Prenatal exposure to environmental toxins and comprehensive dental findings in a population cohort of children.

Environmental toxins are known to have many impacts on growth and development in humans, starting in utero. Alterations in amelogenesis, caused by chemical and physical trauma that occur during the antenatal, perinatal and postnatal time periods, may result in developmental defects in deciduous and permanent tooth enamel, as demonstrated in animal studies. These defects can be clinically visible and result in a variety of morphological and functional problems in the dentition. Since enamel does not remodel after formation, it may serve as a permanent record of insults during organ development.Our primary purpose was to investigate any possible relationship between intrauterine exposure to endocrine disrupting chemicals (phenols and phthalates) and developmental defects in enamel in children, while also accounting for fluoride exposure. Our secondary purpose was to report descriptively on findings from comprehensive dental examinations performed on 356 children that were drawn from the general paediatric population. A cohort of children from the Utah Children's Project (N = 356) that had full medical exams, comprehensive medical and family histories and available biospecimens were given extraoral and intraoral examinations. They also completed an oral health questionnaire. Standardized intraoral photographs were taken of the teeth and viewed by standardised examiners and the dental observations were recorded for a full inventory of findings, including: tooth morphology, caries, restorations, colorations, attrition, erosion, fractures and hypomineralization. Perinatal maternal urine samples were assessed for the concentration of fluoride, phenols and phthalates, including bisphenol A (BPA).Pairwise statistical analyses were done to correlate the dental findings with one another and with the presence of environment chemicals found in the urine samples. Hypomineralization was the most common finding (96% of children; 37% of deciduous teeth, 42% of permanent teeth), consistent with molar incisor hypomineralization (MIH) described in other human populations. No consistent correlations were seen between dental findings and the presence of phenols and phthalates in prenatal urine, but the number of samples available for the assessment was limited (n = 35).In conclusion, we found a high proportion of dental hypomineralization in a population based paediatric cohort, but did not find an association with prenatal exposure to phenols and phthalates.

Does information about MIH on dental homepages in Germany offer high quality? A systematic search and analysis.

PURPOSE: The internet is increasingly used to seek health information. A dental condition of increasing concern and public interest is molar incisor hypomineralisation (MIH), why we evaluated the information quality of German dentists 'websites on the topic of MIH. METHODS: A systematic search was performed by two independent investigators using three search engines. The information content of websites on MIH and technical, functional aspects, overall quality, and risk of bias were assessed using validated instruments (LIDA, DISCERN). Practice-related characteristics (practice type, specialization, setting, number and mean age of dentists) were recorded, and associations of these characteristics with websites' overall quality were explored using multivariable linear regression modelling. RESULTS: 70 sites were included. 52% were multipractices in urban areas (49%). The most common age group was middle-aged individuals (41-50 years). The average number of dentists/practice was 2.5. The majority met more than 50% of the DISCERN and LIDA criteria (90%, 91%). The MIH definition was frequently used (67%), MIH symptoms were described (64%), and 58% mentioned therapies. The prevalence of MIH was mentioned less frequently (48%). MIH example photographs were rarely shown (14%). In multivariable analysis, most practice-related factors were not significant for overall site quality. Only chain practices had slightly higher quality in this regard (2.2; 95% CI of 0.3-4.1). CONCLUSIONS: MIH is mentioned on a large proportion of dentists' websites. Overall technical, functional, and generic quality was high. Risk of bias is limited. While most websites provided a basic definition of MIH and its symptoms, important information for patients was missing.

The prevalence of developmental defects of enamel in a cohort of adults with cystic fibrosis - A cross sectional study.

OBJECTIVES: Cystic Fibrosis is an autosomal recessive condition. It is a multisystem disease treated with a broad range of pharmacological therapies, diet and nutrition, and physiotherapy. Previous studies suggest that people with cystic fibrosis have a higher prevalence of developmental defects of enamel which may place this population at a greater risk of developing oral diseases such as caries. The aim of this study was to assess a cohort of people with cystic fibrosis (PwCF) for the presence of developmental defects of enamel and compare the results with a control group of people without cystic fibrosis. METHODS: A cross sectional study involving 92 participants with cystic fibrosis and 92 controls was conducted in Cork University Dental School & Hospital. All participants completed a detailed questionnaire prior to undergoing a full clinical examination. The Developmental Defect of Enamel Index was used as a measurement index. All data was statistically analysed with the help of statisticians from Cystic Fibrosis Registry of Ireland. RESULTS: 64 % (n = 59) of PwCF had enamel defects compared to just 30 % (n = 28) of people without cystic fibrosis. The median number of teeth affected by enamel defects in the study group was 1.5, compared to 0 in the control group. CONCLUSION: In this study the cohort of PwCF had more enamel defects than people without CF. Further research is required to investigate the aetiology of these findings. CLINICAL SIGNIFICANCE: Clinicians should be vigilant after teeth have erupted in PwCF as they may have an increased susceptibility to developmental defects of enamel.

Molar-Incisor Hypomineralisation: Severity, caries and hypersensitivity.

OBJECTIVES: To investigate distribution of affected teeth and severity of molar-incisor hypomineralisation (MIH) in 8-9-year-old children. A second aim was to study association between severity of MIH and hypersensitivity, caries, and affection of incisors and second primary molars (SPM). METHODS: A total of 3013 children in one age cohort participated in a cross-sectional study, of which 851 children were diagnosed with MIH. A majority of these children were re-examined and MIH diagnosis based on the European Academy of Paediatric Dentistry criteria was confirmed in 538 children. The re-examinations were undertaken at the local clinics by one calibrated dentist. Data were tested with bivariate logistic regression analysis. Results were reported using frequencies, proportions, odds ratios (OR) and confidence intervals (CI). RESULTS: Almost half of the children with MIH (46.8 %) had at least one severely affected molar. Incisors were affected in 51.9 % of children with MIH, and the prevalence was higher in children with severe affection (57.4 %, p < 0.01). Among children with MIH, second primary molars were affected in 29.6 %, hypersensitivity in at least one first permanent molar was reported by 25.8 and 30.8 % had caries extending to dentine. Children classified with severe MIH were more likely to suffer from hypersensitivity (OR 5.62, 95 % CI 3.61-8.74) and dentine caries (OR 10.32, 95 % CI 6.46-16.50) than children with mild MIH. CONCLUSION: Prevalence of hypomineralised incisors and SPM were high in the studied children with MIH. Children with severe MIH had higher probability of incisor affection, dentin caries and hypersensitivity. CLINICAL SIGNIFICANCE: This study highlights the importance of understanding the association between MIH, caries and hypersensitivity, especially in children with severe MIH. These children need extensive and individualized care in the dental services to prevent caries and pain.

"Ethnic disparities in the prevalence of Molar-Incisor-Hypomineralisation (MIH) and caries among 6-12-year-old children in Catalonia, Spain".

AIM: To study the prevalence of MIH and caries in 6- and 12-year-old schoolchildren and their association with ethnic disparities and other relevant factors. BACKGROUND: In recent years, there has been uneven improvement in school children's oral health, highlighting inequalities in access to dental care and health outcomes, particularly among ethnic minorities. The most prevalent oral disease in childhood, caries, is preventable, as its risk factors are well known. However, MIH, a common condition affecting the enamel of permanent incisors and/or molars, has no established aetiology or preventive measures. METHODS: A cross-sectional study among schoolchildren was conducted in 725 children from Masnou (Barcelona, 2013) and in 577 children from Sant Andreu de Llavaneres (Barcelona, 2018-2020). Data collection was carried out by means of clinical examination and a selfreferenced questionnaire. Oral health outcomes included: presence of dental caries, presence of MIH, hypomineralised second primary molars (HSPM). All variables were analysed according to ethnic disparities and other variables such as socioeconomics, diet, hygiene habits, plaque and access to dental services. We performed multivariate Poisson regression models with robust variance to examine ethnic disparities in MIH and caries. CONCLUSION: This cross-sectional study based in Catalonia, Spain showed that there are ethnic disparities in caries as observed with other child's diseases; however, they do not seem to follow the same pattern for MIH. More studies are needed (i) to explore how MIH behaves among populations in terms of inequality; (ii) to study the aetiological factors of MIH; and (iii) to identify potential factors associated with MIH and caries that have not been studied and that may contribute to the observed ethnic disparities.

Caries experience in children with molar-incisor hypomineralisation in Fujairah, United Arab Emirates and its association with hypomineralised teeth number.

BACKGROUND: Molar-incisor hypomineralisation (MIH) has been found associated with an increase in dental caries. Studies utilising the recent MIH diagnosis and calibration criteria recommended by the EAPD in 2021 are very scarce. Additionally, the available data in literature about the relationship between the hypomineralised teeth number (HTN) and caries come from only one study. PURPOSE: To assess the relationship between MIH and caries experience among children in the city of Fujairah, UAE, utilising the recent criteria recommended by the European Academy of Paediatric Dentistry (EAPD) in 2021, and to assess the relationship between the number of teeth affected with MIH, and dental caries. METHODS: One hundred and sixty-two children were included in this cross-sectional study, aged 7-9 years old. Children were examined for MIH according to Ghanim et al. (Eur Arch Paediatr Dent 16:235-246, 2015. 10.1007/s40368-015-0178-8) criteria and Ghanim et al. (Eur Arch Paediatr Dent 18:225-242. 10.1007/s40368-017-0293-92017) training manual. Caries experience was assessed with decayed, missing, filled (dmft, DMFT) scoring system. RESULTS: dmft mean was 6.56 (SD ± 3.78) and DMFT mean was 0.91 (SD ± 1.23). Children with MIH had significantly higher dmft (p = 0.003) scores. Children with higher HTN had significantly higher dmft (p = 0.008) scores. CONCLUSION: Children in Fujairah have extremely high caries scores. Children with MIH have more decayed, missing and filled teeth. Hypomineralised teeth number was positively associated with caries experience.

Prevalence and clinical presentation of molar incisor hypomineralisation among a population of children in the community of Madrid.

OBJECTIVE: The main objective of this study was to estimate the prevalence of molar incisor hypomineralisation (MIH), an alteration of tooth enamel with an estimated worldwide prevalence rate of 14%, among children using primary care services in the Community of Madrid, Spain. MATERIALS AND METHODS: This was a descriptive, cross-sectional and multicentre study. After calibrating all researchers and following the diagnostic criteria of the European Academy of Paediatric Dentistry (EAPD), children aged between 8 and 16 years who were users of the dental services at 8 primary oral health units of the Madrid Health Service (SERMAS) were included. The children underwent a dental examination, and the parents were asked to complete a questionnaire. RESULTS: The prevalence of MIH was 28.63% (CI: 24.61-32.65%). The age cohorts most affected by MIH were 8 years (21.4%) and 11 years (20.7%). The presence of MIH was greater among girls (85; 60.71%) than among boys (55; 39.28%). The mean number of affected teeth per patient was 4.46 ± 2.8. The most frequently affected molar was the upper right first molar (74.3%), and the upper left central incisor was the most affected incisor (37.85%). Opacities were the defects most frequently recorded (63.57%). CONCLUSIONS: The prevalence of MIH in this study is the highest of all relevant studies conducted in Spain.

Selective excavation and ozone therapy: new frontier of mini-invasive caries treatment in MIH paediatric patients. A case report.

BACKGROUND: The term hypomineralisation of molars and incisors (MIH), introduced in 2001 by Weerheijm et al., describes a clinical state of hypomineralisation of permanent molars with frequent involvement of the incisors. MIH is considered a global dental problem with a prevalence ranging from 2.4% to 40.2% in the entire world paediatric population. The continuous increase in the prevalence of enamel anomalies, including MIH, indicates the need to define new intervention protocols based on the technological advances that are revolutionising paediatric dentistry. The use of ozone associated with the selective and minimally invasive excavation of the dental tissue combines the antibacterial properties of the gas with an ultra-conservative approach aimed at the maximum conservation of the dental tissue. The operative protocol described can be an important tool in the prevention and treatment of MIH. The aim of this work is to illustrate an operative clinical protocol based on the combined use of selective excavation and ozone for the treatment of carious lesions in paediatric patients with MIH.

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.

Assessment of the developmental defects of the enamel in children and adolescents with sickle cell disease: A comparative study.

BACKGROUND: Sickle cell disease (SCD) is the most important hemoglobinopathy in terms of frequency and social impact and can affect the stomatognathic system. AIM: To assess and compare the developmental defects of the enamel (DDE) in children and adolescents with and without SCD. DESIGN: This was a cross-sectional, analytical, and comparative study of 210 children and adolescents aged 5-18 years, who visited the Hematology and Hemotherapy Hospital of Pernambuco. RESULTS: Developmental defects of the enamel were observed in 55.2% of the SCD patients and 35.2% of the non-SCD patients (healthy group; p < .05). In the SCD group, DDE were more common in females than in males (69.1% vs. 40.0%; p < .05). The incidence of DDE in the permanent teeth was higher in the upper arch than in the lower arch (SCD group, 13.1% vs. 4.6%; healthy group, 8.9% vs. 3.6%; p < .05). CONCLUSION: Compared with the healthy group, the SCD patients were almost twice as likely to develop DDE, mostly affecting females and the permanent teeth. These findings suggest that individuals with SCD need early dental care to avoid future oral problems.

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

BACKGROUND: The aim of this study was to determine whether there is any association between molar incisor hypomineralization and developmental dental anomalies. METHODS: Two pediatric dentists evaluated panoramic radiographs of 429 children aged 8-14 years with molar incisor hypomineralization (study group) and 437 children without molar incisor hypomineralization (control group) in terms of developmental dental anomalies. Twelve different developmental dental anomalies were categorized into four types: size (microdontia, macrodontia); position (ectopic eruption of maxillary permanent first molars, infraocclusion of primary molars); shape (fusion, gemination, dilaceration, taurodontism, peg-shaped maxillary lateral incisors); and number (hypodontia, oligodontia, hyperdontia) anomalies. RESULTS: No significant difference was observed in the frequencies of developmental dental anomalies between the study and control groups in total, females, and males (p > 0.05). A statistically significant difference was found between the distribution of developmental size, position, shape, and number anomalies between the study and control groups (p = 0.024). The most common anomaly in both groups was hypodontia (6.3% and 5.9%, respectively). There was a significant difference between the study and control groups in terms of subtypes of shape anomaly in all children and females (p = 0.045 and p = 0.05, respectively). CONCLUSIONS: While a significant difference was observed between the distributions of types of developmental dental anomalies between individuals with and without molar incisor hypomineralization, there was no difference in terms of the frequency of developmental dental anomalies.

Gestational Serum Retinol Deficiency Is Associated with Enamel Hypoplasia.

Enamel hypoplasia (EH) is a prevalent developmental defect of teeth that can result from various insults, including prenatal nutrient deficiencies. This study aimed to evaluate the association between prenatal serum retinol deficiency and EH in the deciduous teeth of offspring at 2-y of age. A cohort of 1,450 pregnant women was enrolled, and their prenatal nutritional status was assessed between 12 and 14 wk of gestation. Maternal serum retinol, serum 25-hydroxyvitamin D (25OHD), hemoglobin, body mass index, and birth outcomes, infant feeding practices, family socioeconomic status, and demographic information were recorded. Oral health examinations were conducted for the children semiannually, and EH was diagnosed using the Modified DDE index on all the surfaces of erupted teeth. A modified Poisson regression analysis was used to assess the cumulative risk of EH over a period of 2-y. A total of 920 (63.4%) mother-child pairs completed the study, and the cumulative EH prevalence among offspring after 2-y of follow-up was 16.5% (N = 152; 87/1,114 children in the first year and 132/920 in the second year, with 20/920 having EH only in the first year). After adjusting for potential confounders, maternal serum retinol deficiency significantly increased the risk of deciduous EH (risk ratio [RR], 2.0; 95% confidence interval [CI], 1.1-3.7). In addition, deficient serum 25OHD (RR, 6.5; 95% CI, 4.0-10.7), caesarean delivery (RR, 1.6; 95% CI, 1.0-2.4), Muslim (RR, 2.9; 95% CI, 2.0-4.1) and Christian (RR, 2.4; 95% CI, 1.6-3.5) versus Hindu religions, and very preterm birth (RR, 1.7; 95% CI, 1.1-2.9) increased the risk of EH. Children presenting with EH had 2 or more teeth affected, and the maxillary incisors were the most frequently affected, followed by the first primary molars and canines. In conclusion, maternal serum retinol deficiency during the 12 to 14 wk of gestation may increase the risk of deciduous EH, besides the well-established 25OHD deficiency.

Prevalence and severity of molar-incisor hypomineralization, is there an association with socioeconomic status? A cross-sectional study in Chilean schoolchildren.

PURPOSE: Data about molar-incisor hypomineralization (MIH) prevalence and its severity remains limited for some Latin American countries. Furthermore, its association with socioeconomic status (SES) is still unclear. Thus, this study aims to determine the prevalence and severity of MIH in Santiago, Chile and explore its association with SES. METHODS: A cross-sectional study with schoolchildren between 6 and 12 years was conducted. Children were evaluated using the European Academy of Paediatric Dentistry to diagnose MIH, and the Mathu-Muju and Wright criteria to determine its severity. RESULTS: A total of 1,270 children were included. The MIH prevalence was 12.8% without association with gender (p = 0.609). Prevalence was higher among schoolchildren ages 8 and 9 (p = 0.002), and in lower SES (p = 0.007). MIH mild cases were the most prevalent (63%), and severity was not related to gender (p = 0.656), age (p = 0.060), or SES (p = 0.174). CONCLUSIONS: The prevalence of MIH in the province of Santiago, Chile is 12.8% and was found to have a higher incidence in 8-9-year-old students and among those categorized by low SES. Furthermore, MIH prevalence was associated with low SES. IMPLICATIONS: Public health policies to address MIH in Chile should start with schoolchildren aged 8 to 9, and with low SES.

Molar-incisor hypomineralisation in Norwegian children: Prevalence and associated factors.

This study investigated the prevalence and associations of molar-incisor hypomineralisation (MIH) in 8-9 year-old children in Oslo. A total of 3013 children in one age cohort participated in the study during their regular dental examination at the Public Dental Service. Hypomineralised enamel defects were recorded according to the European Academy of Paediatric Dentistry criteria for MIH. Information on health and medications used during pregnancy and in the child's first 3 years of life was obtained from a questionnaire administered to parents. The overall prevalence of MIH was 28.2%, with no gender difference. A higher prevalence of MIH was found in children who had been ill or had used medication in early life and in those whose mother had been ill during pregnancy. No association was found between MIH and prematurity or maternal use of medication during pregnancy. The multivariable analyses showed that children with MIH were more likely to have suffered from illness in early life (OR = 1.41, 95% CI: 1.17-1.70), used antibiotics during the first year of life (OR = 1.68, 95% CI: 1.19-2.35), experienced tooth pain (OR = 1.33, 95% CI: 1.03-1.72), and experienced pain while toothbrushing (OR = 2.17, 95% CI: 1.46-3.23) than children without MIH. The prevalence of MIH was high in the children participating in this study.

Prevalence and severity of Molar-Incisor Hypomineralisation in children in Fujairah, United Arab Emirates.

AIM: This study aims to find the prevalence of MIH in children in the city of Fujairah, United Arab Emirates, utilising the current standardised guidelines for diagnosis and calibration. BACKGROUND: Molar-Incisor Hypomineralization (MIH) prevalence in paediatric patients has been widely studied. However, most of the available studies have utilised criteria that did not offer consistent diagnostic and calibration tools, which resulted in incomparable results. METHODS: Cross-sectional study. One hundred sixty-two school children aged 7-9 years in the city of Fujairah, UAE have been randomly selected and orally examined for the presence of MIH lesions. This was conducted following Ghanim et al. [2015] guidelines and after calibrating examiners following Ghanim et al. [2017] training manual. CONCLUSION: MIH prevalence was high in the city of Fujairah, UAE. More studies utilising the standardised criteria are required for valid comparisons. Further research on the aetiology of MIH is also needed.

Prevalence and associated factors of enamel developmental defects among Nigerian children with perinatal HIV exposure.

To evaluate the prevalence and pattern of developmental defects of the enamel (DDE) and their risk factors among children born infected with Human Immunodeficiency Virus (HIV) and those born to HIV-infected mothers compared with their unexposed counterparts (i.e., children born to uninfected mothers). This was an analytic cross-sectional study evaluating the presence and pattern of distribution of DDE in three groups of school-aged children (age, 4-11 years) receiving care and treatment at a Nigerian tertiary hospital, comprising: (1) HIV-infected (HI) on antiretroviral therapy (ART) (n = 184), (2) HIV-exposed but uninfected (HEU) (n = 186) and (3) HIV-unexposed and uninfected (HUU) (n = 184). Data capture forms and questionnaires were used to record the children's medical and dental history based on clinical chart review and recall from their parents/guardians. Dental examinations were performed by calibrated dentists blinded to the study grouping. CD4+ (Cluster of Differentiation) T-cell counts were assayed for all participants. The diagnosis of DDE corresponded with the codes enumerated in the World Dental Federation's modified DDE Index. Analyses relied on comparative statistics to determine risk factors associated with DDE. A total of 103 participants distributed among the three groups presented with at least one form of DDE, which indicated a prevalence of 18.59%. The HI group had the highest frequency of DDE-affected teeth (4.36%), while that of the HEU and HUU groups were 2.73% and 2.05%, respectively. Overall, the most encountered DDE was code 1 (Demarcated Opacity), accounting for 30.93% of all codes. DDE codes 1, 4 and 6 showed significant associations with the HI and HEU groups in both dentitions (p < 0.05). We found no significant association DDE and either very low birth weight or preterm births. A marginal association with CD4+ lymphocyte count was observed in HI participants. DDE is prevalent in school-aged children, and HIV infection is a significant risk factor for hypoplasia, a common form of DDE. Our results were consistent with other research linking controlled HIV (with ART) to oral diseases and reinforce advocacies for public policies targeted at infants exposed/infected perinatally with HIV.

Developmental enamel defects and their relationship with caries in adolescents aged 18 years.

Randomly selected 1,611 individuals aged 18 years formed a nationally representative sample from all provinces of Poland. Developmental defects of the enamel (DDE) and caries were assessed using the modified DDE index, molar incisor hypomineralisation (MIH) Treatment Need Index (MIH-TNI), FDI and WHO criteria by 22 trained and calibrated dentists. T-test was used for comparing group means. A simple and multiple logistic regression tests were used to assess the relationship between DDE and caries severity expressed as DMFT (p < 0.05). The prevalence of DDE was 13.7%. Demarcated opacities (DEO) were the most frequent (9.65%); 4% had diffuse opacities (DIO) and 1.5% had hypoplasia. MIH was diagnosed in 0.6% patients. The prevalence of caries was 93.2%, with mean DMFT of 6.50 ± 4.22. The DMFT value was 7.52 ± 4.77 in the group of patients with demarcated opacities (DEO); 7.85 ± 4.74 with diffuse opacities (DIO) and 7.56 ± 4.57 with enamel hypoplasia, respectively. There was a significant relationship between caries severity and DDE (p < 0.001), DEO (p = 0.001) and DIO (p = 0.038), and between DDE and DMFT index (p < 0.001). The results obtained in the study proved the significant relationship between DDE and DMFT in 18-year-olds, the assessment of which was the aim of the study.

Meaningful measures of enamel hypoplasia: Prevalence and comparative intensity of developmental stress.

OBJECTIVES: Developmental stress causing enamel thinning is an important topic in primate biology. Because taxa differ in growth rates and enamel thickness, the goal is to provide a new method allowing direct comparison of prevalence and salience of enamel defects among samples. MATERIALS AND METHODS: Casts of ape teeth spanning the Late Pleistocene to Late Miocene from three site areas of increasing seasonality, equator (Sumatra) to 20° (Vietnam) and 25°N latitude (China), were examined for enamel defects among paleo-orangutans (n = 571, 222, respectively) and Lufengpithecus lufengensis (n = 198). Frequency of affected teeth and number of linear enamel hypoplasia were recorded. Defect dimensions were measured with a confocal microscope. Simple prevalence is compared to weighted prevalence (%), calculated by dividing "number of LEH from specific tooth groups" by "specific tooth sample size"; this quantity divided by "tooth-specific years of imbricational enamel formation." Defect dimensions are reduced to a dimensionless index termed "enamel deficit ratio" through dividing "daily enamel deficit" by "daily secretion rate." RESULTS: Weighted prevalence increases to the North, highlighting latitudinal similarities. In contrast, "enamel deficit ratio," designed to express comparative severity of developmental stress among samples, was least in the high latitude sample and differed little between paleo-orangutan samples. DISCUSSION: The actual numbers generated are not as important as efficacy of the proposed methods for other taxa. Developmental stress appears least severe in the high latitude (Lufengpithecus) sample but affects a greater proportion, compared to paleo-orangutans. Regardless of findings, the proposed solutions to improve comparability of disparate samples, yield reasonable results.

Determination of dental caries, molar-incisor hypomineralization, and oral health-related quality of life in schoolchildren: A structural equation modeling approach.

BACKGROUND: Some oral conditions can have psychosocial consequences that affect children's daily life and well-being. AIM: To create a structural model for the determination of dental caries, molar-incisor hypomineralization (MIH), and the impact of these conditions and socioeconomic status on schoolchildren's oral health-related quality of life (OHRQoL). DESIGN: A representative cross-sectional study was conducted in Lavras, Brazil, with 1181 female and male schoolchildren 8-9 years of age. OHRQoL was measured using the Brazilian version of the CPQ8-10. Clinical examinations were performed by a calibrated dentist for the diagnosis of dental caries (WHO) and MIH (EAPD). Parents/caregivers answered questionnaires addressing the child's medical history and socioeconomic status. Data were analyzed using structural equation modeling. RESULTS: The model revealed that greater MIH severity (ß = .874; p < .001) and worse socioeconomic status (ß = -.060; p = .001) were associated with a greater number of teeth with caries experience. The higher the number of teeth with caries experience (ß = .160; p = .007) and worse socioeconomic status (ß = -.164; p < .001), the greater the negative impact on OHRQoL. CONCLUSION: The model created showed that dental caries and socioeconomic status had a direct negative impact on the OHRQoL of schoolchildren and MIH had an indirect impact mediated by the occurrence of caries experience.

The prevalence and characteristics of and the association between MIH and HSPM in South-Western France.

BACKGROUND: Molar-incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) involve qualitative structural developmental anomalies of tooth enamel, affecting the first permanent molars (FPM) and the second primary molars, respectively. This developmental anomaly of systemic origin has important consequences for oral health. AIM: To determine the prevalence of MIH and HSPM in south-western France and explore the distribution of hypomineralised lesions on permanent and primary molars. DESIGN: Amongst 856 children (aged 7-9 years) in schools randomly selected by the Academy of Bordeaux (Ministry of Education), the FPM, permanent incisors and the second primary molars were examined by two examiners trained and calibrated for the diagnostic criteria for MIH and HSPM of the European Academy of Paediatric Dentistry. RESULTS: Molar-incisor hypomineralisation was present in 160 children (18.7%) and HSPM in 81 children (9.5%); 4.9% had both HSPM and MIH (42 of 856). Hypomineralised lesions were present in 1-4 FPM in affected individuals (mean = 2.4) and were distributed in an asymmetrical manner with widely varying severity at the tooth and individual level. A child with HSPM was more likely to have MIH than a child without HSPM (95% CI OR = 6.0 [3.7-9.7]; p < .0001). CONCLUSION: Molar-incisor hypomineralisation and HSPM have three main asymmetrical characteristics: tooth location, severity of hypomineralisation and number of teeth affected.