhood Caries

By age 5, approximately one-fifth of children have early childhood caries (ECC). Both the oral microbiome and host genetics are thought to influence susceptibility. Whether the oral microbiome modifies genetic susceptibility to ECC has not been tested. We test whether the salivary bacteriome modifies the association of a polygenic score (PGS, a score derived from genomic data that summarizes genetic susceptibility to disease) for primary tooth decay on ECC in the Center for Oral Health Research in Appalachia 2 longitudinal birth cohort. Children were genotyped using the Illumina Multi-Ethnic Genotyping Array and underwent annual dental examinations. We constructed a PGS for primary tooth decay using weights from an independent, genome-wide association meta-analysis. Using Poisson regression, we tested for associations between the PGS (high versus low) and ECC incidence, adjusting for demographic characteristics (n = 783). An incidence-density sampled subset of the cohort (n = 138) had salivary bacteriome data at 24 mo of age. We tested for effect modification of the PGS on ECC case status by salivary bacterial community state type (CST). By 60 mo, 20.69% of children had ECC. High PGS was not associated with an increased rate of ECC (incidence rate ratio, 1.09; 95% confidence interval [CI], 0.83-1.42). However, having a cariogenic salivary bacterial CST at 24 mo was associated with ECC (odds ratio [OR], 7.48; 95% CI, 3.06-18.26), which was robust to PGS adjustment. An interaction existed between the salivary bacterial CST and the PGS on the multiplicative scale (P = 0.04). The PGS was associated with ECC (OR, 4.83; 95% CI, 1.29-18.17) only among individuals with a noncariogenic salivary bacterial CST (n = 70). Genetic causes of caries may be harder to detect when not accounting for cariogenic oral microbiomes. As certain salivary bacterial CSTs increased ECC risk across genetic risk strata, preventing colonization of cariogenic microbiomes would be universally beneficial.

Contemporary Understanding of the Etiology and Management of Molar Incisor Hypomineralization: A Literature Review

Molar incisor hypomineralization (MIH) is a significant health problem that can affect the child's quality of life by negatively affecting their esthetics and function. This review aimed to summarize the etiology and pathogenesis of MIH. It also aimed to summarize the recent studies on MIH in children and adolescents, focusing on diagnosis, prevention, and clinical management. An electronic search on the PubMed, Cochrane Database of Systematic Reviews, MEDLINE, MedlinePlus, WHO reports, and Google Scholar databases was performed. The volume of research on the etiology, presentation, and clinical management of MIH is still expanding. The creation and validation of indices for the diagnosis and management of MIH, as well as any potential genetic aspects appear to be the main areas of current research. Notably, MIH was linked to childhood illnesses, the use of antibiotics, and early childhood fever. Although many studies discuss the different options for managing MIH lesions, evidence-based studies that address the long-term outcomes of MIH are still lacking. Indeed, future clinical studies should be directed to evaluate the impact of each systemic etiological factor and its different types of management on normal amelogenesis. Regarding the diagnosis, future research should focus on the pre-eruption diagnosis and early approaches to prevent the post-eruption breakdown and caries. Regarding the treatment of MIH, future investigations should emphasize further improvements in adhesion and the use of new materials and techniques, such as digital dentistry.

Association between genetic factors and molar-incisor hypomineralisation or hypomineralised second primary molar: A systematic review

OBJECTIVE

To determine the association between genetic factors and molar-incisor hypomineralisation (MIH) and/or hypomineralised second primary molars by means of a systematic review.

DESIGN

A search was performed in Medline-PubMed, Scopus, Embase and Web of Science databases; manual search and search in gray literature were also performed. Selection of articles was performed independently by two researchers. A third examiner was involved in cases of disagreement. Data extraction was performed using an Excel® spreadsheet and independent analysis was performed for each outcome.

RESULTS

Sixteen studies were included. There was an association between MIH and genetic variants related to amelogenesis, immune response, xenobiotic detoxification and other genes. Moreover, interactions between amelogenesis and immune response genes, and SNPs in the aquaporin gene and vitamin D receptors were associated with MIH. Greater agreement of MIH was found in pairs of monozygotic twins than dizygotic twins. The heritability of MIH was 20 %. Hypomineralised second primary molars was associated with SNPs in the hypoxia-related HIF-1 gene and methylation in genes related to amelogenesis.

CONCLUSION

With very low or low certainty of evidence, an association was observed between MIH and SNPs in genes associated with amelogenesis, immune response, xenobiotic detox and ion transport. Interactions between genes related to amelogenesis and immune response as well as aquaporin genes were associated to MIH. With very low certainty of evidence, hypomineralised second primary molars was associated to a hypoxia-related gene and to methylation in genes related to amelogenesis. Moreover, higher agreement of MIH in pairs of monozygotic twins than dizygotic twins was observed.

Bacterial community modifies host genetics effect on early childhood caries

Background

By age five approximately one-fifth of children have early childhood caries (ECC). Both the oral microbiome and host genetics are thought to influence susceptibility. Whether the oral microbiome modifies genetic susceptibility to ECC has not been tested. We test whether the salivary bacteriome modifies the association of a polygenic score (PGS, a score derived from genomic data that summarizes genetic susceptibility to disease) for primary tooth decay on ECC in the Center for Oral Health Research in Appalachia 2 longitudinal birth cohort.

Methods

Children were genotyped using the Illumina Multi-Ethnic Genotyping Array and underwent annual dental examinations. We constructed a PGS for primary tooth decay using weights from an independent, genome-wide association meta-analysis. Using Poisson regression, we tested for associations between the PGS (high versus low) and ECC incidence, adjusting for demographic characteristics (n=783). An incidence-density sampled subset of the cohort (n=138) had salivary bacteriome data at 24- months of age. We tested for effect modification of the PGS on ECC case status by salivary bacterial community state type (CST).

Results

By 60-months, 20.69% of children had ECC. High PGS was not associated with an increased rate of ECC (incidence-rate ratio:1.09 (95% confidence interval (CI): 0.83, 1.42)). However, having a cariogenic salivary bacterial CST at 24-months was associated with ECC (odds ratio (OR): 7.48 (95%CI: 3.06, 18.26)), which was robust to PGS adjustment. An interaction existed between the salivary bacterial CST and the PGS on the multiplicative scale (P= 0.04). The PGS was associated with ECC (OR: 4.83 (95% CI: 1.29, 18.17)) only among individuals with a noncariogenic salivary bacterial CST (n=70).

Conclusions

Genetic causes of caries may be harder to detect when not accounting for cariogenic oral microbiomes. As certain salivary bacterial CSTs increased ECC-risk across genetic-risk strata, preventing colonization of cariogenic microbiomes would be universally beneficial.

Enamel Phenotypes: Genetic and Environmental Determinants

Dental enamel is a specialized tissue that has adapted over millions of years of evolution to enhance the survival of a variety of species. In humans, enamel evolved to form the exterior protective layer for the crown of the exposed tooth crown. Its unique composition, structure, physical properties and attachment to the underlying dentin tissue allow it to be a resilient, although not self-repairing, tissue. The process of enamel formation, known as amelogenesis, involves epithelial-derived cells called ameloblasts that secrete a unique extracellular matrix that influences the structure of the mineralizing enamel crystallites. There are over 115 known genetic conditions affecting amelogenesis that are associated with enamel phenotypes characterized by either a reduction of enamel amount and or mineralization. Amelogenesis involves many processes that are sensitive to perturbation and can be altered by numerous environmental stressors. Genetics, epigenetics, and environment factors can influence enamel formation and play a role in resistance/risk for developmental defects and the complex disease, dental caries. Understanding why and how enamel is affected and the enamel phenotypes seen clinically support diagnostics, prognosis prediction, and the selection of treatment approaches that are appropriate for the specific tissue defects (e.g., deficient amount, decreased mineral, reduced insulation and hypersensitivity). The current level of knowledge regarding the heritable enamel defects is sufficient to develop a new classification system and consensus nosology that effectively communicate the mode of inheritance, molecular defect/pathway, and the functional aberration and resulting enamel phenotype.

Prevalence of and factors associated with molar-incisor hypomineralisation in schoolchildren in the canton of Basel-Landschaft, Switzerland

OBJECTIVES

As prevalence of molar-incisor hypomineralisation varies considerably in different countries and regions, the aim of this study was to obtain representative epidemiological data for schoolchildren living in the canton of Basel-Landschaft, Switzerland.

MATERIAL AND METHODS

A representative population of schoolchildren of three different age groups, i.e. 1st grade (mean age: 7.4 years), 6th grade (mean age: 12.6 years), and 9th grade (mean age: 15.7 years) visiting compulsory schools in the canton of Basel-Landschaft, Switzerland, was examined. The presence or absence of molar-incisor hypomineralisation at time of examination was recorded as well as potential influencing factors such as age group, gender, nationality, or the children's place of residence.

RESULTS

A total of 1252 schoolchildren could be included. On average, the prevalence of MIH in the study population was 14.8%. No statistically significant differences were found for nationality, gender, or place of residence. Although not statistically significant, children from the youngest age group had the highest while children from the oldest age group had the lowest MIH prevalence.

CONCLUSION

With a mean value of 14.8%, MIH prevalence among schoolchildren living in the canton of Basel-Landschaft, Switzerland, is comparable to mean values recorded globally.

CLINICAL RELEVANCE

This study represents the first study on MIH prevalence in Switzerland and also provides further evidence on potential influencing factors.

How is the quality of the available evidence on molar-incisor hypomineralization treatment? An overview of systematic reviews

OBJECTIVE

This overview analyzed the quality of the systematic reviews (SRs) available on treatments for molar-incisor hypomineralization (MIH).

MATERIAL AND METHODS

Six electronic databases were searched (PubMed/MEDLINE, Scopus, Web of Science, LILACS, Brazilian Bibliography of Dentistry and Cochrane Library) until March 2022. Two reviewers independently performed the selection, the quality assessment (Assessment of Multiple Systematic Reviews 2 - AMSTAR-2), and the risk of bias assessment of the SR (Risk of Bias in Systematic Reviews - ROBIS).

RESULTS

Two hundred nine records were retrieved; after removing duplicates and applying the inclusion/exclusion criteria, 5 SRs remained. Three SRs were rated as showing critically low methodological quality and high risk of bias, and two were rated as moderate methodological quality and low risk of bias. The identified treatments that may be suitable for MIH were classified as (1) non-invasive - casein incorporated into toothpaste and sugar-free chewing gum, toothpaste containing arginine, 0.4% stannous fluoride gel; fluoride varnish; (2) micro-invasive - resin sealants for pits and fissures, microabrasion, dental whitening, resin infiltration; (3) invasive - ART restorations, indirect restorations (metal, composite, or ceramic); and (4) mixed intervention - stainless steel crowns.

CONCLUSION

Despite the considerable number of published papers included in this set of systematic reviews, the evidence supporting the effectiveness of treatments for treating MIH is limited due to the methodological quality and risk of bias of the systematic reviews, as well as the quality of the primary studies (PROSPERO: CRD42020144831).

CLINICAL RELEVANCE

Different treatments have been purposed for MIH treatment, but there is still not enough scientific evidence of good quality for the establishment of a definitive clinical protocol for the treatment of MIH.

Virtual learning object for developing knowledge about the diagnosis and management of molar incisor hypomineralization

AIM

To develop, apply, and evaluate a virtual learning object (VLO) for teaching undergraduate dental students and paediatric dentists to diagnose and manage molar incisor hypomineralization (MIH).

DESIGN

This controlled educational intervention included 170 undergraduate dental students and 50 paediatric dentists. The student intervention group (VLOG) was trained by the VLO, the control group of students (CG) received a synchronous virtual class, and the group of paediatric dentists (PDG) was trained by the VLO. Pre-test and post-test data were analyzed with a mixed one-way and Tukey's post hoc ANOVA test (α = 0.05). The answers to the questionnaire were analyzed with the one-way ANOVA test and Tukey's post hoc test (α = 0.05).

RESULTS

The values obtained in the pre-test were significantly lower than those obtained in the post-test for all groups. The specialists showed a higher level of knowledge before and after the MIH training compared with the students (p < .001). Similarly, statistical differences were found in the level of knowledge, which increased after MIH training (p < .001). There were no differences between the CG and VLOG.

CONCLUSIONS

The level of knowledge increased in all groups after training regardless of the method used. VLOG works similar to traditional teaching approaches.

Molar-incisor hypomineralisation: an updated view for aetiology 20 years later

BACKGROUND

The term Molar-Incisor Hypomineralisation (MIH) was introduced in 2001 by Weerheijm, Jälevik and Alaluusua, and describes a defect of systemic origin that affects one to four first permanent molars, often associated with permanent incisors. In the past 20 years, this definition dictated the work regarding MIH prevalence, associated risk factors, association with dental caries, impact on quality of life, and therapeutic options.

PURPOSE

In this report, we offer an updated and comprehensive view of MIH centred on the patient and the tooth.

CONCLUSION

MIH today is globally recognized as a potential public health problem and it is not a defect of purely systemic origin but rather a condition with complex aetiology that in some instances may be the result of gene-environmental interactions.

[Molar incisor hypomineralisation (MIH)-discussion of prevalence and etiology with special reference to the results from the Munich birth cohorts GINIplus and LISA]

After caries, molar incisor hypomineralisation (MIH)-also known as chalky teeth-is one the most common dental diseases in children and adolescents. In addition to aesthetic limitations, especially on the anterior teeth, hypersensitivities and enamel breakdowns on permanent molars are of functional importance. While the MIH prevalence rates range from ~ 10% to ~ 30% and is well described, the situation regarding aetiology is unsatisfactory. Although efforts have been made in the past to clarify the aetiology, no plausible reason is available so far. Aetiology research has to be judged as methodologically challenging, since it should ideally be embedded in prospectively planned birth cohort studies. The aim of this article is to summarize typical clinical characteristics of MIH, epidemiological findings and potential causes with special reference to the earlier published results from the two Munich birth cohort studies GINIplus and LISA.

Assessment of Genetical, Pre, Peri and Post Natal Risk Factors of Deciduous Molar Hypomineralization (DMH), Hypomineralized Second Primary Molar (HSPM) and Molar Incisor Hypomineralization (MIH): A Narrative Review

Objectives: Analyze defects in the state of maturation of the enamel result in an adequate volume of enamel, but in an insufficient mineralization, which can affect both deciduous teeth and permanent teeth. Among the most common defects, we recognize Deciduous Molar Hypominerlization (DMH), Hypomineralized Second Primary Molar (HSPM), and Molar Incisor Hypomineralization (MIH). These, in fact, affect the first deciduous molars, the second deciduous molars and molars, and permanent incisors, respectively, but their etiology remains unclear. The objective of the paper is to review studies that focus on investigating possible associations between genetic factors or prenatal, perinatal, and postnatal causes and these enamel defects. Materials and methods: A comprehensive and bibliometric search for publications until January 2021 was conducted. The research question was formulated following the Population, Intervention, Comparison, Outcome strategy. Case-control, cross-sectional, cohort studies, and clinical trials investigating genetic and environmental etiological factors of enamel defects were included. Results: Twenty-five articles are included. For genetic factors, there is a statistical relevance for SNPs expressed in the secretion or maturation stage of amelogenesis (16% of studies and 80% of studies that investigated these factors). For prenatal, perinatal, and postnatal causes, there is a statistical relevance for postnatal factors, such as the breastfeeding period (2%), asthma (16%), high fever episodes (20%), infections/illnesses (20%), chickenpox (12%), antibiotic intake (8%), diarrhea (4%), and pneumonia (4%). Conclusions: The results are in agreement with the multifactorial idea of the dental enamel defects etiology, but to prove this, further studies enrolling larger, well-diagnosed, and different ethnic populations are necessary to expand the investigation of the genetic and environmental factors that might influence the occurrence of DMH, HPSM, and MIH.