Presence Of Enamel Hypoplasia Research Articles

Analysis of enamel defects in a cave bear maxillary molar, with remarks on incremental markings in bear enamel

AbstractThe paper discusses the formation of an enamel defect in the crown of a cave bear (Ursus spelaeus sensu lato) left maxillary second molar (M2), based on macroscopic and microscopic analysis. The tooth belongs to a cranium recovered from the Cerovac caves in Croatia that exhibits a partially healed, depressed lesion in the left squama frontalis and a further lesion in the left maxilla associated with loss of the M1. Microscopic inspection demonstrated an accentuated incremental line in both enamel and dentin of the left M2. It is suggested that in the defect area the outer enamel had been posteruptively lost along the accentuated line in the enamel that constituted a zone of reduced mechanical resistance. Presence of enamel hypoplasia in both M2 indicated that these developmental lesions reflect a systemic stress event during crown formation of the teeth. The underlying cause of this stress is assumed to have been a trauma to the skull that caused the lesion in the left squama frontalis. It is further suggested that a later trauma to the left maxilla had led to the loss of the left M1 and the flaking‐off of enamel along the accentuated incremental line in the left M2. The defect in the left M2 is thus diagnosed as the result of a developmental lesion during crown formation, related to systemic stress due to a skull trauma, followed by posteruptive damage from a second traumatic impact. In addition to reconstructing the formation of the defect in the crown of the left M2, the paper, for the first time, describes daily and subdaily incremental markings in ursid enamel and provides preliminary information on enamel secretion rate in a cave bear molar.

Prevalence and Cause of Enamel Hypoplasia in Primary Teeth among 1-year-old Japanese Children

Objective: In this study, the prevalence and underlying cause of enamel hypoplasia in one-year-old children were examined. Additionally, to determine the association between enamel hypoplasia and exposure to sunlight based on the frequency of the mother’s outings during pregnancy. Methods: A total of 273 kids (139 boys) were involved in this study. Based on questionnaires surveys to mothers, oral examinations, and photographs of children's mouths, we looked at the connection between the circumstances of pregnancy and the occurrence of enamel hypoplasia. The presence of enamel hypoplasia was assessed using logistic regression analysis differed among the results of the questionnaire. Results: The prevalence of enamel hypoplasia was 38.5%. In the medium and low groups, enamel hypoplasia was more common than in the high group at the birth month of the child (adjusted odds ratio: 3.36, 95% confidence interval: 1.65–6.85, p = 0.001 vs. adjusted odds ratio: 3.76, 95% confidence interval: 1.89–7.48, p < 0.001, respectively). Enamel hypoplasia was knowingly higher among the children whose mothers went out less than 1–2 times a week during pregnancy (adjusted odds ratio: 2.41, 95% confidence interval: 1.04–5.61, p = 0.041). Enamel hypoplasia was significantly more prevalent when mothers used painkillers during pregnancy (adjusted odds ratio: 5.45, 95% Confidence interval: 1.74–17.08, p = 0.004). Conclusion: It was suggested that the use of antipyretic analgesics during pregnancy and frequency of outings and variations in sunshine hours according to the child's birth month could affect the occurrence of enamel hypoplasia.

Enamel Hypoplasia as a Marker for Sex Estimation: A Review

Abstract: Changes in enamel during teeth development are permanently recorded, and some, like enamel hypoplasia (EH), can be linked with stressful events. As males and females may respond differently to stress, EH may have a different prevalence between the sexes. The present work mainly aims to identify which factors may lead to the different EH types, analyse how they manifest between sexes, and check if, in the presence of EH, one can infer about a person’s sex. Our results point to occasional differences in EH prevalence in deciduous dentition between sexes, with males displaying more EH. As for permanent dentition, EH prevalence appears to be strongly associated with the living conditions, namely nutrition, occluding any possible sex bias. Therefore, EH in deciduous teeth can be useful for sex estimation; yet, in permanent dentition, other factors may be responsible for the differences and more studies, with control of environmental factors (for example, twin studies) are needed to understand if sex differences exist as well.

Association Between Molar-Incisor Hypomineralization and Enamel Hypoplasia.

To investigate the association between molar-incisor hypomineralization (MIH) and enamel hypoplasia. The sample consisted of 311 orthodontic files of patients aged between 12 and 18 years, divided into two groups: patients with MIH (109) and without MIH (202). MIH and enamel hypoplasia were diagnosed via panoramic radiographs and intraoral photographs, followed by clinical examination of the MIH-affected patients as per the modified EAPD scoring criteria. Chi-square test and t test were used to assess intergroup comparisons regarding sex, age and race. Fisher's Exact test was used to compare the groups regarding the presence of enamel hypoplasia and the Adjusted Odds Ratios (OR) were calculated. There was an association between MIH and enamel hypoplasia. The prevalence of enamel hypoplasia (5.5%) was significantly higher in patients with MIH compared to the control group (0.49%). MIH lesions increase 12.45-fold the risk of having enamel hypoplasia. Patients with MIH have a higher prevalence of enamel hypoplasia and these defects seem to share the same etiological factor.

Evaluation of the risk factors of dental caries in children with very low birth weight and normal birth weight

BackgroundHealth problems of premature infants can affect both general and oral health. The enamel defects, poor dietary and oral hygiene habits may predispose these children to dental caries. This study was conducted to assess the impact of very low birth weight and prematurity on caries risk in early childhood.MethodsThe study cohort consists of 189 of one year old infants. Anamnestic data were obtained from hospital records, feeding practice, bed-time sugar drinks and oral hygiene onset from questionnaires. Saliva samples of children and their mothers were collected for the detection of cariogenic pathogens.ResultsVLBW newborns had significantly shorter gestation age (29.6 vs. 38.8)) and lower mean birthweight (1124 g vs 3315 g) compared to NBW ones (p < 0.0001). Statistical significance has been found in the presence of early morbidity (p < 0.0001) and regular medication intake (p = 0.007). VLBW children got more frequently sweetened drinks during the day and night (p = 0.007). Regular oral hygiene practice was more frequent in full term group (p = 0.002). There was statistical difference in the presence of enamel hypoplasia in VLBW children (p = 0.033) but no statistical difference in the presence of hypomineralization (p = 0.0736) in comparison to NBW individuals. Proportional representation and count of S. mutans did not reveal statistical difference neither in both groups of children (p = 0.484) nor in both groups of mothers (p = 0.385).ConclusionsThe study confirmed anamnestic and medical differences between both groups. The proportional representation and count of S. mutans did not reveal statistical difference neither in VLBW and NBW children, nor in their mothers.

Influence of physiological stress on the presence of hypoplasia and fluctuating asymmetry in a medieval population from the village of Sypniewo

This study aims to estimate the levels of physiological stress in the medieval rural population of Sypniewo by evaluating patterns of fluctuating asymmetry (FA) and enamel hypoplasia (EH), and provide information on the influence of physiological stress during the prenatal and perinatal period on early childhood development.Stress is defined as any external or internal condition that challenges homeostasis of an organism. FA is associated with physiological stress occurring mainly during prenatal development and early childhood. The level of FA is thought to reflect the intensity of the stressor(s). EH is caused by physiological stress such as nutritional instability during the first years of life.The studied material consisted of 126 skulls from the village of Sypniewo (Poland). Cranial radiographs were taken in postero-anterior (P-A) and basal views. The images were scanned and calibrated. Measurements of the cranium were used to estimate FA. The presence of EH was assessed using standard anthropological methods The highest levels of FA were observed in the region of the cranial base. EH was observed in 29% of individuals from the rural skeletal series. There was no statistically significant correlation between FA and EH occurrence or between sex and the studied stress indicators.

Association between enamel hypoplasia and dental caries in primary second molars and permanent first molars: A 3-year follow-up study

Context: Enamel hypoplasia is a defect caused by disturbances during enamel formation. These defects in the enamel present important clinical significance as they predispose a tooth to dental caries. Aim: The aim of this study was to assess the longitudinal relationships between enamel hypoplasia and caries experience of primary second molars and permanent first molars. Materials and Methods: The study sample consisted of 765 subjects who underwent dental examinations at both ages 6 and 9 by the calibrated examiner. Primary second molars and permanent first molars were scored for the presence of enamel hypoplasia for each participant. Caries presence and number of decayed and filled surfaces (dfs and DFS) were determined at ages 6 and 9. The relationships between enamel hypoplasia and caries experience were assessed using multivariable regression models. Results: At the tooth level, 2.8% and 3.5% of children had hypoplasia on primary second molars and permanent first molars respectively. Multivariable logistic regression analyses showed that children with enamel hypoplasia were at a significantly higher risk of caries at both ages 6 (odds ratio, OR = 5.27 for primary second molars and OR = 3.21 for permanent first molars) and age 9 (OR = 3.45 for primary second molars and OR = 4.57 for permanent first molars), and that a statistically significant association was seen with caries incidence (OR = 2.08 for primary second molars and OR = 2.87 for permanent first molars). Conclusion: Enamel hypoplasia appears to be a significant risk factor for caries in both primary second molars and permanent first molars and should be considered in caries risk assessment.

Dental treatment in children with dystrophic form of epidermolysis bullosa

The aim of the study was to summarize the experience for providing oral health care in children with epidermolysis bullosa (EB) treated in Central Research Institute of Dentistry and Maxillofacial Surgery in 2013-2014. Seven EB patients (5 female and 2 male aged 5-17) with dystrophic form of EB were included in the study. Oral status was recorded (oral hygiene, presence of enamel hypoplasia and intraoral soft tissue lesions). Dental treatment provided included teeth extractions under conscious sedation (6 cases), teeth treatment (both conventional and ART methods) (5 cases) and preventive program (5 cases). All 7 dystrophic EB patients presented with generalized enamel hypoplasia in both primary and permanent dentition. In these patients one should consider using non-adhesive face dressings and careful suction pipe positioning as well as applying liniments on cotton rolls not to cause both intraoral and extraoral soft tissue lesions. Sixteen milk teeth were extracted under conscious sedation, in 3 cases the procedure caused significant vestibular scarring. Twelve teeth were treated mostly by ART method (n=1 0) as limited mouth opening made conventional treatment impossible. Dental treatment in dystrophic EB is a real challenge for pediatric dentist. This group of patients requires a special dental rehabilitation plan as they present with generalized enamel hypoplasia and have significant risk of intraoral lesions.

Impact of low birthweight on early childhood caries in 6–36 months old infants in Uganda: A cross-sectional study

Objective. Focusing on 6–36 months old infants, this study assessed (1) whether socio-economic status, current anthropometric status, presence of enamel hypoplasia, number of erupted teeth, oral hygiene and consumption of sugared snacks varied between children with normal birthweight (NBW) and low birthweight (LBW) and (2) the association between ECC and birthweight whilst adjusting for covariates of ECC, such as current anthropometric status. Method: A cross-sectional study was conducted in Kampala in 2007, involving 816 child/caretaker pairs. All caretakers completed face-to-face interviews. Children were examined for ECC and enamel defects using WHO (1997) criteria and the developmental defects of enamel (DDE) index. Weight at birth was obtained from hospital records and current anthropometric status was assessed using z-scores for weight-for-length (WLZ), length-for-age (LAZ) and weight-for-age (WAZ). Results. Prevalence of LBW (< 2500 g) and ECC were estimated to 11.5% and 18.1%, respectively. Children with LBW and those with ECC presented with more visible plaque, higher sugar consumption and more current underweight (WAZ < −2) than children with normal birth weight (NBW) and no caries; 26.7% of LBW vs 17.3% (p < 0.001) of NBW children presented with ECC. Enamel defects (OR = 2.8, 95% CI = 1.6–4.8) and presence of visible plaque (OR = 2.4, 95% CI = 1.3–4.1), but not LBW, were associated with ECC in multiple variable logistic regression analyses. Conclusion. Both LBW and ECC were associated with poor oral hygiene, high intake of sugars and current underweight. Enamel defects were associated with ECC. Adjusting for covariates there were no clear association between LBW and ECC. Studies using a prospective study design are needed for further investigation.

Enamel hypoplasia in the primary dentition of monozygotic and dizygotic twins compared with singleton controls

The study of enamel hypoplasia (EH) and opacity in twins provides insights into the contribution of genetic and environmental factors in the expression of enamel defects. This study examined prevalence and site concordance of EH and opacity in the primary dentition of 2- to 4-year-old twins and singleton controls to assess the relative contribution of genetics and the environment to the aetiology of these defects. The study sample consisted of 88 twin children and 40 singletons aged 2-4 years of age. Medical histories were obtained and the children examined for enamel defects. The prevalence of EH by teeth was 21% in monozygotic twins (MZ), 22% in dizygotic twins (DZ), and 15% in singleton controls. Twins showed a higher prevalence of EH compared with singletons (P < 0.05). Factors contributing to increase EH in twins were neonatal complications including intubation. There were no significant differences in site concordance of EH within the MZ twin pairs compared with DZ twin pairs when only presence of EH was considered, whereas a greater concordance was noted between MZ twin pairs compared with DZ twin pairs when both presence and absence of EH were considered. The results suggest that both genetic and environmental factors contribute to observed variation of EH, although it is likely that environmental factors exert a greater influence.

Type XVII Collagen is a Key Player in Tooth Enamel Formation

Inherited tooth enamel hypoplasia occurs due to mutations in genes that encode major enamel components. Enamel hypoplasia also has been reported in junctional epidermolysis bullosa, caused by mutations in the genes that encode type XVII collagen (COL17), a component of the epithelial-mesenchymal junction. To elucidate the pathological mechanisms of the enamel hypoplasia that arise from the deficiency of epithelial-mesenchymal junction molecules, such as COL17, we investigated tooth formation in our recently established Col17(-/-) and Col17 rescued mice. Compared with wild-type mice, the incisors of the Col17(-/-) mice exhibited reduced yellow pigmentation, diminished iron deposition, delayed calcification, and markedly irregular enamel prisms, indicating the presence of enamel hypoplasia. The molars of the Col17(-/-) mice demonstrated advanced occlusal wear. These abnormalities were corrected in the Col17 rescued humanized mice. Thus, the Col17(-/-) mice clearly reproduced the enamel hypoplasia in human patients with junctional epidermolysis bullosa. We were able to investigate tooth formation in the Col17(-/-) mice because the Col17(-/-) genotype is not lethal. Col17(-/-) mouse incisors had poorly differentiated ameloblasts that lacked enamel protein-secreting Tomes' processes and reduced mRNA expression of amelogenin, ameloblastin, and of other enamel genes. These findings indicated that COL17 regulates ameloblast differentiation and is essential for normal formation of Tomes' processes. In conclusion, COL17 deficiency disrupts the epithelial-mesenchymal interactions, leading to both defective ameloblast differentiation and enamel malformation.

Problems and pitfalls in the diagnosis of linear enamel hypoplasia in cheek teeth of cattle

Prevalence and intensity of enamel hypoplasia have been used as markers of generalized physiological stress during dental development in a wide range of mammalian taxa. We studied cattle ( Bos taurus) cheek teeth exhibiting morphological characteristics that are of relevance to the diagnosis of enamel hypoplasia in this and other bovid species. These characteristics were multiple, more or less horizontally arranged (waveform) lines or grooves in the cementum of the tooth crown and the adjacent root area, leading to an imbricated appearance of the cementum. On macroscopic examination of tooth surfaces, these lines resembled linear enamel hypoplasia (LEH). Microscopic analysis of tooth sections, however, revealed that the lines occurred in the cementum only, and that the underlying enamel did not exhibit morphological irregularities. In cheek teeth of older cattle, a thick cementum layer is regularly found in the cervical crown portion and the adjacent root area. Apposition of this cementum is related to the uplifting of the teeth from their alveoli, a process that compensates for the shortening of the tooth crowns due to occlusal wear. In the studied specimens, a pronounced periodic nature of tooth uplifting and the related deposition of cementum is the likely cause for the observed imbricated appearance of the cementum. While this phenomenon may be misinterpreted as representing a case of LEH, presence of enamel hypoplasia in bovid teeth may be overlooked when the defects become filled with coronal cementum and are therefore not apparent on external inspection. This was the case in one of the cattle teeth analyzed by us, in which the hypoplastic enamel defects were, however, clearly discernible in ground sections. Microscopic analysis of tooth sections is recommended for recording of LEH in bovid teeth in cases where macroscopic examination of tooth surfaces alone does not produce unequivocal results.

Environmental stress in the Early Mediaeval Slavic population at Borovce (Slovakia)

Several palaeopathological indicators examined in skeletal samples are caused by stress during childhood and remain visible in adults. In this study, dental enamel hypoplasia was observed in 451 individuals from the Early Mediaeval (8th to beginning of 12th c. AD) Slavic skeletal series at Borovce (Slovakia). The presence of enamel hypoplasia was scored in all types of deciduous and permanent teeth. More than one-fourth (27.2%) of the individuals with preserved permanent teeth showed enamel hypoplasia. No significant differences in the occurrence of the enamel lesions were found between males and females. The age at development of hypoplasias was estimated for 74 individuals by measuring the distance of the defect from the cemento-enamel junction. The hypoplastic defects appeared most frequently between 2.5 and 3.0 years. Following the trends observed in the distribution of age at development of the enamel lesions between subadults and adults, individuals stressed earlier in life had a reduced ability to cope with later insults. High prevalence of enamel hypoplasia, especially among 10–14-year-old growing juveniles, has led to the assumption that the Borovce population lived a considerably long period under conditions of high environmental pathogen load, and probably also suffered from some nutritional deficiencies.

SEM Study of the Development of Rat Incisor Enamel Hypoplasia Under Hypocalcemia Induced by Thyro-Parathyroidectomy

Several clinical studies have reported the presence of enamel hypoplasia in congenital hypoparathyroidism or hypocalcemia. In previous studies we showed that thyro-parathyroidectomy (TPTX) induced perturbations of the ameloblast morphology and secretion, of the rod pattern and of the enamel surface at late secretory stage and beginning of maturation, and limited hypoplasia in the erupted enamel of rat incisor. The aim of the present study was to evaluate by SEM, the extent and evolution of the enamel alterations of thyro-parathyroidectomized rats during the maturation stage. Wistar rats were thyro-parathyroidectomized and sacrificed 57 days later. The incisors were dissected out and processed for SEM. The surface of the incisor was observed from the end of secretion/beginning of maturation to its incisal erupted end. Transverse sections were prepared to study the structural defects and the prism pattern at different stages. The results showed that the surface of the TPTX incisors presented large hypoplastic defects at the end of secretion/beginning of maturation and only small defects in the erupted part. Transverse sections showed that, at the transition from secretion to maturation, the enamel defects extended to the mid-thickness of the tissue. At the incisal end the defects were limited to the outer enamel. As it is difficult to understand how the large apical defects could recover to appear as small hypoplasia at the incisal end, these results raise new questions concerning: (1) the effect of a long term calcium deficiency upon the cellular activity of the ameloblasts, and (2) the capacity of the enamel organ to compensate structural abnormalities.

Caries experience in deciduous dentition of rural Chinese children 3-5 years old in relation to the presence or absence of enamel hypoplasia.

The association of enamel hypoplasia (EHP) with dental caries of the deciduous dentition was determined in 1,344 rural Chinese children aged 3-5 years. The degree of EHP was determined using a modified DDE Index. Number of decayed, missing, and filled teeth and tooth surfaces were determined for all subjects. Anthropometric assessment of body weight and height was done as an indirect measure of the nutritional status of the children. Results from the study showed that the prevalence of EHP was 22.3% in the total study population. The prevalence of dental caries was 82.3%. There was no difference in the caries experience between males and females. Significantly greater caries experience was observed among the children living in a low socioeconomic county and children with low height for age. Children with low birth weight showed a slightly higher percentage of caries than those born with normal birth weight. Children with enamel hypoplasia demonstrated a significantly higher caries experience than those who did not have such defects. The results of this study consistently support previous studies that found nutritional deficiency to have an important impact on tooth development and susceptibility to dental diseases. This study also indicates that the presence of enamel hypoplasia may be a predisposing factor for initiation and progression of dental caries, and a predictor of high caries susceptibility in a community, particularly if fluoride programs are not implemented.

Colonization by mutans streptococci in the mouths of 3- and 4-year-old Chinese children with or without enamel hypoplasia

This case-control study compared the prevalence and concentration of mutans streptococci (MS) in saliva between children with and without enamel hypoplasia (EHP). A total of 486 3- or 4-year-old Chinese children were initially screened for EHP, then distributed into two groups: 234 children diagnosed as having EHP were assigned to the case group; 252 who were free of EHP were included in the control group. The concentration of MS in saliva was assayed for each child. Nutritional status was deduced from body height and weight. Birth weight, prematurity, and nursing history were also determined. MS were found in 94.7% of the study population. The differences in MS concentrations were not associated with low birth weight, prematurity, length of breast feeding, or body height and weight. A statistically significant association existed between the presence of EHP and high counts of MS ( p < 0.001). High MS counts were correlated with severity of enamel defects ( p < 0.001). When the caries status of the children was controlled as the confounding factor in statistical analyses, the association between EHP and MS decreased but still remained significant ( p = 0.025). This study shows that high MS counts are correlated with EHP, suggesting that irregularities in enamel surfaces could be a contributing factor that fosters the increased colonization of MS in the mouths of children.