Molar Incisor Hypomineralization Research Articles

Early extraction of first permanent molars: applying the evidence

First permanent molars (FPM) are often of poor prognosis due to caries or molar incisor hypomineralization. If extraction can be planned then FPM may be extracted at a suitable time to allow spontaneous space closure from the second molar, or retained for the space to be used for orthodontics in the future. There are several evidence based patient and dental factors to consider in planning these cases. This paper illustrates these factors through a case series. CPD/Clinical Relevance: Ideally, poor prognosis 6s would be managed by a paediatric dentist and an orthodontist. However, where these services are not available, the general dentist should be aware of factors influencing treatment.

Is Aberrant DNA Methylation a Key Factor in Molar Incisor Hypomineralization?

Molar incisor hypomineralization (MIH) is a qualitative disturbance of the enamel of the permanent molars and/or incisors. Its etiology is not clearly defined but is connected with different factors occurring before and after birth. It remains difficult to identify a single factor or group of factors, and the problem is further complicated by various overlapping mechanisms. In this study, we attempted to determine whether DNA methylation—an epigenetic mechanism—plays a key role in the etiology of MIH. We collected the epithelium of the oral mucosa from children with MIH and healthy individuals and analyzed its global DNA methylation level in each child using a 5-mC DNA ELISA kit after DNA isolation. There was no statistically significant difference between the global DNA methylation levels in the study and control groups. Then, we also analyzed the associations of the DNA methylation levels with different prenatal, perinatal, and postnatal factors, using appropriate statistical methods. Factors such as number of pregnancies, number of births, type of delivery, varicella infection (under 3 years old), and high fever (under 3 years old) were significantly important. This work can be seen as the first step towards further studies of the epigenetic background of the MIH etiology.

Outcome of vital pulp therapy in deeply carious molars affected with molar incisor hypomineralisation (MIH) defects: a randomized clinical trial.

To evaluate clinical and radiographic outcomes of vital pulp therapy (VPT) in deeply carious young permanent first molars (PFM) affected with MIH over 24months. In this prospective randomized clinical trial, n = 50 children with deeply carious young PFM affected with MIH, and diagnosed with reversible or irreversible pulpitis were randomized into 2 groups: indirect pulp treatment (IPT) and pulpotomy (partial or complete). Teeth were followed up clinically and radiographically for 24months. Statistical analysis was done using Chi-square test; P ≤ 0.05 was considered significant. A total of n = 50 teeth/patients (n = 26 females (52%), n = 24 males (48%))wereincluded, and 14 upper and 36 lower PFM were treated. Mean age was 11 ± 3.2years. Clinical and radiographic success rates were: 96% for IPT, 90% for PP and 82% for CP (and 86% for both types of pulpotomy combined) over 24months. There were no significant differences in outcomes between treatment groups. Age, gender and tooth location/jaw were found to have no statistically significant difference in outcomes among treatment groups, nor did pulpal status or root maturity, regardless of type of VPT and follow up period. VPT is a valid treatment option in deeply carious young permanent first molars affected with MIH over 24months. IPT had a higher clinical and radiographic success rate (96%) than partial or cervical pulpotomy (total 86%), but the difference was not statistically significant. Future randomized clinical trials on VPT for teeth affected with MIH are recommended with larger sample size and longer follow-up.

Knowledge, perception, and clinical experiences on molar incisor hypomineralization amongst Portuguese dentists

AimMolar incisor hypomineralization (MIH) is a prevalent oral health condition whose knowledge by dentists is key to the best clinical outcome. This study aimed to evaluate the knowledge, perceptions and clinical experiences of MIH among Portuguese dentists.MethodsA cross-sectional structured questionnaire was distributed nationally through a web-based survey platform. Data concerning demographic variables, years of experience, dental specialty, MIH prevalence, diagnosis, severity, training demands and clinical management of MIH were collected. We calculated a knowledge score (KS), and compared data between Pediatric Dentists (PDs), General Dental Practitioners (GDPs) and other dental specialties (ODS).ResultsOverall, 2.2% of Portuguese dentists (n = 257) answered the questionnaire. Most participants reported having identified MIH in their practice (82.5%), with PD reporting the prevalence appeared to have increased, and practically all (91.7%) considered it a public health problem. Resin composite was often the used material to restore MIH teeth (56.0%), however PDs indicated glass ionomer cements as the preferred and preformed crowns a better option. The average KS on MIH was 41.3 (± 5.7), with GDPs having a similar score than PDs. Most respondents (94.9%) reported a lack of information about MIH and were willing to receive appropriate clinical training.ConclusionsThe average knowledge on MIH was considered low among Portuguese dentists. Respondents perceived an increased incidence of MIH, despite the lack of prevalence data in Portugal. The material of choice was Glass Ionomer and performed crowns, by PDs, while GDPs and ODS reported poor confidence to manage MIH. These results may serve future programs to increase knowledge, perceptions and clinical experiences towards MIH.

Patient-reported outcome measures for children and adolescents having dental bleaching in the UK

PurposeDental bleaching in paediatric patients can be used to address discolouration of teeth due to trauma, endodontic treatment, or enamel and dentine defects. Despite being a minimally invasive and successful treatment, the use of bleaching products in children and young people remains controversial. This evaluation was designed to provide insight into the child’s perspective on dental bleaching and the influence that this treatment has upon their life.MethodA dental bleaching patient reported outcome measure (PROM) was developed and piloted in 2019. Data were collected from 3 UK units (January–March 2020). Children attending these units for bleaching reviews were invited to complete the PROM.ResultsTwenty seven PROM questionnaires were completed including 19 courses of external bleaching and 8 courses of internal/external bleaching. The average age was 14 years old (9–17 years). The common indications for bleaching were Amelogenesis Imperfecta, dental trauma and Molar Incisor Hypomineralisation. Patients reported improvements in their appearance (89%) and self-confidence (81%). Sensitivity was the most common side effect, reported in 63% of cases.ConclusionThis PROM supports the use of dental bleaching in children and young people when treating dental disease that causes discolouration. Bleaching not only improved the appearance of teeth, but also patients’ self-confidence. Sensitivity is a common side effect and clinicians should discuss this common risk and its management with patients and their families.

Prevalence of Molar-incisor hypomineralization in Iranian children – A systematic review and narrative synthesis

IntroductionMolar-incisor hypomineralization is a developmental defect of enamel with clinical features vary from demarcated opacities to severe tissue breakdown which calls for considerable preventive and interceptive measures. The aim of this article was to systematically review the literature on the prevalence of MIH in Iran and highlight the condition in Iranian children.Materials and MethodsA systematic search of literature was conducted in Scopus, Pubmed, Ovid, Embase, Web of Science, and Google-Scholar as well as national Iranian database and digital archives of dental schools from the beginning of 2000 to the end of 2021 for published and unpublished studies. Data from cross-sectional, cohort, and case-control studies on prevalence of molar-incisor hypomineralization among 6–13-year-old children was gathered, using the following MeSH terms and keywords and their Persian equivalents: Prevalence, Hypomineralisation, Hypomineralization, MIH, “molar incisor”, “molar-incisor”, “cheese molars”, “Hypomineralised first permanent molars”, “Hypomineralized first permanent molars”, “developmental defects of enamel”, “enamel developmental defects”, Iran*. Methodological quality and the risk of bias of quantitative studies was assessed using a modified version of Newcastle-Ottawa Scale. Due to the considerable clinical and statistical heterogeneity of the included studies, pooling of data through meta-analysis was not possible. Therefore, a descriptive synthesis of data was performed.ResultsFifteen cross-sectional studies with a total number of 12011 participants were included in the systematic review. The prevalence of MIH ranged from 5.1% to 25.6%. All of the included studies were at a moderate risk of bias (NOS of 4-6). The lowest prevalence of MIH was reported in Kerman (5.14%) and the highest in Tehran (25.6%). Substantial methodological, clinical and statistical heterogeneity was observed.ConclusionThis is the first study to systematically review the available literature on MIH prevalence in Iran. However, the present review has some limitations such as limited number of included studies, large heterogeneity of the research, and moderate quality of included studies. Further high-quality research is warranted.

Top tips for paediatric dentistry - Part 3: operative care, stainless steel crowns and management of molar incisor hypomineralisation

Top tips for paediatric dentistry - Part 3: operative care, stainless steel crowns and management of molar incisor hypomineralisation

Changes in oral health-related quality of life after treatment of molar incisor hypomineralisation using Glass Hybrid Restorations.

To assess the changes in children's oral health-related quality of life following the treatment of severely affected molar-incisor hypomineralisation with Glass Hybrid Restorative System (GH) after selective caries removal. The observational cross-sectional study was conducted at the Marmara University, School of Dentistry, Department of Pediatric Dentistry, Istanbul, Turkey.. Children aged 11-14 years (n = 55) who were diagnosed with MIH and had finished their dental treatment from November 2018 to December 2019, were included. The children's MIH-affected teeth were treated with GH after SCR. Participants answered the Child Perceptions Questionnaire (CPQ11?14) prior to their dental treatment and 6 months after the treatment. Of the fifty-five patients, 40 patients (24 girls-16 boys) completed baseline and follow-up data. The mean age of the children was 11.85 ±1.02 years. The overall CPQ score ranged from 3-83 (average 33.27 ± 16.46) at baseline and 0-61 (average 11.67 ± 11.21) at follow up. The emotional well-being among children was the highest score at baseline. A significant decrease (p < 0.001) in the mean values was observed for both the overall CPQ scores and for the scores of the oral symptoms, functional limitations, and social-emotional well-being limitation. All subdomains showed large effect sizes and oral symptom limitation domain presented the greatest effect. Wilcoxon Rank test was used to determine the statistical significance of the changes and the magnitude of change was determined by calculating and classifying the effect size. Restorative treatment with GH following selective caries removal positively influenced the oral health-related quality of life of children with severe molar-incisor hypomineralisation.

Management of molar–incisor hypomineralization and hypodontia in monozygotic twins: a case report

Molar–incisor hypomineralization (MIH) is the hypomineralization of permanent first molars and is often associated with similarly affected incisors. This can lead to caries development and post-eruptive enamel breakdown. Early diagnosis and management are of prime importance to prevent premature loss of these molars at a young age, and to mitigate against negative changes on the patient's quality of life. This is particularly true when the patients also present with hypodontia. Wherever possible, conservative management in primary care should be undertaken. This case report explores the presentation and on-going treatment of MIH, and hypodontia, illustrated in monozygotic twin males. CPD/Clinical Relevance: It is important to consider factors involved in the early identification of MIH and hypodontia and to develop strategies to treat the patient.

Assessment of Knowledge, Attitude and Practice of Molar-Incisor Assessment of Knowledge, Attitude and Practice of Molar-Incisor Hypomineralisation among a Group of Egyptian Dentists Hypomineralisation among a Group of Egyptian Dentists (Observational Cross-Sectional Study) (Observational Cross-Sectional Study)

Introduction: Molar Incisor Hypomineralisation (MIH) is one of qualitative DED. MIH is increasing dramatically in the new generations, which is considered to be challenging for the majority of dentists. MIH was found to be prevalent in 14.2% of the world's population, with the high incidence 18% in South America and the least (10.9%) in Africa. This study was carried out to assess the knowledge, attitude, and practice of graduated Egyptian dentists' group regarding MIH condition and compare the outcome information among different dental specialists. Material and methods: A google based questionnaire based on previously validated published papers distributed electronically through different social media by direct message or public social media link. Eligibility criteria including Graduated Egyptian licensed dentists excluding students, interns and other medical specialties. Model answer prepared by researchers in 3 rounds based on most recent published papers. Results: 416 participants enrolled in this study with response rate reach to 16.7% for direct message and 1.4% for public share link. 79.1% of PDs, 45.8% of GPs and 45.0% of other specialties are familiar with both MIH condition and terminology. A prevalence of 10-20 % was notice by participants during their practice (21.9% PDs, 22.0% GPs and 22.2 other specialties). Most of participants believe that there is a lack of information regarding MIH between Egyptian dentists. The majority of the participant used Full coverage for posterior teeth and composite resin for anterior teeth as treatment choice. 53.1% of PDs are encountered MIH in monthly bases. Conclusion: MIH is a clinical problem that Egyptian dentists well recognize and frequently encounter in clinical practice. There is a need to include MIH in academic curriculum to increase the awareness regarding the condition and clinical management.

Predisposing factors involved in the aetiology of Molar Incisor Hypomineralization: a case-control study.

The aetiology of Molar Incisor Hypomineralisation (MIH) is currently unclear. Over time, several aetiological hypotheses have come forward, including pre- and perinatal medical problems and postnatal illness. The aim of this case-control study is the identification of possible predisposing factors involved in MIH aetiology. Methods Study Design: By hypothesising the probability of at least one predisposing factor present 2.5 times more in MIH cases than in controls, with an estimated prevalence of MIH patients requiring therapy equal to 30%, at a unilateral alpha level of 5% and a power of 80%, 63 couples of subjects are needed with an allocation ratio of 1:1; individual matching for age and gender was carried out. After clinical examination, 78 children with MIH (EAPD criteria) were recruited (mean age 9.36 years). An anamnestic form filled-in by a parent was used to collect data on possible predisposing factors including demographic characteristics, pregnancy, birth, childhood medical illness and medications' intake. One-tail McNemar chi square test was used to evaluate the significance of the association between predisposing factor and MIH; odds ratio and 95% confidence intervals were computed. A multifactorial aetiology may be advocated for MIH development; in particular, further investigations are required to confirm and clarify the role of genetic factors.

Comprehensive Management of Molar-Incisor-Hypomineralization by Preventive, Palliative, and Restorative Treatment Modalities in a Pediatric Patient: A Case Report and Literature Review

Molar–incisor–hypomineralization (MIH) is a developmental defect of enamel dental tissue caused by the disturbances in the maturation stage of amelogenesis. It usually affects the permanent first molars and incisors. In children, MIH condition clinically appears as the demarcated discolored hypomineralized defects of affected teeth, post-eruptive breakdown (PEB) of affected enamel, dentine exposure, hypersensitivity, increased susceptibility to dental caries and behavioral management challenges owing to dental anxiety/fear and dental esthetic concerns. This case report describes the comprehensive dental management of MIH in an 8-year-old male pediatric patient by conservative and noninvasive treatment approach with preventive, palliative, and restorative treatment modalities under nonpharmacological behavior management techniques.

Auswertungen zur Hypersensitivität und zu unterschiedlichen Versorgungsansätzen an MIH-Zähnen

Purpose: In view of the still high prevalence of molar incisor hypomineralization (MIH), the restoration of teeth with hypersensitivity and enamel and dentin breakdown remains relevant in everyday practice. The aim of this study was to investigate the extent of clinical hypersensitivities in MIH teeth and to compare different restorative strategies based on their survival data.Methods: Children between the ages of 6 and 18 years who had at least one MIH tooth requiring treatment were included and the severity of hypersensitivity was documented using the Schiff Cold Air Sensitivity Test. In addition, a qualitative assessment of all MIH-related restorations and analysis of their survival data were conducted.Results: A total of 350 MIH teeth were included in the study. Minor to moderate hypersensitivities were predominantly found on teeth with opacities and atypical restorations. Significantly increased hypersensitivities were detected on teeth with hard tissue defects, on molars, and in young patients (6-7 years). Survival data of the 204 MIH-related restorations assessed revealed a 3-year cumulative survival probability of 100.0 % for CAD/CAM-manufactured ceramic crowns, 76.2 % for conventional composite restorations, 29.9 % for noninvasive composite restorations, and 7.0 % for noninvasive glass ionomer cement restorations.Conclusions: The study results showed that hypersensitivity on MIH teeth is a clinical problem and severity varies. Furthermore, diverging survival rates were documented for different types of treatment on MIH teeth. While simplified procedures showed reduced survival probabilities, conventionally placed composite restorations and indirect CAD/CAM-manufactured restorations on MIH teeth showed high survival probabilities.

Prevalence, Caries, Dental Anxiety and Quality of Life in Children with MIH in Brussels, Belgium.

Molar incisor hypomineralisation (MIH) is a dental enamel pathology responsible for unfavorable functional and aesthetic implications. The objective of this study is to assess the prevalence, dental anxiety, and quality of life related to oral health in children with MIH. In 14 schools in Brussels, Belgium, 290 children aged 8 to 9.5 answered Children’s Fear Survey Schedule-Dental Subscale (CFSS-DS) and Child-Oral Impact on Daily Performance (C-OIDP) questionnaires to assess dental anxiety and quality of life related to oral health (OHRQoL). Oral examinations allowed us to detect MIH according to standardized criteria. The MIH prevalence was 18.6%. The Decayed, Missing and Filled Teeth index (DMFT index) of MIH patients was significantly higher than non-MIH patients (p < 0.001), mainly due to more restored teeth. There was no significant association between MIH and dental anxiety or OHRQoL. Caries in the deciduous dentition was significantly associated with impaired quality of life. The MIH prevalence in Brussels is comparable to other European countries. MIH had no significant impact on dental anxiety and OHRQoL in this sample. The dynamic nature of MIH lesions requires early diagnosis and management to limit the evolution of the severity of the lesions and their implications. It is possible that older age groups may present more symptoms, however, this would require a longitudinal study.

Esthetic and functional rehabilitation of hypomineralized first permanent molars using prefabricated versus custom made zirconia crowns: a 12-month follow-up study

Background: Molar incisor hypomineralisation is defined as “hypomineralisation of systemic origin, presenting as demarcated, qualitative defects of the enamel of one to four first permanent molars frequently associated with affected incisors. MIH is also considered as a public health issue since it leads to pain, poor esthetics and has a negative impact on the quality of life. Thus, managing patients with MIH requires a variety of patient management approaches, materials, and techniques ranging from Intracoronal to extracoronal full or partial coverage restorations. To evaluate the efficacy of prefabricated zirconia crowns and custom-made zirconia crowns used on hypomineralised molars and to compare their efficacy in terms of gingival health, surface integrity, retention, parental satisfaction, time and cost over a time period of baseline (1day), 3, 6, 9 and 12 months.Methods: Twenty-six hypomineralized first permanent molars from children aged 7-12 years indicated for full coverage restorations were randomly selected from the Out Patient Department. The selected teeth (molars) were then randomly allocated into two groups (13 each) according to the type of crown used, namely Group A-prefabricated zirconia crowns (n=13) and group B-custom-made zirconia crowns (n=13). Tooth preparation was done according to the crown selected and all the crowns were cemented using resin-based cement. Patients were recalled and the follow-up was done by single trained examiner.Results: Clinical success for both the crowns were similar with no statistical difference between them.Conclusions: Both the crowns proved to be clinically successful.

Molar-incisor hypomineralisation combat: exploratory qualitative interviews with general dental practitioners in England regarding the management of children with molar-incisor hypomineralisation.

Introduction Molar-incisor hypomineralisation (MIH) presents as a spectrum, with severe cases becoming increasingly complex to manage. This study aimed to investigate the perceptions and experience of general dental practitioners (GDPs) in England when managing children with MIH.Method Semi-structured telephone interviews with GDPs who regularly treat children took place in May 2020. A sample of four male and six female GDPs with 1-15 years of experience was achieved through purposively sampling interested parties following advertisement via professional groups. Thematic analysis using a realist and inductive approach was used in analysis.Results The overarching theme was of managing uncertainty, with four subthemes: setting the scene; fighting the tooth; working within the system; and self and interpersonal insight. Despite being knowledgeable, participants expressed varying levels of confidence in many aspects while managing children with MIH. There was a great deal of uncertainty surrounding 'doing the right thing' across the themes. Systemic barriers to managing children with MIH within the general dental service were identified.Conclusion The challenges of managing children with MIH was experienced as 'uncertainty'. Barriers within the general dental service made managing children with MIH difficult and participants relied on colleagues in secondary care to manage severe cases.

Molar-incisor hypomineralisation: Knowledge and perception of Syrian undergraduate and postgraduate dental students.

Dentists' knowledge and expertise, especially in their early career, are primarily shaped during undergraduate studies. This cross-sectional study aimed to assess the knowledge and perception of Syrian under- and postgraduate students regarding diagnosing and managing molar-incisor hypomineralisation (MIH)-affected teeth. Final-year dental students (FY-students), postgraduates in paediatric dentistry (PD-postgraduates) and postgraduates in other lines of specialty (OS-postgraduates) in all Syrian dental schools were invited to participate in an established web-based survey covering the knowledge and attitudes regarding the prevalence, aetiology, diagnosis and management of MIH. Data were analysed with descriptive statistics and Fisher's exact/chi-squared tests at 5%. In total, 1142 post- and undergraduate students from six public and five private dental schools in Syria participated in this study (867 FY-students, 74 PD-postgraduates and 201 OS-postgraduates). PD-postgraduates were found to present statistically significantly better knowledge regarding MIH compared with the two other groups. Only 19% of FY-students and 54% of OS-postgraduates reported themselves familiar with MIH (compared with 97% of PD-postgraduates). Similarly, 18% of FY-students and 27% of OS-postgraduates were capable of diagnosing MIH (compared with 81% of PD-postgraduates). Stainless-steel crowns and direct composite fillings were chosen as most suitable for treating MIH-affected molars from all responders. FY-students and even OS-postgraduates in Syria lack knowledge and confidence when confronted with MIH. The university curricula need to include more educational materials to equip the students with the necessary tools to manage MIH clinically.

Artificial intelligence-based diagnostics of molar-incisor-hypomineralization (MIH) on intraoral photographs

ObjectiveThe aim of this study was to develop and validate a deep learning–based convolutional neural network (CNN) for the automated detection and categorization of teeth affected by molar-incisor-hypomineralization (MIH) on intraoral photographs.Materials and methodsThe data set consisted of 3241 intraoral images (767 teeth with no MIH/no intervention, 76 with no MIH/atypical restoration, 742 with no MIH/sealant, 815 with demarcated opacity/no intervention, 158 with demarcated opacity/atypical restoration, 181 with demarcated opacity/sealant, 290 with enamel breakdown/no intervention, 169 with enamel breakdown/atypical restoration, and 43 with enamel breakdown/sealant). These images were divided into a training (N = 2596) and a test sample (N = 649). All images were evaluated by an expert group, and each diagnosis served as a reference standard for cyclic training and evaluation of the CNN (ResNeXt-101–32 × 8d). Statistical analysis included the calculation of contingency tables, areas under the receiver operating characteristic curve (AUCs) and saliency maps.ResultsThe developed CNN was able to categorize teeth with MIH correctly with an overall diagnostic accuracy of 95.2%. The overall SE and SP amounted to 78.6% and 97.3%, respectively, which indicate that the CNN performed better in healthy teeth compared to those with MIH. The AUC values ranging from 0.873 (enamel breakdown/sealant) to 0.994 (atypical restoration/no MIH).ConclusionIt was possible to categorize the majority of clinical photographs automatically by using a trained deep learning–based CNN with an acceptably high diagnostic accuracy.Clinical relevanceArtificial intelligence-based dental diagnostics may support dental diagnostics in the future regardless of the need to improve accuracy.

Major clinical results of the application of icon® in dental enamel hypoplasia: a systematic review

Introduction: In the scenario of dental enamel hypoplasia, Molar Incisor hypomineralization (MIH) represents qualitative enamel developmental defects. The prevalence of MIH is approximately 13% worldwide. In addition, children affected by MIH undergo dental treatment on their first permanent molars nearly ten times as often as children without MIH. Objective: It was to carry out a systematic review of clinical studies on the use of ICON® in dental enamel hypoplasia, to discuss the advantages of this resin in patients. Methods: The present study followed a systematic review model, following the rules of systematic review – PRISMA. The search strategy was performed in the PubMed, Cochrane Library, Web of Science and Scopus, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 122 articles were found. A total of 46 articles were fully evaluated and 25 were included in this study. Based on recent findings in the literature, the aesthetic results of ICON® infiltration proved to be effective, both in visual qualitative and quantitative spectrophotometric assessment. Furthermore, the infiltration of ICON® positively influenced the maintenance of the structural integrity of teeth affected by MIH, reducing the risk of enamel breakage. It also proved to be a minimally invasive treatment for tooth discoloration, less aggressive than conventional procedures. In addition to masking enamel white spot lesions, resin infiltration can involve residual enamel crystallites forming a hybrid enamel layer. Regarding the highest penetration and the highest percentages of penetration area, ICON® proved to be better than other resins such as Biscover LV (Bisco), Optiguard (Kerr Hawe), and Permaseal (Ultradent).

Maternal vitamin D status in pregnancy and molar incisor hypomineralisation and hypomineralised second primary molars in the offspring at 7–9 years of age: a longitudinal study

PurposeThe study aimed to investigate associations between maternal vitamin D status during pregnancy and molar incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) among children.MethodsThe study had a longitudinal design using prospectively collected data from 176 mother and child pairs. Mothers were initially recruited in a randomised controlled trial to assess a pregnancy exercise programme. Along with the 7-year follow-up, we invited the children to a dental examination. The exposure variable was maternal serum 25-hydroxyvitamin D in gestational weeks 18–22 and 32–36, categorised as insufficient (< 50 nmol/l) and sufficient (≥ 50 nmol/l). Negative binomial hurdle models were used to analyse potential associations between the exposure variables and MIH or HSPM. The models were adjusted for potential confounders.ResultsAmong the children (7–9 years old), 32% and 22% had at least one tooth with MIH or HSPM, respectively. A significant association was found between insufficient maternal vitamin D measured in gestational weeks 18–22 and the number of affected teeth among those with MIH at 7–9 years (adjusted RR = 1.82, 95% CI 1.13–2.93).ConclusionConsidering any limitations of the present study, it has been shown that insufficient maternal serum vitamin D at mid-pregnancy was associated with a higher number of affected teeth among the offspring with MIH at 7–9 years of age. Further prospective studies are needed to investigate whether this finding is replicable and to clarify the role of maternal vitamin D status during pregnancy and MIH, as well as HSPM, in children.