Prevalence and etiology of molar-incisor hypomineralization (MIH) in the city of Istanbul

Possible Etiological Factors for the Development of Molar Incisor Hypomineralization (MIH) in Austrian Children

BACKGROUND

Molar incisor hypomineralization (MIH) is a developmental enamel defect that primarily affects the first permanent molars and sometimes the incisors. Its increasing prevalence worldwide has raised clinical concerns, yet its exact cause remains unknown. This study aimed to assess potential factors influencing MIH development by analyzing the medical history of children aged 6 to 12 years using a questionnaire.

METHODS

This study included 100 children aged 6-12 years diagnosed with MIH during dental examination, and 100 age-matched children in the non-MIH (healthy) group from the Department of Pediatric Dentistry, University Clinic of Dentistry, Medical University of Vienna. The parents of the participants completed a two-page questionnaire regarding possible etiological factors of MIH.

RESULTS

The data analysis involved 100 children with MIH (mean age 8.5; ±1.3; 52% female) and 100 children in the healthy group (mean age 9.2; ±1.3; 42% female). The optimized binary logistic regression analysis revealed a significant association between MIH development and cesarean-section delivery (OR = 3; CI = [1.5-6.2]) and sixth disease (roseola) (OR = 3.5; CI = [1.5-8.0]).

CONCLUSIONS

This study suggests that cesarean-section delivery and sixth disease (roseola) might increase the likelihood of MIH development in children.

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.

Knowledge and Attitudes of a Group of Dental Students in Turkey About Molar Incisor Hypomineralization

BACKGROUND This study aimed to evaluate the knowledge and attitudes of 4th- and 5th-year students of Dicle University Faculty of Dentistry (Diyarbakır) about molar incisor hypomineralization (MIH). MATERIAL AND METHODS The questionnaires previously used in other countries were modified and the questionnaire forms consisting of 23 questions were distributed to the students online. The results of the analysis are presented as frequencies. The significance level was set as P<0.05. RESULTS A total of 111 4th-year students (51%) and 107 5th-year students (49%) participated in our study. A statistically significant difference was found between the 4th-year students (68.5%) and the 5th-year students (98.1%) in terms of having heard of the term MIH before (P<0.001). While most students reported knowing the clinical features of MIH, only 26.1% were confident in their diagnosis. A statistically significant difference was found between the 4th- and 5th-year students who thought that MIH was a clinical problem, in the distribution of those who had problems both in terms of aesthetics, and in providing adequate restoration (P=0.012). CONCLUSIONS Although most of the students were theoretically familiar with MIH, they were not confident in their diagnosis and found it difficult to differentiate MIH from other dental anomalies. However, the awareness of 5th-year dental students was better than that of the 4th-year students.

The Prevalence of Developmental Enamel Defects in Israeli Children and Its Association with Perinatal Conditions: A Cross-Sectional Study

Molar incisor hypomineralization (MIH) and deciduous molar hypomineralization (DMH) affect the first permanent molars and second primary molars, respectively, causing a greater dental treatment burden and worse oral health quality of life among affected children. We assessed the prevalence and risk factors of MIH and DMH among 1209 children aged 3-13 years who attended a university dental clinic in Israel in 2019-2020. Clinical examinations were conducted to assess the presence of DMH and MIH. Potential etiological factors of MIH and DMH, including demographics, the mother's perinatal health, and the child's medical history during the first three years of life, were retrieved using a questionnaire. To examine the associations between the demographic and clinical variables and the prevalence of MIH and DMH, continuous variables were tested using the Kruskal-Wallis test with Bonferroni corrections. Categorical variables were analyzed by chi-squared test. Multivariate logistic regression was conducted to evaluate which of the significant variables found in the univariate analysis could predict a diagnosis of both MIH and DMH. The prevalence of MIH and DMH was 10.3% and 6.0%, respectively. Age ≥ 5 years, taking medications during pregnancy and severe lesions were associated with a greater risk for a diagnosis of DMH + MIH. Multivariate logistic regression with adjustment for age showed that the severity of hypomineralization was positively and significantly associated with a diagnosis of MIH + DMH with an odds ratio of 4.18 (95% confidence interval 1.26-17.16), p = 0.03. MIH should be diagnosed and monitored in young children to prevent further deterioration. Moreover, a preventive and restorative program for MIH should be established.

Etiological Factors of Molar Incisor Hypomineralization: A Systematic Review and Meta-Analysis

Molar incisor hypomineralization (MIH) is a defect of the dental enamel that predominantly affects first molars and permanent incisors. Identifying the significant risk factors associated with MIH occurrence is essential for the implementation of prevention strategies. The purpose of this systematic review was to determine the etiological factors associated with MIH. A literature search was carried out from six databases until 2022; it covered pre-, peri-, and postnatal etiological factors. The PECOS strategy, PRISMA criteria, and the Newcastle-Ottawa scale were used, and 40 publications were selected for qualitative analysis as well as 25 for meta-analysis. Our results revealed an association between a history of illness during pregnancy (OR 4.03 (95% CI, 1.33-12.16), p = 0.01) and low weight at birth (OR 1.23 (95% CI, 1.10-1.38), p = 0.0005). Furthermore, general illness in childhood (OR 4.06 (95% CI, 2.03-8.11), p = 0.0001), antibiotic use (OR 1.76 (95% CI, 1.31-2.37), p = 0.0002), and high fever during early childhood (OR 1.48 (95% CI, 1.18-1.84), p = 0.0005) were associated with MIH. In conclusion, the etiology of MIH was found to be multifactorial. Children with health disorders in the first years of life and those whose mothers underwent illnesses during pregnancy might be more susceptible to MIH.

A clinical and statistical study on enamel hypomineralization of the first permanent molar in the period of mixed dentition

BACKGROUND

The first permanent molar (FPM) is the first tooth in the permanent dentition that emerges in the oral cavity, at around the age of six and behind the deciduous teeth, thus converting the primary dentition into a mixed dentition. Its early formation represents a risk factor for the onset of hard dental tissues disorders, the most common being the molar incisor hypomineralization (MIH).

AIM

The aim of the study was to assess the hypomineralization type of developmental defects of enamel at FPM level during the mixed dentition stage, in a group of Romanian children.

PATIENTS, MATERIALS AND METHODS

The research was conducted on 87 patients, 44 females and 43 males, divided into the following age groups: 5-6 years, 6-7 years, 7-8 years, 8-9 years, 9-10 years, 10-11 years, 11-12 years and older than 12 years. All children were examined in the dental office by a pediatric dentist.

RESULTS

Of the subjects, 40.2% presented hypomineralization lesions on the FPM. Among the affected children, 62.9% were girls and 37.1% were boys. Mild forms were the most prevalent, being found in 71.4% of the affected subjects. Moderate forms were present in 22.9% and severe forms in 5.7% of the affected children. MIH prevalence significantly decreased with increasing age. Only two children belonging to the group 8-9 years and 10-11 years, respectively, showed severe MIH lesions. Statistically significant differences were determined in what regards the distribution of MIH children according to the severity of the lesions in relation to age (p=0.007).

CONCLUSIONS

Children 6- to 7-year-old have been the most affected by FPM hypomineralization, which indicates the need for early management of the disease, through a thorough diagnosis, and preventive and interceptive therapeutic approaches.

Etiology Study of Acquired Developmental Defects of Enamel and Their Association with Dental Caries in Children between 3 and 19 Years Old from Dolj County, Romania

Background: Developmental defects of enamel (DDE) are frequently encountered in primary and permanent teeth, yet their etiology is not completely known. Enamel hypoplasia is considered a predisposing factor for early caries. The objective of this study was the evaluation of several risk factors potentially causing DDE and the possible association between DDE and dental caries. Methods: This study was performed on a group of 213 rural children from Romania. It combined a thorough dental examination for all children, and a questionnaire filled in by their mothers, regarding the evolution of their pregnancy and the child’s health status in the first years of life. Results: There was no statistically significant association between DDE presence and data regarding the evolution of pregnancy, mothers’ health status or children’s conditions during early childhood. There was a significant association between the use of amoxicillin, ibuprofen, and cephalosporin during the period of formation of permanent teeth, and one environmental factor (water source), and the presence of DDE (Chi Square, p < 0.05). Also, DDEs were associated with the presence of caries (Fisher, p = 0.001). Conclusions: Children who consumed water from private wells and children who received medication during early childhood developed more enamel defects, presenting a higher risk of caries development.

Prevalence and Possible Etiological Factors of Molar-Incisor Hypomineralization (MIH) in Population of Silesian Children in Poland: A Pilot Retrospective Cohort Study

(1) Background: This pilot retrospective cohort research study regarded the frequency of the prevalence of molar-incisor hypomineralization (MIH) in a population of Silesian children in Poland. The evaluation of the potential environmental etiological factors was performed and the correlation between the environmental factors and MIH was analyzed. (2) Methods: A total of 613 children were randomly enrolled in the pilot study (9.0 years ± 1.9). A survey was carried out with mothers regarding the potential exposure to environmental etiological factors of MIH in their children. The patients’ clinical assessments were carried out in the dental unit. (3) Results: The frequency of prevalence of MIH in the population of Silesian children was established at the level of 6.2% (p < 0.05). MIH symptoms were significantly associated with otitis in early childhood (OR = 2.50), atopic dermatitis (OR = 5.69), and premature delivery before 38 weeks of pregnancy (OR = 2.88). (4) Conclusions: MIH was observed in 6.2% of the population of Silesian children, and there was a relationship between environmental risk factors such as otitis, atopic dermatitis, premature birth, and MIH expression. Therefore, further research is needed to determine the influence of pre-, peri-, postnatal, and prophylactic factors on the frequency and severity of MIH symptoms in children.

Molar Incisor Hypomineralization: Prevalence, Associated Risk Factors, Its Relation with Dental Caries and Various Enamel Surface Defects in 8–16-year-old Schoolchildren of Lucknow District

Introduction

Aim

Methodology

Results

Conclusion

Clinical significance

How to cite this article

An update of the aetiological factors involved in molar incisor hypomineralisation (MIH): a systematic review and meta-analysis

PURPOSE

To systematically review the aetiological factors associated with molar incisor hypomineralisation (MIH). To this day, the aetiology remains unknown. Determining risk factors would allow risk assessment and enhance early diagnosis of MIH in young patients. The aim was to assess, evaluate and summarise the relationship between MIH and reported aetiological hypotheses.

METHODS

Electronic database searches of MEDLINE, EMBASE, EBSCO, LILACS and Cochrane Library were conducted. Authors conformed to PRISMA guidelines. Studies were screened, data extracted, assessment of risk of bias and calibration was completed by two independent reviewers. Meta-analyses with heterogeneity calculations were performed.

RESULTS

Of the potential 8949 studies, 64 studies were included in the qualitative analysis whilst 45 were included in the quantitative analysis. Prenatal factors: results are inconclusive as only unspecified maternal illnesses appear to be linked to MIH. Perinatal factors: prematurity (OR 1.45; 95% CI 1.24-1.70; p = 0.0002) and caesarean delivery (OR 1.45; 95% CI 1.09, 1.93; p < 0.00001) are associated with an increased risk of developing MIH. Birth complications are also highlighted. These three factors can lead to hypoxia, and children with perinatal hypoxia are more likely to develop MIH (OR 2.76; 95% CI 2.09-3.64; p < 0.0001). Postnatal factors: measles, urinary tract infection, otitis media, gastric disorders, bronchitis, kidney diseases, pneumonia and asthma are associated with MIH. Fever and antibiotic use, which may be considered as consequences of childhood illnesses, are also associated with MIH. Genetic factors: an increasing number of studies highlight the genetic and epigenetic influences in the development of MIH.

CONCLUSION

Several systemic and genetic and/or epigenetic factors acting synergistically or additively are associated with MIH, revealing a multifactorial aetiology model. Peri- and postnatal aetiological factors are more likely to increase the odds of causing MIH than prenatal factors.

Relationship between molar incisor hypomineralization, intrapartium medication and illnesses in the first year of life

Molar incisor hypomineralization (MIH) affects the first permanent molars and permanent incisors whose formative embryological process develops around birth and the first year of life. This study’s main objective is to assess the relationship between MIH, on the one hand, with the administration during childbirth of epidural bupivacaine, intramuscular meperidine with haloperidol, synthetic intravenous oxytocin, and prostaglandins such as dinoprostone vaginally, and on the other hand, with suffered pathologies during the first year of life. Cross-sectional retrospective study was carried out on 111 children who attended dental check-ups. Oral examination was carried out to determine MIH involvement. Data on the administration of medications during delivery and the illnesses suffered by the children in the first year of life were taken from the hospital records. Significant relationship with Pearson's chi-square was found between the presence of MIH and the administration of meperidine with haloperidol intramuscularly and the vaginal administration of dinoprostone during labour. Also in children who have suffered serious infections and those who have received antibiotics in early childhood. In recent years there has been a growing trend in many countries to medicalize childbirth even above what the World Health Organization recommends. Some of the drugs used in these protocols could be involved in the appearance of dental mineralization alterations of the MIH type and this would help to explain the increase in its prevalence.

Prevalence and possible aetiological factors of molar incisor hypomineralisation in Saudi children: A cross-sectional study

Background

A new charting system for molar incisor hypomineralisation (MIH) was recently published and is based on the European Academy of Paediatric Dentistry (EAPD) criteria. This charting system aims to standardise MIH data collection. Therefore, there is a need for new MIH prevalence studies using the currently recommended charting-form.

Aim

To investigate the prevalence and possible aetiological factors of MIH in randomly selected Saudi schoolchildren aged 8–12 years in Riyadh.

Design

A randomly selected sample of Saudi schoolchildren aged 8–12 years attending elementary schools in Riyadh was examined using the EAPD short-form charting, which was recently recommended for the standardised collection of epidemiological data on MIH. To investigate possible aetiological factors of MIH, we collected demographic, pregnancy, and medical history using a questionnaire.

Results

A total of 1,562 children participated in the study (48.8% girls, 51.2% boys). The prevalence of MIH was 15.2%, without a significant difference in the prevalence between the sexes. Among those with MIH, 79.4% had affected incisors and 55.9% had hypomineralised second primary molars. The most prevalent clinical defect was demarcated opacities, and the maxillary arch was more affected. Permanent incisors were more affected in boys than in girls. Defects of the first permanent molars were more severe in terms of clinical status and lesion extent than defects of the permanent incisors. MIH was significantly more prevalent in children with a history of early childhood ear infections, respiratory distress, and tonsillitis.

Conclusions

MIH is common in Saudi schoolchildren living in Riyadh, with no gender predilection. Hypomineralised second primary molars can be used to predict MIH. MIH was significantly associated with childhood illness during the first three years of life, including ear infection, respiratory distress, and tonsillitis.

Association between asthma and enamel defects in primary and young permanent teeth - A systematic review

Childhood respiratory diseases, such as asthma, are important public health problems worldwide and could be associated with tooth enamel defects. This study aimed to verify the relationship between asthma and enamel defects in teeth, to answer the following question: "Could asthma in children be significantly associated with enamel defects in deciduous dentition and young permanent teeth?." PUBMED-MEDLINE, EMBASE, LILACS, and COCHRANE databases were systematically searched and assessed articles (2000-2021) were cautiously scored according to a predetermined criterion. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were considered. Twenty-two articles were critically appraised and used as a basis for conclusions. The relationship between asthma and enamel defects was confirmed in the majority of appraised papers, one with a high level of evidence, nine with a moderate level, and four with a low level. Out of the eight manuscripts investigating the influence of asthma medication on enamel defects, only three (one with high, one moderate, and another with a low level of evidence) suggested an association. It can be concluded that asthma is closely connected with enamel defects in young permanent teeth. However, as most of the papers appraised were of cross-sectional or case-control design, further well-designed clinical investigations with a prospective design are welcome to reinforce our findings.

Best clinical practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH): an updated European Academy of Paediatric Dentistry policy document

AIM

To update the existing European Academy of Paediatric Dentistry (EAPD) 2010 policy document on the 'Best Clinical Practice guidance for clinicians dealing with children presenting with Molar-Incisor-Hypomineralisation (MIH).'

METHODS

Experts, assigned the EAPD, worked on two different topics: (A) Aetiological factors involved in MIH, and (B) Treatment options for the clinical management of MIH. The group prepared two detailed systematic reviews of the existing literature relevant to the topics and following a consensus process produced the updated EAPD policy document on the 'Best Clinical Practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH).' The GRADE system was used to assess the quality of evidence regarding aetiology and treatment which was judged as HIGH, MODERATE, LOW or VERY LOW, while the GRADE criteria were used to indicate the strength of recommendation regarding treatment options as STRONG or WEAK/CONDITIONAL.

RESULTS

(A) Regarding aetiology, it is confirmed that MIH has a multifactorial aetiology with the duration, strength and timing of occurrence of the aetiological factors being responsible for the variable clinical characteristics of the defect. Perinatal hypoxia, prematurity and other hypoxia related perinatal problems, including caesarean section, appear to increase the risk of having MIH, while certain infant and childhood illnesses are also linked with MIH. In addition, genetic predisposition and the role of epigenetic influences are becoming clearer following twin studies and genome and single-nucleotide polymorphisms analyses in patients and families. Missing genetic information might be the final key to truly understand MIH aetiology. (B) Regarding treatment options, composite restorations, preformed metal crowns and laboratory indirect restorations provide high success rates for the posterior teeth in appropriate cases, while scheduled extractions provide an established alternative option in severe cases. There is great need for further clinical and laboratory studies evaluating new materials and non-invasive/micro-invasive techniques for anterior teeth, especially when aesthetic and oral health related quality of life (OHRQoL) issues are concerned.

CONCLUSIONS

MIH has been studied more extensively in the last decade. Its aetiology follows the multifactorial model, involving systemic medical and genetic factors. Further focused laboratory research and prospective clinical studies are needed to elucidate any additional factors and refine the model. Successful preventive and treatment options have been studied and established. The appropriate choice depends on the severity of the defects and the age of the patient. EAPD encourages the use of all available treatment options, whilst in severe cases, scheduled extractions should be considered.

Hypomineralized Primary Teeth in Preterm Low Birth Weight Children and Its Association with Molar Incisor Hypomineralization—A 3-Year-Prospective Study

The present prospective study was conducted to assess the prevalence of enamel hypomineralization (EH) in primary dentition among preterm low birth weight (PT-LBW) children, incidence of molar incisor hypomineralization (MIH) in the same cohorts, and to determine associations between PT-LBW, hypomineralization in primary second molars, and MIH. A total of 287 PTLBW study subjects and 290 control full-term normal birth weight subjects were followed up for 36 months. Enamel defects were recorded at baseline. The same cohorts were examined after 3 years for MIH using the European Academy of Paediatric Dentistry (EAPD) criteria. Multiple variable logistic regression models were developed. A total of 279 children (48.4%) presented with EH in primary dentition and 207 (35.9%) children presented with MIH. Children with primary second molar hypomineralization had 2.13 (R² = 0.19, 95% CI = 0.98–4.19, p = 0.005) times higher frequency of MIH. Children with PT-LBW had 3.02 times (R² = 0.31, 95% CI = 1.01–5.94, p = 0.005) higher frequency of MIH incidence after adjusting for childhood infection, prenatal history, and presence of hypomineralized primary second molars. To conclude, the present study showed significant association between PT-LBW, hypomineralized second primary molars, and incidence of MIH.

Effects of different remineralization agents on MIH defects: a randomized clinical study

OBJECTIVES

The aim of this study was to present a comparative evaluation of the long-term efficacy of fluoride varnish and pastes containing CPP-ACP and CPP-ACP with fluoride (CPP-ACFP) in the remineralization of creamy-white and yellow-brown defects in permanent first molars with MIH.

MATERIALS AND METHODS

The study included 120 teeth with yellow-brown or creamy-white defects in 67 children (37 girls, 30 boys) aged 6-9 years (mean, 7.2) who were newly diagnosed with MIH with no substance loss or caries or prior restorative treatment. The patients were randomly divided into the experiment groups; control (oral hygiene motivation only), fluoride varnish, and pastes containing CPP-ACP and CPP-ACPF, and followed up for 24 months. The evaluations were made based on the ICDAS criteria and the measurements which were performed using the laser fluorescence method (DIAGNOdent, KaVo, Biberach, Germany) in the follow-ups.

RESULTS

The research was completed with 49 patients (23 females, 26 males; mean age, 7.7) and 90 teeth. All remineralization agents increased remineralization rates in both creamy-white and yellow-brown colored defects without presenting any statistically significant difference at the end of the follow-up period (p > 0.05). However, the effects of fluoride varnishes were late to observe when compared to pastes containing CPP-ACP and CPP-ACPF.

CONCLUSIONS

Pastes containing calcium and phosphate may be recommended for the longer-term preservation of teeth with yellow-brown defects which showed a post-eruptive breakdown in a shorter time.

CLINICAL RELEVANCE

There is a lack of studies investigating MIH treatments in which lesion appearance was recorded. This study evaluated creamy-white and yellow-brown MIH defects separately and reported long-term results of different remineralization agents.

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.

Molar Incisor Hypomineralisation: Current Knowledge and Practice

BACKGROUND

Molar incisor hypomineralisation (MIH) is a common developmental dental condition that presents in childhood. Areas of poorly formed enamel affect one or more first permanent molars and can cause opacities on the anterior teeth. MIH presents a variety of challenges for the dental team as well as functional and social impacts for affected children.

OBJECTIVES

Here, we provide an up-to-date review of the epidemiology, aetiology, diagnosis and clinical management of MIH.

MATERIALS AND METHODS

A review of the contemporary basic science and clinical literature, relating to MIH, was undertaken using information obtained (up to 10 April 2020) from the electronic databases PubMed, Scopus, Web of Science and the Cochrane Library.

RESULTS

There is a growing body of evidence relating to the aetiology, presentation and clinical management of MIH. Current knowledge appears to be focused on potential genetic aspects, as well as the development and validation of indices for the diagnosis and management of MIH. There has also been increasing recognition of the global and individual burden of this common condition.

CONCLUSIONS

Dental health professionals should regularly appraise the basic science and clinical MIH literature to ensure that they provide the best possible short- and long-term care for their young patients.

Frequency of molar incisor hypomineralization and associated factors among children with special health care needs

BACKGROUND

Molar incisor hypomineralization (MIH) is a frequently encountered oral condition that varies from mild opacities to posteruptive enamel breakdown. No previous published studies have investigated the frequency of MIH and associated risk factors among children with special health care needs (CSHCN) to our awareness.

OBJECTIVES

Assess the frequency of MIH and associated risk factors among CSHCN.

DESIGN

Cross-sectional.

SETTING

Schools in provincial city of Saudi Arabia.

PATIENTS AND METHODS

The study was conducted among 400 (180 boys and 220 girls) special needs children. Diagnosis of MIH was according to the European Academy of Paediatric Dentistry criteria.

MAIN OUTCOME MEASURE

Result of logistic regression analysis that assessed the association between MIH prevalence and associated prenatal, perinatal, and postnatal factors.

SAMPLE SIZE

400 (180 boys and 220 girls) special needs children.

RESULTS

Among 400 CSHCN, 98 (24.5%) presented with MIH. Children with multiple disabilities had a 3.89 times greater risk of MIH (95% CI: 1.91-6.19, P=.002). Children with positive prenatal factors had an adjusted odds ratio (aOR) of 2.31 times for MIH (95% CI: 1.22-4.73, P=.012). Children with a childhood infection history had an aOR of 2.43 times for MIH (95% CI: 1.31-5.85, P=.014). Children with a breastfeeding history >18 months had an aOR of 3.73 for MIH (95% CI: 1.62-8.60, P=.002). Permanent maxillary first molars were the most frequently affected teeth, and demarcated opacity was the most frequent MIH type.

CONCLUSION

MIH should be recognized as one of the prevalent oral health problems among CSHCN to prevent tooth mortality.

LIMITATIONS

A cross-sectional study cannot establish a causal relationship.

CONFLICTS OF INTEREST

None.

Molar incisor hypomineralization: A review and prevalence in Japan

Molar incisor hypomineralization (MIH) is defined as hypomineralization of systemic origin of one to four first permanent molars, and incisors are also frequently affected. This disorder is a serious concern in pediatric dentistry. Teeth affected by MIH have many dental problems, such as hypersensitivity, poor aesthetics, and rapid progression of dental caries. The prevalence of MIH ranges from 2.8% to 21% among studies with more than 1000 subjects in different countries and age groups. The etiology of MIH is unclear, but genetic and environmental factors have been proposed. This review describes the prevalence, etiology, and clinical management of MIH. A detailed description of MIH prevalence in Japan is also provided.

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.

Molar Incisor Hypomineralization in Children with Intellectual Disabilities

The aim of the study is to compare the frequency and the distribution of molar incisor hypomineralization (MIH) in children with intellectual disabilities.

METHODS

Seventy-two children with intellectual disabilities and 72 healthy children were included in the study. They ranged in age from 5 to 18 years with the same distribution by age and sex. Standard clinical examination was performed, at a dental clinic or in the institution where the children lived, by using a dental mirror and a probe, according the European Academy of Paediatric Dentistry judgment criteria for MIH.

RESULTS

Among the 72 children with intellectual disabilities, eight children (11.1%) presented MIH with 19 affected teeth. In the control group, one child (1.4%) presented MIH with two affected teeth. The difference was statistically significant (p = 0.033). There were no statistically significant differences between boys and girls. The molars, especially the first right molars were the most affected tooth. Brown defects were less common than white defects.

CONCLUSION

Children with MIH should be identified because this condition is a common problem in children with intellectual disabilities.

Molar Incisor Hypomineralization (MIH) in a Child with Congenital Chronic Intestinal Pseudoobstruction (CIPO)

Molar incisor hypomineralization (MIH) is a qualitative enamel defect of systemic origin affecting 1-4 permanent first molars (PFMs) frequently in association with affected permanent incisors (PIs). The exact etiology of MIH is still unclear but considered to be multifactorial. This present case report to the best of our knowledge is the first case reported which acknowledges MIH in a patient with chronic intestinal pseudoobstruction (CIPO) with underlying neurological disease due to somatic mitochondrial disorder. It also elicits the availability of various contemporary treatment options and their proper selection and early intervention to manage the functional and aesthetic problems caused by enamel defects and to improve the quality of life in the patients.

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.

Molar incisor hypomineralisation in Lebanon: prevalence and clinical characteristics

BACKGROUND

Molar incisor hypomineralisation (MIH) is a qualitative enamel developmental defect affecting 1-4 first permanent molars and sometimes the permanent incisors. MIH is extremely widespread around the world and presents a considerable clinical problem in paediatric dentistry. Although, little prevalence data exist for Middle East populations including the Lebanese one.

AIM

The objectives of this study were to investigate the prevalence of MIH in 7-9-year-old Lebanese children, with relevance to gender, jaw and side distribution, and to assess the clinical status, extent and severity of MIH lesions of the affected teeth.

DESIGN

Representative sample (n = 659) of 7-9-year-old Lebanese children attending private and public schools distributed throughout Lebanon was examined for MIH. Clinical status, extent and severity of MIH lesions on FPMs and permanent incisors were scored using the short-form grading method (MIH index) of Ghanim et al. (Eur Arch Paediatr Dent 16:235-246, 2015).

RESULTS

An overall MIH prevalence of 26.7% was reported with no significant predilection for girls over boys. 52.8% of the cases present with only molars and. 47.2% with both molars and incisors and did not present any significant difference between upper and lower jaws (P = 0.325). Left-side FPMs were more affected than the right ones (P = 0.0218). Central incisors were significantly more affected than the laterals in both jaws (P < 0.0001). Maxillary central incisors were significantly more affected than their mandibular counterparts (P < 0.0001). Most of the clinical status was demarcated opacities extended on less than the third of the tooth surface. The extent of lesions correlated significantly with the number of affected molars. Most of the affected teeth presented with mild defects and the degree of severity was not correlated with gender but significantly increased with age.

CONCLUSIONS

MIH is prevalent in Lebanon. Further studies are required to analyse the possible systemic and environmental etiologies among Lebanese children.

Prevalence, aetiology, and treatment of molar incisor hypomineralization in children living in Izmir City (Turkey)

BACKGROUND

Molar incisor hypomineralization (MIH) is frequent in children and etiology is different.

AIM

The aim of this study was to determine the prevalence, severity, and risk factors of MIH and to investigate the relationship between the severity of the defect in the teeth affected by MIH and the risk factors.

DESIGN

The study included patients at the age range of 9 and 10 years, who were admitted to the clinic of paediatric dentistry in Dokuz Eylul University and had four-first molar teeth (FMT) and eight incisor teeth eruptions in the jaws. The presence of only demarcated opacities in one or several FMT and incisor teeth was defined as MIH1, and the presence of post-eruptive breakdown (PEB), atypical restorations, and extracted teeth was defined as MIH2.

RESULTS

MIH was detected in 142 (11.5%) of 1237 children. Although there was no statistically significant difference between upper and lower FPM and the occurrence of MIH (P < 0.902), there was a difference between upper and lower central and lateral teeth (P < 0.001; P < 0.009). A significant difference was detected between birth week, birthweight, high fever, and asthma/bronchitis and MIH1 and MIH2 (P < 0.001).

CONCLUSION

The prevalence of MIH was found to be 11.5%. It was observed that the patients undergoing low birthweight, preterm delivery, high fever, and asthma/bronchitis were more severely affected by MIH.