Posteruptive tooth age and severity of dental fluorosis in Kenya

Abstract – The purpose of the present study was to assess whether the degree of severity of enamel changes in a population exhibiting rather severe dental fluorosis may be related to posteruptive tooth age and to describe the clinical manifestations of the enamel destructions. All permanent teeth in 102 children aged 10–15 yr who were born and reared in a 2 ppm fluoride area of Kenya were examined for dental fluorosis using the TF-Index. Clinically, at time of eruption all teeth appeared chalky white, but already prior to coming into occlusion discrete pits had formed. A variety of more extensive damages to the surface enamel was found in teeth already in occlusion. In particular, the maxillary incisors exhibited extensive artificial attrition for cosmetic reasons, which make these teeth unreliable for accurate scoring of severity in the present population. An analysis of the proportion of teeth exhibiting TF1-scores 4+, 5+ and 6+ showed that children aged 13–15 yr had a significantly greater proportion of teeth with TFI-scores >6 compared to children aged 10–12 yr (Wilcoxou, P <0.0001). This finding is unlikely to be a result of different fluoride exposures in the two age groups and indicates that even several years after eruption there is a trend towards an increasing severity of enamel surface destructions in children exhibiting pronounced degrees of subsurface enamel hypomineralization at time of eruption.     

Proportion and extent of manifestation of molar‐incisor‐hypomineralizations according to different phenotypes

Objective: This epidemiological study aimed to assess the proportion and extent of manifestation of enamel hypomineralization, including molar‐incisor‐hypomineralization (MIH), in the permanent and primary dentition. Methods: A total of 693 children enrolled in an ongoing birth cohort study (GINIplus‐10) were examined at their 10‐year follow‐up. Enamel hypomineralization was scored in the primary and permanent dentition on a tooth‐ and surface‐related level based on the criteria of the European Academy of Paediatric Dentistry (EAPD). Children were grouped according to their distribution pattern of enamel hypomineralization: children with a minimum of one hypomineralized tooth in the primary dentition (ht ≥ 1) and permanent dentition (HT ≥ 1); with a minimum of one hypomineralization on at least one first permanent molar (MIH); and with hypomineralization on at least one first permanent molar and permanent incisor (M + IH). For each group, the mean values of hypomineralized primary teeth (ht), permanent teeth (HT), and permanent surfaces (HS) were calculated. Results: The proportion of affected children was 36.5 percent (HT ≥ 1), 14.7 percent (MIH), and 9.4 percent (M + IH); 6.9 percent of the subjects had a minimum of one affected primary tooth (ht ≥ 1). The mean number of hypomineralized permanent teeth and surfaces were 2.3HT/2.9HS (HT ≥ 1), 3.4HT/4.8HS (MIH), and 4.2HT/5.9HS (M + IH). The mean number of hypomineralized primary teeth amounted to 0.1ht in the entire study population. Conclusions: Enamel hypomineralization can be detected frequently in this study sample. Children with M + IH showed the highest number of affected teeth and surfaces followed by those with MIH.     

Molar-incisor hypomineralization and oral hygiene in 10- to-12-yr-old Swedish children born preterm

Although preterm birth is associated with an increased risk of medical problems and impairments, there is limited knowledge of how this affects oral health. It was hypothesized that when 10-12 yr of age, children who were preterm at birth would present with a higher prevalence of molar-incisor hypomineralization (MIH), more dental plaque, and a higher degree of gingival inflammation than full-term control children. Eighty-two preterm children, born between 24 and 32 wk of gestation, and 82 control children, born between 37 and 43 wk of gestation, were clinically examined for developmental defects in enamel, MIH, dental plaque, and gingival health. In addition, behaviour management problems were evaluated. Information on any aetiological factors with a potential influence on MIH and oral health was collected via questionnaires. Molar-incisor hypomineralization was more common in preterm children than in controls (38% vs. 16%), as were enamel developmental defects (69.5% vs. 51%). Low gestational age and low birth weight increased the risk of MIH. Preterm children had more plaque, a higher degree of gingival inflammation, and more behaviour-management problems than controls. In conclusion, oral health problems were more common in preterm children than in control children.     

Enamel Opacities and Dental Esthetics

Objectives: The purpose of this study was to determine the esthetic importance of different types of developmental enamel defect. Methods : In the first method used, individual subjects from three different populations with less than 0.1, 0.7, and 0.9 ppm fluoride in their drinking water, were asked about the appearance of their teeth and results compared to assessments of clinical photographs made by a single examiner. In the second method used, dentist and lay observers were asked to assess the appearance of the dentition of selected individuals who had a range of enamel defects. Results : According to the first method, both the size of demarcated opacities and the degree of enamel hypomineralization (TF index) were related to satisfaction with appearance. However, there was no difference in satisfaction with the appearance of the teeth among the three areas included in this study. In the second method, similar types of enamel defects were found to be esthetic stimuli as with the first study, but the dentists responded more strongly to the stimulus of enamel hypomineralization than the lay examiners. Conclusions : Both demarcated opacities and enamel hypomineralization may be important when assessing differences between populations. Further, esthetic ratings by dentists may not be a suitable means of assessing the esthetic importance of different types of enamel defects.     

Amelogenesis imperfecta: a scanning electron microscopic and microradiographic study

The aim of the present study was to use scanning electron microscopy (SEM) to visualize the morphology of the enamel surface in 12 primary teeth from children with amelogenesis imperfecta (AI). The observations were correlated to genetic, clinical and microradiographic data from the same teeth and to non-affected control teeth. SEM showed similar disturbances in teeth with a clinical predominance of hypoplasias and in teeth with a predominance of hypomineralization. In the microradiographs the enamel of most teeth showed both hypoplasias and areas of hypomineralization, independently of the predominant clinical manifestation. In the one boy with an X-linked inheritance pattern, both SEM and microradiography showed the morphology of the enamel to be unique in the present study. In the other teeth, similar manifestations were found in cases with AI as an AD trait and in the sporadic cases.     

Clinical appearance of dental fluorosis in permanent teeth in relation to histologic changes

Based on studies in Northern Tanzania a new classification system of dental fluorosis is proposed. The classification system includes 10 scores designed to characterize the degree of dental fluorosis affecting buccal/lingual and occlusal surfaces. With aid of polarized and ordinary light microscopy the histologic features behind the individual scores are described. The macroscopic appearance of increasing degrees of dental fluorosis were well correlated to the degree of subsurface porosity. Above a certain level of subsurface hypomineralization various degrees of loss of surface enamel occurred, presumably as a result of posteruptively acquired injuries. Application of the new classification system to samples of children born in areas with 3.5, 6.0 and 21.0 parts/10(6) F- in the water supplies revealed that the distribution of dental fluorosis within the individual followed the same pattern irrespective of fluoride concentration in the water. While the classical Dean index was unable to distinguish between dental fluorosis in the 6.0 and the 21.0 parts/10(6) area it was possible with the new system to disclose that particularly the posterior teeth were significantly more affected in the latter area. Comparisons of degree of dental fluorosis with available measurements of enamel thickness proved that the within-tooth as well as within-dentition variations are determined by enamel thickness rather than length of exposure to body fluids. The limitations of the Dean index are discussed with special attention to its validity as a biological index in relation to current efforts to determine the minimal toxic effect of fluoride on the dental hard tissues.     

Morphological appearance and chemical composition of enamel in primary teeth from patients with 22q11 deletion syndrome

Patients with 22q11 deletion syndrome have many and complex medical problems, including hypocalcemia and/or hypoparathyroidism. Odontological findings include enamel aberrations in both dentitions. In order to describe enamel morphology, chemical composition in primary teeth, and to investigate the relationship between medical history and morphological appearance, dental enamel was investigated in 38 exfoliated primary teeth from 15 children and adolescents. Morphology was studied by the use of a polarized light microscope, microradiography, scanning electron microscopy, X-ray microanalysis, and secondary ion mass spectrometry. The morphological findings were compared with medical history. The teeth showed, in principle, a normal morphological appearance with regard to prism structure. A high frequency of aberrations, such as hypomineralization, hypoplasia and extra incremental lines, were found. The majority of the aberrations were found around the neonatal line. There was a relationship between high numbers of medical problems in the patients and enamel deviations. The result supports the hypothesis of under-reporting of both hypocalcemia and hypoparathyroidism in patients with 22q11 deletion syndrome.     

Microradiographic study of amelogenesis imperfecta

Abstract – A material of 22 primary and 4 permanent teeth from 22 children with amelogenesis imperfecta (AI) were examined by microradiographic techniques. The children were part of a patient material earlier examined in genetical and clinical studies. The results were compared with corresponding data from two non-affected control groups and correlated with the available clinical and genetical data. Teeth were examined from seven of the eight different variants of AI seen in the clinical study. In most cases both hypoplasias and areas of hypomineralization were observed in the same tooth, indicating that both the secretory and the maturation phases of the amelogenesis are affected in AI. In teeth from children with the same clinical variant but different inheritance patterns, no specific finding could be related to a specific inheritance pattern. The findings in the one boy with AI as an X-linked trait were unique in this material. In all control teeth except one, no hypoplasias or areas of hypomineralization were found in the enamel. In conclusion, the subclassification of AI into different forms can be questioned. Variations in clinical and histologic characteristics connected with the same inheritance pattern suggest that the genetic defect, in conjunction with a large biological variation, could explain the multiplicity in clinical expressivity that characterizes AI.     

Prevalence of developmental enamel defects in children with cerebral palsy

Enamel defects observed in primary anterior teeth of 123 children with congenital cerebral palsy (CP) born 1983 through 1985 in four northern California counties were categorized using an adaptation of the Developmental Defects of Enamel Index. Nineteen children (15%) had crowns or loss of tooth substance (LTS) due to attrition. Missing enamel (ME) including horizontal groove, was observed in 39 children (32%). Twenty-four children without ME (20%) had enamel pits, vertical grooves, or colored enamel opacities. Forty-one (33%) had clinically normal enamel. ME children did not differ significantly from those with normal enamel with respect to race, sex, singleton vs twin, severity or type of CP, or presence of dysmorphic features. ME children more often had shorter gestational ages than children with normal enamel. More ME children, even those who were not low in birth weight, were reported by parents to have required neonatal intensive care.     

Amelogenesis imperfecta: prevalence and incidence in a northern Swedish county

Abstract The aim of the study was to establish the prevalence and incidence of amelogenesis imperfecta (AI) in the county of Vasterbotten, northern Sweden using the criteria of Witkop & Sauk (1976). The diagnoses were based upon clinical and radiographic evidence. The study-population consisted of all 3-19-yr-olds born in the county from 1963 to 1979. AI was diagnosed in 79 children, 41 girls and 38 boys, giving a prevalence of 1.4:1000. The mean incidence 1963-79 was 1.3:1000. Half of the children with AI had brothers or sisters in the group. The hypoplastic form was the most common (58 children) followed by the hypomaturation form (16 children). Only five children had the hypomineralization form.     

Posteruptive tooth age and severity of dental fluorosis in Kenya

The purpose of the present study was to assess whether the degree of severity of enamel changes in a population exhibiting rather severe dental fluorosis may be related to posteruptive tooth age and to describe the clinical manifestations of the enamel destructions. All permanent teeth in 102 children aged 10-15 yr who were born and reared in a 2 ppm fluoride area of Kenya were examined for dental fluorosis using the TF-Index. Clinically, at time of eruption all teeth appeared chalky white, but already prior to coming into occlusion discrete pits had formed. A variety of more extensive damages to the surface enamel was found in teeth already in occlusion. In particular, the maxillary incisors exhibited extensive artificial attrition for cosmetic reasons, which make these teeth unreliable for accurate scoring of severity in the present population. An analysis of the proportion of teeth exhibiting TFI-scores 4+, 5+ and 6+ showed that children aged 13-15 yr had a significantly greater proportion of teeth with TFI-scores greater than or equal to 6 compared to children aged 10-12 yr (Wilcoxon, P less than 0.0001). This finding is unlikely to be a result of different fluoride exposures in the two age groups and indicates that even several years after eruption there is a trend towards an increasing severity of enamel surface destructions in children exhibiting pronounced degrees of subsurface enamel hypomineralization at time of eruption.     

Factors associated with molar incisor hypomineralization in Thai children

Molar incisor hypomineralization (MIH) is a qualitative developmental enamel defect that affects one to four permanent first molars, with or without involvement of permanent incisors. Its etiology is of systemic origin, but is not well understood. Therefore, we conducted this cross‐sectional study to examine pre‐, peri‐, and postnatal risk factors for MIH among children, 7–8 yr of age, in urban areas of Khon Kaen, Thailand. Molar incisor hypomineralization defects were diagnosed using the European Academy of Pediatric Dentistry criteria. Mothers or primary caregivers were interviewed on maternal medical history and habits during pregnancy, pregnancy and delivery complications, and the child's medical history. Molar incisor hypomineralization defects were observed in 78 (27.7%) of 282 children. Multiple logistic regression analysis showed a statistically significant association between the development of MIH and Cesarean section (adjusted OR = 2.0, 95% CI = 1.1–3.7), complications during vaginal delivery (adjusted OR = 4.5, 95% CI = 1.9–11.0), and severe/chronic illness when under 3 yr of age (adjusted OR = 2.9, 95% CI = 1.6–5.0). There was no association of preterm birth and low birth weight with MIH. The results suggest that Cesarean section, complications during vaginal delivery, and poor health during the first 3 yr of life are independent risk factors for MIH.     

Preterm infants--odontological aspects

Preterm birth is associated with medical complications and treatments postnatally and disturbances in growth and development. Primary and permanent teeth develop during this postnatal period. The overall aim of the present thesis was to elucidate the effects of preterm birth and postnatal complications on oral health and the dentoalveolar development during adolescence, and to study the effects of preterm birth on caries during childhood, in a well-defined group of preterm infants. In the same group, explore the development of the primary and permanent teeth and compare the results with a matched control group and control teeth. The subjects consisted of 40 (45) of 56 surviving infants, born < 29 weeks of gestational age (GA), and matched healthy children born at term. The material consisted of 44 teeth from 14 of the preterm adolescents and 36 control teeth from healthy children. Clinical examinations and dental cast analysis were performed during adolescence and morbidity was noted. Retrospective information from medical and dental records was obtained. Dental enamel was analyzed in a polarized light microscopy, and scanning electron microscopy. Further, chemical analyses of enamel and dentin were performed with X-ray microanalysis. The results showed that during adolescence, more preterms had plaque and gingival inflammation, lower salivary secretion, more S. mutans and severe hypomineralization. Retrospectively, less caries was noted at six years of age, but more children had hypomineralization in the primary dentition. Angle Class II malocclusion, large over-bite and deep bite associated with medical diagnoses were frequent. Furthermore, smaller dental arch perimeters in girls, at 16 years of age, and smaller tooth size in the incisors, canines and first molars were found. The morphological findings were confirmed in the XRMA analyses. In postnatal enamel, varying degrees of porosities > 5% and incremental lines were seen. Lower values of Ca and Ca/C ratio and higher values of C were found. Ca/P ratio in both enamel and dentine indicates normal hydroxyapatite in both groups. No single medical diagnosis, postnatal treatment or morbidity in adolescents could explain the findings. As a conclusion, there are indications for poor oral outcome in this group of preterm infants during adolescence, and disturbed mineralization in primary teeth.     

Developmental enamel defects in children born preterm: a systematic review

The purpose of this review was to evaluate the association between developmental enamel defects and children born preterm. An identical search was performed in PubMed and Embase and was limited to human studies and studies written in English, German, Danish, Swedish, or Norwegian. Reviews, case studies, and case series were excluded. A total of 283 articles were identified. Twenty‐three publications, of which 19 were follow‐up studies, two were case–control studies, and two were cross‐sectional surveys, were enrolled in the review. The majority of the studies (n = 17) dealt with enamel hypoplasia of the primary teeth. Thirteen studies reported an association between preterm birth and enamel hypoplasia, and, in addition, few studies reported an increased risk of enamel opacities in the primary teeth, in children with a birth weight <1500 g. Seven studies dealt with enamel disturbances of the permanent teeth, four of which suggested an increased risk of enamel opacities. This systematic review suggests an increased risk of enamel hypoplasia in primary teeth of children born preterm and enamel opacities in very‐low birth‐weight children. A larger number of well‐designed studies are, however, needed in order to increase the validity of the studies.     

Caries prevalence and enamel defects in 5- and 10-year-old children with cleft lip and/or palate: A case-control study

Objective. To determine the prevalence of dental caries and enamel defects in 5- and 10-year-old Swedish children with cleft lip and/or palate (CL(P)) in comparison to non-cleft controls. Materials and methods. The study group consisted of 139 children with CL(P) (80 subjects aged 5 years and 59 aged 10 years) and 313 age-matched non-cleft controls. All children were examined by one of two calibrated examiners. Caries was scored according to the International Caries Detection and Assessment System (ICDAS-II) and enamel defects as presence and frequency of hypoplasia and hypomineralization. Results. The caries prevalence among the 5-year-old CL(P) children and the non-cleft controls was 36% and 18%, respectively (p < 0.05). The CL(P) children had higher caries frequency (initial and cavitated lesions) in the primary dentition than their controls (1.2 vs 0.9; p < 0.05). A significantly higher prevalence of enamel defects was found in CL(P) children of both age groups and anterior permanent teeth were most commonly affected. Conclusions. Preschool children with cleft lip and/or palate seem to have more caries in the primary dentition than age-matched non-cleft controls. Enamel defects were more common in CL(P) children in both age groups.     

Nonfluoride hypomineralizations in the permanent first molars and their impact on the treatment need

To determine the prevalence of nonfluoride enamel hypomineralization in the permanent first molars, we examined 488 7- to 13-year-old children. We further examined the impact of such defects on the treatment need by evaluating the number of caries lesions, restorations and extractions of the target teeth. Nonfluoride hypomineralization(s) were seen in 94 children (19.3%). The severity of defects varied from mild lesions with local color change to more severe ones where the hypomineralized tissue had been replaced by a restoration or the tooth had been extracted. Further examination of 65 children with nonfluoride hypomineralization showed that the defects had significantly increased the treatment need of the target teeth compared with the age- and sex-matched controls (p<0.001). Consequently, also the DMFT index of the whole dentition was higher in the children with hypomineralizations than in the controls (p<0.05). The results indicate that nonfluoride hypomineralizations have a significant impact on treatment need in the present child population with low caries activity.     

Excessive fluoride reduces Foxo1 expression in dental epithelial cells of the rat incisor

Enamel fluorosis is characterized by hypomineralization, and forkhead box O1 (Foxo1) is essential for mouse enamel biomineralization. This study investigated the effect of fluoride on Foxo1 expression and its implications for enamel fluorosis. Mandibular incisors were extracted from Sprague Dawley rats treated for 3 months with water containing 0, 50, or 100 p.p.m. F^?. Immunohistochemistry was used to localize and quantify FOXO1 expression in dental epithelial layer cells of the incisors. The effect of fluoride on expression of Foxo1, kallikrein‐4 (Klk4), and amelotin (Amtn) mRNAs was analyzed by real‐time RT‐PCR, and western blotting was used to measure total and nuclear FOXO1 protein levels in mature dental epithelial cells. The results revealed that nuclear FOXO1 was mainly localized in the transition and the mature ameloblasts and exhibited weaker expression in the rats exposed to fluoride. In addition to the reduced levels of Foxo1, Klk4, and AmtnmRNAs, the protein levels of total and nuclearFOXO1 were decreased in the mature dental epithelial cells exposed to fluoride. Thus, excessive fluoride may have an effect on the expression levels of Foxo1 in dental epithelial cells and thereby affect hypomineralization of the enamel during fluorosis.     

Hypoplastic enamel defects and environmental stress in a homogeneous Romano-British population

This study investigated hypoplastic enamel defects in a well-defined sample of Romano-Britons from the 3rd to the 5th century AD and compared the findings with a modern British sample investigated by the same authors. All 178 excavated skulls with intact dentitions were examined for hypoplastic defects using the Federation Dentaire International (FDI) Developmental Defects of Enamel Index criteria. Histopathological and microradiographic sections were prepared of 5 teeth. Hypoplastic defects were found in the teeth of 37% of skulls, with 25% having 4 or more teeth affected. The teeth most frequently involved were canines. Of the defects, 75% were horizontal grooves, 12.7% were pitting, and 7.1% were areas of missing enamel. The location of defects was 82% buccal, 16.5% lingual, and 1.2% occlusal. The reproducibility of diagnosis was 84%. Microscopic and microradiographic investigations showed areas of hypomineralization of enamel and wide zones of interglobular dentine related to the hypoplastic grooves. There was higher frequency, different morphology, and greater severity of hypoplastic enamel defects compared with the modern British sample. The defects may be related to repeated environmental stresses between the ages of 2 and 6 yr. Identified environmental stresses in these Romano-Britons, including high lead ingestion, poor nutrition, and recurrent infections, may be important etiological factors for the enamel defects.     

Dental treatment, dental fear and behaviour management problems in children with severe enamel hypomineralization of their permanent first molars

Summary. Objectives. To assess the demand for restorative treatment, dental anxiety and dental behaviour management problems among children with severe hypomineralization of their first molars (MIH). Design. Case control study. Sample and methods. Data were compiled from the dental records of 32 9‐year‐old children with severe enamel hypomineralization of their first molars and from 41 controls of the same age group concerning dental health, a number of restorative treatments, use of local anaesthesia and clinical behaviour management problems (BMP). A questionnaire containing specific questions on children’s experiences of dental care and the Children’s Fear Survey Schedule – Dental Subscale (CFSS‐DS), was answered by the parents. Results. The children in the study group had undergone dental treatment of their first molars nearly 10 times as often as the children in the control group. Repeated treatments of these teeth at brief intervals were common. The dental treatment was often undertaken without the use of local anaesthesia, and BMP, and dental fear and anxiety (DFA) were more common than in the controls. Conclusions. Children with severe enamel hypomineralization of their first molars had had to undergo a considerable amount of dental treatment. It is reasonable to assume that experiences of pain and discomfort on repeated occasions were related to the occurrence of BMP in patients with MIH. An early treatment planning and prognostication based on increased knowledge of hypomineralized first molars is desirable. Local anaesthesia and other pain‐reducing techniques, e.g. sedation, should be used when treating these teeth. Extraction should be considered in cases of extensive disintegration of the crown, in cases of frequently repeated treatments or when pulpal symptoms are hard to cure.     

Mineral distribution in the enamel of teeth with amelogenesis imperfecta as determined by quantitative microradiography

The aim of the present investigation was to determine the mineral distribution in the enamel of teeth with amelogenesis imperfecta (AI) by quantitative microradiography. A further aim was to correlate the findings to clinical manifestations and inheritance patterns for AI. Included in the study were a total of 29 teeth with AI, 28 primary and one permanent, and seven unaffected teeth, five primary and two permanent. Quantitative microradiography was applied to sagittally ground sections. 70–90 μm, of the teeth. The mineral content of the enamel, expressed as percentage by volume, was lower in most of the teeth with AI than in the unaffected teeth. The largest range for the mineral distribution was found in the enamel of the variants clinically characterized by hypomineralization. These teeth showed a mineral distribution pattern that reflected an extremely low mineral content in the bulk of the enamel. In the AI teeth clinically characterized by hypoplasia, the mineral distribution pattern was similar to that of the unaffected teeth, although with larger local variations in mineral content. Apart from the teeth connected with X-linked inheritance, no differences were found among teeth with similar clinical variants connected with different inheritance patterns.