Prevalence of molar incisor hypomineralization (MIH) in Singaporean children.

BACKGROUND: There is a lack of data on molar incisor hypomineralization (MIH) in Asia, but this is not an indication that MIH is rare in the Asian population. Early identification of MIH is important as affected teeth frequently display post-eruptive enamel loss which would result in rapid caries progression. AIM: This objective of this study was to assess the prevalence of MIH in Singaporean children. DESIGN: Patients were recruited from 30 schools across Singapore. All children were examined by a single dentist, and the judgement criteria used were based on the 2003 European Academy of Paediatric Dentistry criteria. RESULTS: A total of 1083 children; average age of 7.7 ± 0.3 years were examined. One hundred and thirty-five children (12.5%) had MIH. A significantly higher proportion of children of the Malay ethnicity had MIH, compared to Chinese children (P = 0.02). Post-eruptive enamel breakdown and the presence of atypical restorations were correlated with increasing number of MIH teeth/child (Rho= 0.599, P < 0.001) and the cumulative enamel opacity colour score (Rho = 0.601, P < 0.001). CONCLUSIONS: Our findings suggest the role of ethnicity in MIH occurrence and that MIH severity may be influenced by the number of MIH teeth/child and the cumulative enamel opacity colour score.

Hipoplasia do esmalte: fundamentos para nomenclatura e identificação dos tipos e causas / Enamel hypoplasia: nomenclature foundations and identifications of types and causes

Quando as manchas e os defeitos no esmalte são nominados incorretamente, significa que as verdadeiras causas e mecanismos foram ignorados e uma abordagem terapêutica inadequada pode ser aplicada4. A formação do esmalte, ou amelogênese, é executada exclusivamente pelos ameloblastos, células altamente especializadas, que: produzem a matriz orgânica adamantina; mineralizam-o de uma forma muito específica, para resultar nos prismas; proporcionam uma estrutura altamente cristalina, ao reabsorverem as proteínas anteriormente incorporadas. A atividade do ameloblasto exige um grande refinamento metabólico, estrutural e organizacional, a ponto de ser considerado uma das células mais sensíveis frente aos agentes externos.

Health status among prehistoric Eskimos from Point Hope, Alaska.

Using the protocol outlined in The Backbone of History: Health and Nutrition in the Western Hemisphere (BBH) (Steckel and Rose. 2002a. The backbone of history: health and nutrition in the Western Hemisphere. Cambridge: Cambridge University Press), this project compares the Mark I Health Index (MIHI) scores of the Ipiutak (n = 76; 100BCE-500CE) and Tigara (n = 298; 1200-1700CE), two samples of North American Arctic Eskimos excavated from Point Hope, Alaska. Macroscopic examination of skeletal remains for evidence of anemia, linear enamel hypoplasias (LEH), infection, trauma, dental health, and degenerative joint disease (DJD) was conducted to assess differences in health status resulting from a major economic shift at Point Hope. These data demonstrate that despite differences in settlement pattern, economic system, and dietary composition, the MIHI scores for the Ipiutak (82.1) and Tigara (84.6) are essentially equal. However, their component scores differ considerably. The Ipiutak component scores are suggestive of increased prevalence of chronic metabolic and biomechanical stresses, represented by high prevalence of nonspecific infection and high frequencies of DJD in the hip/knee, thoracic vertebrae, and wrists. The Tigara experienced more acute stress, evidenced by higher prevalence of LEH and trauma. Comparison of overall health index scores with those published in BBH shows the MIHI score for the Ipiutak and Tigara falling just above the average for sites in the Western Hemisphere, adding support to the argument that the human capacity for cultural amelioration of environmental hardships is quite significant.

The prevalence of Molar-Incisor Hypomineralisation (MIH) in Wainuiomata children.

OBJECTIVES: The aim of this study was to determine the prevalence of Molar-Incisor Hypomineralisation (MIH) in Wainuiomata children and describe differences in prevalence among Maori, Pacific Island and New Zealand European ethnic groups. DESIGN: Cross-sectional survey of developmental defects of enamel in a random sample of children attending primary school in Wainuiomata, Wellington. METHOD: Study information and consent forms were sent to 850 7-to-10-year-old schoolchildren. Using the modified Developmental Defects of Enamel index, a single paediatric dentist examined students in the classroom. Dental caries experience was recorded as decayed, missing or filled primary and permanent teeth. RESULTS: Examinations were conducted on 522 children (participation rate 61.4%). The mean age of the children was 8.2 years (range 7 to 10 years). MIH prevalence was 14.9%. The prevalence ofhypomineralisation ofany tooth was 15.3%, and that for hypoplasia was 4.0%. There was no statistically significant ethnic difference in MIH prevalence. The mean DMFT was 0.16 (SD, 0.54) in those without a developmental defect, 0.54 (SD, 1.12) in those with hypomineralisation and 1.85 (SD, 1.85) in those with hypoplasia (p < 0.01). CONCLUSIONS: Approximately one in seven Wainuiomata children have MIH. Ethnicity is not a modifying factor in the occurrence of developmental defects of enamel. The presence of hypomineralisation and/or hypoplasia was associated with significantly greater caries experience in the permanent dentition.

Molar incisor hypomineralization in Hong Kong Chinese children.

BACKGROUND: Most prevalence studies on molar incisor hypomineralization (MIH) were carried out in European countries, and data from the East-Asian populations were lacking. AIM: This study aimed to investigate the prevalence of MIH in Hong Kong Chinese children. DESIGN: Since 2006, charting of teeth with MIH was included into the routine dental examination in a school dental clinic. The dental records of grade 6 primary school children who attended annual check-up in this clinic in 2006 were subsequently reviewed retrospectively. The records were selected for this study if the charting indicated that the children were affected by MIH. RESULTS: A total of 2635 records were reviewed and 73 cases of MIH were identified. The prevalence of MIH in this group of children was 2.8%. Their mean age was 12, and the male-to-female ratio was 1 : 1.2. The mean decayed, missing, or filled permanent teeth value of those affected was 1.5, which was higher than that of the general Hong Kong Chinese children aged 12 years old (0.8). A total of 192 teeth were affected. The most commonly affected teeth were permanent maxillary first molars, followed by mandibular first molars and maxillary central incisors. Dental fillings and fissure sealants were found in 52 (38%) and 65 (47%) permanent first molars with hypomineralization, respectively. Medical histories were unremarkable in 60 children, whereas early childhood diseases were reported in 13 cases. CONCLUSIONS: The prevalence of MIH in the permanent dentition of Hong Kong Chinese children was 2.8%. Children with MIH showed higher caries experience in the permanent dentition than the general population of similar age.

The prevalence of enamel opacities in permanent teeth of 11-12 year-old school children in Kuala Lumpur, Malaysia.

OBJECTIVE: To determine the prevalence, distribution, severity and treatment need of enamel opacities among 11-12 year-old school children in a fluoridated urban community. DESIGN: A cross-sectional descriptive survey of enamel opacities in 11-12 year-old schoolchildren. CLINICAL SETTING: A questionnaire survey and a clinical examination of erupted teeth using the Modified DDE Index was conducted on schoolchildren in randomly selected schools. PARTICIPANTS: 957 schoolchildren from government schools in Kuala Lumpur comprising the three major ethnic groups of Malay, Chinese and Indian children. MAIN OUTCOME MEASURES: The severity of enamel opacities was assessed by the extent of buccal surface involvement. Normative treatment need was based on severity of opacities. RESULTS: Enamel opacities were found in 90.7% of subjects and 47.2% of teeth. Malays have the highest prevalence with Chinese the least. Although ethnic differences is statistically significant (p < 0.01), the differences in prevalence between ethnicity is small. The most common type of defect was "diffuse opacities" (88.6% of subjects). Most subjects (70%) showed bilateral distribution of diffuse opacities indicating a systemic disturbance. Posterior teeth were twice more commonly affected (p < 0.05). The majority of opacities in anterior teeth (66.7%) were minor, involving less than 1/3 of the labial surface. Only 0.6% of the whole sample required some form of aesthetic intervention. CONCLUSION: Despite the high prevalence of enamel opacities, the degree of severity is very mild with only minimal aesthetic and public health concern.

Linear enamel hypoplasia and historical change in a central Australian community.

BACKGROUND: The current study extends the use of linear enamel hypoplasia (LEH) to examine the historical changes in living conditions encountered by Aboriginal people at Yuendumu who were born between 1890 and 1960. LEH provides health information beyond written records and gives information beyond written records and gives insight into the relationship between individual health and living conditions during initial and ongoing contact with Europeans. MATERIALS AND METHODS: The dental casts of 446 people, collected as part of the University of Adelaide longitudinal study of growth and development, were recorded for the presence of hypoplastic defects. Defects were recorded according to the Development Defects of the Enamel (DDE) standards and assigned to developmental units based on their crown position. RESULTS: The frequency of LEH on the permanent dentitions increased five-fold from the 1890-1929 birth cohort to the 1955-1960 cohort. LEH also affected earlier developing enamel units. Deciduous defects did not show a strong temporal trend but overall prevalence was comparable to other disadvantaged groups. CONCLUSION: The changes in permanent LEH frequency and age distribution correspond to altered living conditions with the worst hypoplasia recorded after settlement of Aboriginal people at Yuendumu. Prior to that period LEH was comparable to precontact Australian populations indicating that resettlement had a dramatic impact on childhood morbidity.

Invisible impacts but long-term consequences: hypoplasia and contact in central Australia.

The dental casts taken of Aboriginal people resident at Yuendumu, Central Australia, between 1950-1970 preserve a unique historical record of defects of the dental enamel (DDEs) among people born from 1890-1960 (n = 377). These data are used, in comparison with precontact data, to trace the chronological changes in childhood development that occurred among Aboriginal people from the point of initial engagement with white settlers to a period of overwhelming government control. The results demonstrate very little change in the frequency of DDE from the precontact period to 1929 but increases after that time, particularly after the forcible settlement of people on a government establishment at Yuendumu in 1946. Apart from the absolute increase in frequency, it is also clear that population variation decreased markedly, with growing numbers of children experiencing multiple defects in early childhood (ca. 0.8-1.5 years of age). The results also indicate that an early onset of DDE constituted a risk for further episodes. These changes in DDE correspond to periods of increasingly intense contact between Aboriginal people and Europeans and with changes to government policy aimed at assimilating the indigenous population. Such policies had marked costs for childhood development. The lack, however, of a visible marker of initial contact demonstrates the importance of the intensity of and motives behind interactions between indigenous and colonial populations in determining the health consequences of colonial encounters.

Well-being changes in response to 30 years of regional integration in Maya populations from Yucatan, Mexico.

Infant mortality rate (IMR), overall frequency of linear enamel hypoplasia (LEH), sexual dimorphism in LEH, age of onset of LEH, and age at menarche were used as indicators to test the hypothesis that the origin and development of the tourist industry and increased state participation on Maya subsistence agriculturists in the early 1970s had improved the well-being of the Maya. Two historical moments where inferred from the data. The first was derived from cheap and effective immunization and sanitation campaigns that reduced IMR from 143.4/1,000 live births in the early 1960s to 97.4 in the early 1970s. State participation broke the undernutrition-disease cycle enough to reduce LEH frequencies significantly (from 71.9% in individuals born before 1971 to 51.5% in those born in 1971 or after, chi(2) = 55.72; 1 df; alpha = 0.00001) and to eliminate the sex difference in LEH expression (from a 14.8% LEH difference between men and women before 1971 [Male/Female Odds Radio = 0.45, alpha significant at 0.05] to a nonsignificant 2% difference). Improvement in overall living conditions reflected in a "modern stage" infant mortality regime and an almost disappearance of LEHs, resulted from gradual improvements in living conditions that did not become apparent until the 1980s. Trends in the age at menarche are not statistically significant, probably due to methodological limitations. However, if overall living conditions continue to improve or stay as they are today, accelerations in maturation should become noticeable.

Frequency and chronological distribution of dental enamel hypoplasia in enslaved African Americans: a test of the weaning hypothesis.

The dentition of 27 enslaved African Americans from archaeological sites in Maryland and Virginia were examined. All 17 males and 7 of the 10 females in this study exhibited enamel hypoplastic defects indicative of systemic nutritional and disease stresses interfering with amelogenesis. Estimates of the ages of occurrence of these defects show that most occur between 1.5 and 4.5 years of age, 0.5-3.75 years later than historically documented weaning age (9-12 months of age) in similar plantation populations. Comparisons are made with studies of dental enamel hypoplasia in contemporaneous enslaved and free African American populations, including our data on 75 individuals from the First African Baptist Church cemetery in Philadelphia. These populations were highly stressed. While there appears to be a modest effect of early weaning stress, no direct relationship of peak frequencies to weaning age can be shown. These data raise questions about the attribution of peak hypoplasia frequencies to age at weaning or "post-weaning" stresses in previous paleopathological studies. High hypoplasia frequencies during the middle years of enamel development are more likely the result of a combination of 1) multiple environmental stresses, 2) differences in hypoplastic susceptibility in enamel, and 3) random factors.

Enamel hypoplasia and dental caries in Australian aboriginal children: prevalence and correlation between the two diseases.

This study investigated the prevalence of enamel hypoplasia and dental caries and the relationship between the two diseases in all 4- to 6-year-old Australian Aboriginal children of the Tiwi tribe on Bathurst Island. Seventy-nine of 80 children (99%) had enamel hypoplasia, with a mean of 12.0 +/- 4.1 hypoplastic teeth per child. Dental caries was noted in 66 (83%) of children and the mean number of decayed teeth per child was 3.9 +/- 3.3. A strong association between enamel hypoplasia and dental caries (P < 0.01) suggests that enamel hypoplasia may be a significant caries risk factor in this group. Furthermore, while high levels of medical morbidity were found, the relative importance of each medical condition in the pathogenesis of enamel hypoplasia could not be determined because nearly all patients with enamel hypoplasia had the full range of medical problems. It is likely that all the medical conditions commonly encountered contribute to enamel hypoplasia and may act synergistically.

Effects of ethnicity and birth month on localized enamel hypoplasia of the primary canine.

Localized enamel hypoplasia of the primary canine (LHPC) is produced by a different mechanism from that causing linear enamel hypoplasia, and yet contributes disproportionately to epidemiological studies of enamel hypoplasia in childhood that do not separate the two etiological types. LHPC results from impact, probably self-inflicted by infants mouthing objects, to the unerupted primary canine crown through abnormally fenestrated cortical bone overlying the crypt. Examination of the primary teeth of ninety-six children whose mothers were enrolled in the Healthiest Babies Possible Program in Vancouver showed an average prevalence of 31 percent with LHPC (ranging from 19 percent in Vietnamese Canadians to 56 percent among Indocanadians). This is much higher than previously reported for unselected samples from Vancouver, but equivalent to studies in the USA. Mean hours of sunshine in the birth month of children with LHPC is 141.7 hours and those without is 169.4 hours; the difference is statistically significant (p = .0383). Seasonal increase in food costs and reduced availability of fresh foods containing vitamin A are thought to contribute to facial osteopenia predisposing the infant to LHPC.

Prevalence of primary canine hypoplasia of the mandibular teeth.

The purpose of this study was to determine the prevalence of an uncommon lesion of the primary mandibular canines (primary canine hypoplasia), and its association with age, race, gender, dental caries, fluoridation status of the drinking water, breast-feeding, and geographic location. The study population comprised 2686 randomly selected children, black and white, 4 and 8 years old, who were enrolled in accredited private and public preschools and elementary schools in Mississippi. There were 1318 males and 1368 females, 1289 white children and 1397 black children, 1353 4-year-olds and 1333 8-year-olds. Results indicate that an association exists for race (P = 0.0001), gender (P = 0.01), and dental caries (P = 0.0001), but not for age (P = 0.07), geographic location (P = 0.73), fluoridation status of the water supply (P = 0.145), or breast-feeding (P = 0.392). The prevalence rate of primary canine hypoplasia was 33.2% for black children and 17.2% for white children. These data indicate that this lesion is significantly more prevalent in blacks than whites, and that teeth with this lesion have a greater probability of developing dental caries.

Hypocalcification and hypoplasia in permanent teeth of children from different ethnic groups in South Africa assessed with a new index.

A new descriptive index, the HHI (hypocalcification-hypoplasia index), is described for comparing enamel defects in groups of people. The index was used in a study completed in 1986, in which 1251 11-year-old children from different ethnic groups resident in South Africa were examined: 210 rural black, 203 urban black, 206 urban colored, 426 urban Indian, and 206 urban white. The index can be used as a screening examination, and the results from these different ethnic groups are presented.

Labial hypoplasia of primary canines in black Head Start children.

During routine examinations of 334 black Head Start children in Mississippi, many presented with areas of hypoplasia on the labial surfaces of the mandibular primary canines. Mean prevalence was 38 percent in fluoridated areas and 36 percent in areas without fluoridation. As it appears that hypoplastic defects have a strong potential to become carious, one should expect that the incidence of 25 percent reported here would continue to increase.

Developmental enamel defects of the primary dentition in a group of Californian children.

The parent of each three- to six-year old child with enamel defects, seen at the Loma Linda University School of Dentistry between 1981 and 1982, was interviewed to find an explanation for the defect. The most frequently given was hyperbilirubinemia.