Peripartum events and molar-incisor hypomineralisation (MIH) amongst young patients in southwest France

Insights into molar-incisor hypomineralisation in past populations: A call to anthropologists

OBJECTIVE

Molar incisor hypomineralisation (MIH) is a developmental defect of enamel affecting the first permanent molars and often the incisors and affecting approximately 13% of the current population worldwide. Here, we aim to highlight potential differential diagnoses of MIH in archaeological collections (taphonomic discoloration, amelogenesis imperfecta, fluorosis, rachitic teeth, etc.).

METHODS

Causative factors of dental discolourations are identified through a literature review.

RESULTS

In an archaeological context, the sediments contained in the burial soil can lead to tooth discoloration. Taphonomic staining of the dentition may have a similar appearance to enamel hypomineralisation, and thus is a confounding factor that has the potential to cause miscalculation of the true prevalence of MIH within archaeological collections. Some rare medieval cases are reported in the modern literature but without microanalysis, misdiagnosis is possible. The aetiological factors of MIH are unknown but probably follow the multifactorial model involving systemic medical and genetic factors.

CONCLUSIONS

Systematic detection and diagnosis of MIH during anthropological studies is therefore of great interest.

SIGNIFICANCE

The hypotheses that only contemporary agents are causative factors of MIH could be refuted by the discovery of individuals living before medication or pollutants. The identification of MIH in a group of individuals also provides information regarding the health status of a population and reflects stress occurring during the period of mineralisation of the first permanent molars after secretion of the enamel matrix.

LIMITATIONS

Taphonomic alterations of archaeological remains prevent MIH diagnosis.

SUGGESTIONS FOR FUTURE RESEARCH

MIH diagnosis can be difficult in archaeological series and further non-destructive methods (microtomography, elemental analyses, etc.) are required.

MIH and Dental Caries in Children: A Systematic Review and Meta-Analysis

(1) Background: Molar-incisor hypomineralization (MIH) is a clinical condition affecting permanent teeth in children, with a documented rising trend in the last two decades. The aim of the present study was to analyze and synthesize the available evidence on caries experience (dmft/DMFT) and MIH in children. (2) Methods: A systematic review and meta-analysis were conducted according to the PRISMA statement. (3) Results: 59 papers published between 2007 and 2022 were included in the qualitative synthesis and 18 in the meta-analysis. The total sample of subjects was 17,717 (mean: 896), of which 2378 (13.4%) had MIH (mean: 119), with a girl/boy ratio of 1:1. The mean age of the enrolled participants was 8.6 (age range 7-10 years). Meta-analysis showed that MIH has a positive correlation with both dmft (effect size of 0.67, 95% CI [0.15, 1.19]) and DMFT (effect size of 0.56, 95% CI [0.41, 0.72]); (4) Conclusions: Children with MIH should be diagnosed correctly and on time. Treatment and management options for moderate and severe forms of MIH should consider prognosis based on known risk factors, and secondary and tertiary prevention policies should also consider the multifactorial nature of caries etiology.

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.

Molar Incisor Hypomineralization in adolescents and adults and its association with facial profile and occlusion

OBJECTIVES

To date, there are no data available in the scientific literature about the diagnosis of Molar Incisor Hypomineralization (MIH) in adults. We aimed to assess the MIH prevalence and clinical characteristics in adolescents and adults and its association with facial profile and occlusion.

MATERIALS AND METHODS

In this cross-sectional study, permanent teeth were evaluated in 275 patients between the ages of 12 and 49 at a dental clinic, using intraoral photographs. A calibrated examiner classified enamel hypomineralization using the MIH index. Statistical analyses were performed using chi-square, Fisher's tests, and ordinal logistic regression.

RESULTS

MIH was observed in 12.73% of all patients. The most commonly affected teeth were permanent molars, while incisors, premolars, and canines were less affected. MIH usually appears as demarcated opacities, with less than one-third of the tooth affected. There was no association between severe defects and facial profile and occlusion, but rather with the higher age of the participants.

CONCLUSION

Enamel hypomineralization mainly affects the first and second permanent molars, but it could also be observed in the third molars, although it is not associated with the orthodontic characteristics investigated.

CLINICAL RELEVANCE

This is the first study to highlight the prevalence of MIH in adults. This result showed the importance of other specialists beyond Pediatric Dentistry in the diagnosis of this defect. In addition, hypomineralization of other permanent teeth (canines, premolars, and second molars) has been described previously in other studies, but this is the first to identify MIH in third molars.

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.

Perinatal hypoxia and the risk of severe Molar-Incisor Hypomineralisation (MIH): a retrospective analysis of the pH value of umbilical arterial blood after birth

PURPOSE

Molar-Incisor Hypomineralisation (MIH) remains a widespread developmental disorder of the teeth with a still largely unknown etiology. Perinatal events were blamed in previous studies for the development of MIH. The aim of the present study was to evaluate the influence of perinatal hypoxia-determined by the pH value of the umbilical cord blood-and to investigate its correlation with severe MIH retrospectively. In addition, cesarean section was recorded as differentiation variable.

METHODS

A total number of 138 children (mean age 8.0 years ± 1.7), who were treated for severe MIH in a dental office in Berlin between the years 2008 and 2019, were included in the study. The control group was comprised of patients with the same date of birth (44 children, mean age 7.7 years ± 1.7). Information on the pH value of the arterial blood from the umbilical cord taken immediately after birth, whose recording is mandatory in Germany, was received from the parents by letter survey requesting the entries from the German Child Health Booklet.

RESULTS

In the group of the male children born without cesarean section, the pH value of the control group was significantly lower (7.19 ± 0.09) than the pH value of the MIH group (7.27 ± 0.07, p = 0.0008). In female children born with or without cesarean section as well as in male children born by cesarean section there were no significant differences between the MIH and control group.

CONCLUSIONS

No significant association between MIH and the pH value of the umbilical cord blood or birth by cesarean section could be found in the examined patient population.

Prenatal, perinatal and postnatal events associated with hypomineralized second primary molar: a systematic review with meta-analysis

OBJECTIVE

The etiology of hypomineralized second primary molar (HSPM) appears to be multifactorial but remains uncertain. Thus, the objective was to systematically review studies that investigated adverse health conditions in the prenatal, perinatal and postnatal periods associated with HSPM.

MATERIAL AND METHODS

The search was carried out in five databases and in gray literature. The risk of bias of observational studies was analyzed according to the Newcastle-Ottawa scale.

RESULTS

A total of 1878 studies were identified. Fourteen were eligible, and seven were included in the meta-analysis. Maternal smoking (OR = 2.88; 95%CI: 1.62-5.15) and presence of maternal hypertension (OR = 2.91; 95%CI: 1.35-6.28) were significantly associated with higher odds of HSPM. In the perinatal period, factors associated with HSPM were low birth weight (OR = 1.50; 95%CI: 1.15-1.96), prematurity (OR = 1.93; 95%CI: 1.37-2.71), delivery complications (OR = 2.42; 95%CI: 1.52-3.83) and need for an incubator (OR = 1.65; 95%CI: 1.01-2.70). Not breastfeeding (OR = 1.26; 95%CI: 1.01-1.58), use of antibiotics by the child (OR = 1.24; 95%CI: 1.04-1.48), fever (OR = 1.37; 95%CI: 1.10-1.72) and asthma (OR = 1.91; 95%CI: 1.16-3.13) were the postnatal factors associated with HSPM.

CONCLUSION

Maternal smoking, maternal hypertension, low birth weight, prematurity, delivery complications, need for incubation, not breastfeeding, antibiotic use, fever and childhood asthma were associated with HSPM. Well-designed prospective cohort studies are needed. Clinical relevance Understanding the etiological factors can be guiding aspects for individual clinical approaches, as well as guiding the design of preventive interventions for HSPM.

Etiology of Molar-Incisor Hypomineralization (MIH): A Cross-Sectional Study of Saudi Children

(1) Background: Molar-incisor hypomineralization (MIH) is a common clinical condition with critical negative consequences for dental health. The etiology of MIH is still not completely understood, although several theories have been suggested. (2) Aim: To investigate the etiology of MIH defects in a sample of Saudi school children. (3) Method: A total of 893 school children in the age range of 8–10 years participated in the study. The sample was taken from Riyadh City, Saudi Arabia. The participating children were examined for MIH using the European Academy of Pediatric Dentistry Criteria. The children’s parents were asked about the child’s pre, peri-, and postnatal condition utilizing a structured and validated questionnaire. (4) Results: A total of 362 children (168 males and 194 females) were affected with MIH, for a prevalence of 40.5%. Among all analyzed etiological factors, only jaundice was found to be significantly associated with MIH in children (OR = 1.35, p = 0.047). Multivariate logistic regression analysis confirmed that the only significant etiological factor for MIH was newborn jaundice (p = 0.04). (5) Conclusion: Newborn jaundice was the only etiological factor that showed a significant association with MIH in the studied Saudi school children.

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.

Relationship between preterm birth and developmental defects of enamel: A systematic review and meta-analysis

BACKGROUND

A putative relationship between preterm birth and developmental defects of enamel (DDE) has been described in the literature. Although systematic reviews have found preterm birth may lead to DDE, the effect size has not been quantified.

AIM

The aim of this systematic review and meta-analysis was to determine the association between preterm birth and DDE.

DESIGN

An electronic search was performed in PubMed, Cochrane Library, Scopus, and Web of Science to identify relevant studies. Two independent reviewers selected the studies in a two-stage process in accordance with the PRISMA statement. The risk of bias was also analysed using the Newcastle-Ottawa Scale criteria.

RESULTS

A total of 1041 publications were considered after an electronic search, 20 of which were included in the systematic review. Of these 20 publications, 18 articles were included in a meta-analysis. The meta-analysis detected an increased risk of developing DDE in preterm children [OR: 3.27 (95% CI 2.02, 5.30; P < .001)], with a greater risk in the primary dentition. In addition to this, a subgroup analysis showed a greater risk in the development of hypoplasia in preterm children.

CONCLUSIONS

The results of this meta-analysis showed a three times increased risk of developing DDE in preterm children.

The possible influence of genetic aetiological factors on molar-incisor hypomineralisation

OBJECTIVE

The present study searched for evidence of possible associations between some genetic factors that could affect the development of molar-incisor hypomineralisation (MIH).

METHODS

In 113 patients who were surgically treated at an Otorhinolaryngology and Cervicofacial Surgery Clinic (ORL) during early childhood, human leukocyte antigen (HLA) DQ2 and DQ8 haplotypes and single nucleotide polymorphisms (SNP) of eight amelogenesis-related genes were searched in genomic DNA. Genotypes were determined by high resolution melting (HRM), TaqMan genotyping assays, and Sanger sequencing. Association between MIH and the HLA DQ2 and DQ8 alleles was tested using a univariate logistic regression. The significance of genetic variants was analysed using the Cochran-Armitage tests for trend and the Fisher exact tests.

RESULTS

We identified MIH in 22 (19.5 %) of the 113 children. Among the evaluated genetic variants, SNP rs2245803 in the MMP20 gene in a homozygous form in a recessive model was associated with MIH development (OR, 2.796; 95 %CI, 1.075 - 4.783; p = 0.0496) with the genotype distribution of TT(3), TG(6) or GG(13) in children with MIH and distribution of TT(18), TG(42) or GG(31) in children without MIH.

CONCLUSIONS

While the aetiology of MIH remains unclear, our findings suggest that variants of genes associated with amelogenesis may play important roles in susceptibility to MIH.

A systematic review and meta-analysis of systemic exposure associated with molar incisor hypomineralization

OBJECTIVE

To evaluate systemic exposures associated with molar incisor hypomineralization (MIH).

METHODS

This systematic review was performed using published observational studies that evaluated the systemic exposures associated with MIH. The sources of articles searched were PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and Grey literature. The risk of bias was analysed according to the Newcastle-Ottawa Scale for quality assessment. The meta-analysis was performed considering the exposures during the prenatal, perinatal and postnatal periods using the CMA software.

RESULTS

A total of 4207 articles were identified. Twenty-nine studies were eligible for inclusion and 27 were included in the meta-analysis. The studies presented low and moderate risks of bias, except for one that was classified as having a high risk of bias. Maternal illness during pregnancy (OR 1.40; 95% CI 1.18-1.65, P < 0.0001) and psychological stress (OR = 2.65; 95% CI 1.52-4.63; P = 0.001) was observed to be significantly associated with higher odds of MIH. During the perinatal period, caesarean delivery (OR = 1.32, 95% CI 1.11-1.57, P = 0.001) and delivery complications (OR = 2.06; 95% CI 1.47-2.88, P < 0.0001) were also associated with MIH. In the postnatal period, only respiratory diseases (OR = 1.98; 95% CI 1.45-2.70, P < 0.0001) and fever (OR = 1.50; 95% CI 1.22-1.84; P < 0.0001) were associated with higher prevalence of MIH. The evidence was graded as very low quality.

CONCLUSIONS

Maternal illness, psychological stress, caesarean delivery, delivery complications, respiratory diseases and fever during the first years of a child's life were significantly associated with a higher odds of MIH. However, this should be interpreted with caution, once the primary studies were observational, with serious limitations according to the risk of bias, imprecision, and inconsistency. Further, well-designed cohort studies are still required.

Molar-Incisor Hypomineralization: Positive Correlation with Atopic Dermatitis and Food Allergies

AIM

Molar-incisor hypomineralization is a disturbance in dental development that involves first permanent molars as well as permanent incisors with a prevalence that ranges from 2.5% to 40%. The objective of this study was to investigate the etiology of molar-incisor hypomineralization among school children from two randomly selected towns in the province of Barcelona, Spain.

STUDY DESIGN

A cross-sectional study was conducted with 705 children ranging in age from six years-old to 14 years and 11 months-old. Full mouth examinations were carried out in accordance with the European Academy of Paediatric Dentistry criteria for the diagnosis of molar-incisor hypomineralization, from April to July 2016.

RESULTS

A total of 56 cases of molar-incisor hypomineralization were found in 22 (39.3%) boys and 34 (60.7%) girls. MIH was significantly more prevalent among those who had atopic dermatitis (OR=90.9; 33.4-247.1 CI 95%), food allergies (OR=104.2; 12.2-887.5 CI 95%), bronchitis/asthma (OR=5.3; 2.7-10.1 CI 95%), varicella (OR=96.3; 41.9-221.1 CI 95%), otitis media (OR=12.2; 6.3-23.5 CI 95%), pneumonia (OR=276.7; 35.1-2183.7 CI 95%), and febrile syndrome (OR=7.8; 4.1-14.8 CI 95%).

CONCLUSIONS

The present research reveals for the first time a statistically significant relationship between atopic dermatitis and food allergies with the presence of molar-incisor hypomineralization.

Analytical evidence of enamel hypomineralisation on permanent and primary molars amongst past populations

Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) involve prevalent qualitative structural developmental anomalies of tooth enamel affecting the first permanent molars (and often incisors) and the second primary molars, respectively. These demarcated hypomineralised lesions of enamel manifest as white-cream or yellow-brown opacities, with possible post-eruptive localised loss of enamel. Aetiological hypotheses have involved contemporary life factors (i.e. environmental pollutant exposure or early childhood medications) in contrast to factors not limited to a specific time period (i.e. hypoxia at birth or genetic predisposition). Evidence of MIH in ancient populations would reinforce aetiological factors present for many centuries. By means of microtomographic and X-ray fluorescence analyses the present study provides evidence that (i) two archaeological specimens: “S407” (Sains-en-Gohelle, France, 12^th–16^th centuries) and “B335” (Beauvais, France, 15^th–18^th centuries) were MIH-affected, and (ii) one individual “S323” was affected by HSPM and MIH (Sains-en-Gohelle, France, 7^th–11^th centuries).