Children Of Chronological Age Research Articles

Impact of maternal cardiometabolic status after bariatric surgery on the association between telomere length and adiposity in offspring

The impact of bariatric surgery on metabolic and inflammatory status are reflected in the epigenetic profile and telomere length mediated by the changes in the metabolic status of the patients. This study compared the telomere length of children born before versus after maternal bariatric surgery as a surrogate to test the influence of the mother’s metabolic status on children’s telomere length. DNA methylation telomere length (DNAmTL) was estimated from Methylation-EPIC BeadChip array data from a total of 24 children born before and after maternal bariatric surgery in the greater Quebec City area. DNAmTL was inversely associated with chronological age in children (r = − 0.80, p < 0.001) and significant differences were observed on age-adjusted DNAmTL between children born before versus after the maternal bariatric surgery. The associations found between body mass index and body fat percentage with DNAmTL in children born after the surgery were influenced by maternal triglycerides, TG/HDL-C ratio and TyG index. This study reports the impact of maternal bariatric surgery on offspring telomere length. The influence of maternal metabolic status on the association between telomere length and markers of adiposity in children suggests a putative modulating effect of bariatric surgery on the cardiometabolic risk in offspring.

Impact of Age on Reading Abilities in Egyptian Children with Unilateral Cochlear Implant

Abstract Background Reading problems means difficulty in learning to read or interpret words, letters, and other symbols. Children with cochlear implants generally suffer from reading problems which have been partly attributed to underlying deficit in phonological awareness. Chronological age represents important factor that affects their reading abilities. Aim of the Work This work aims to assess reading abilities in cochlear implant school children in order to highlight their reading problem profile, as to consider such problems in earlier years of life. This would subsequently solve their expected academic delay. Subjects and Methods This study was applied on 30 Egyptian Arabic-speaking children with unilateral cochlear implant in the age range between 5 to 11 years old. All of them underwent audiological evaluation, psychometric evaluation, Phonological Awareness Test, and Arabic Reading Screening Test (ARST). Results Analysis of the results of the participated children to the phonological awareness test and Arabic reading screening test, revealed that the majority of the studied patients were below the 5th percentile in all sub items of both tests. This indicates that cochlear implanted children have reading problems. There is positive correlation between most of subitems of both tests and chronological age of children. Conclusion and recommendation Cochlear implanted children had poor scores in phonological awareness test and Arabic reading screening test, their reading abilities were extremely impaired. Chronological age may be considered a factor that affects this relation. This higher susceptibility to reading problems as well as the importance of reading for their academic careers should be considered in their rehabilitation plan.

Stability selection enhances feature selection and enables accurate prediction of gestational age using only five DNA methylation sites

BackgroundDNA methylation (DNAm) is robustly associated with chronological age in children and adults, and gestational age (GA) in newborns. This property has enabled the development of several epigenetic clocks that can accurately predict chronological age and GA. However, the lack of overlap in predictive CpGs across different epigenetic clocks remains elusive. Our main aim was therefore to identify and characterize CpGs that are stably predictive of GA.ResultsWe applied a statistical approach called ‘stability selection’ to DNAm data from 2138 newborns in the Norwegian Mother, Father, and Child Cohort study. Stability selection combines subsampling with variable selection to restrict the number of false discoveries in the set of selected variables. Twenty-four CpGs were identified as being stably predictive of GA. Intriguingly, only up to 10% of the CpGs in previous GA clocks were found to be stably selected. Based on these results, we used generalized additive model regression to develop a new GA clock consisting of only five CpGs, which showed a similar predictive performance as previous GA clocks (R2 = 0.674, median absolute deviation = 4.4 days). These CpGs were in or near genes and regulatory regions involved in immune responses, metabolism, and developmental processes. Furthermore, accounting for nonlinear associations improved prediction performance in preterm newborns.ConclusionWe present a methodological framework for feature selection that is broadly applicable to any trait that can be predicted from DNAm data. We demonstrate its utility by identifying CpGs that are highly predictive of GA and present a new and highly performant GA clock based on only five CpGs that is more amenable to a clinical setting.

Reliability of mathematical regression models for age estimation in the mixed dentition stage for Egyptian children

BackgroundThe purpose of this study was to evaluate the accuracy of established mathematical regression models for estimating the age of Egyptian children, develop new models that would better match this population and to evaluate the validity and reliability of these new models.ResultsOne thousand one hundred fifteen children ranging in age between 6–14 years participated in the study. Group I consisted of 1000 children; 513 (51.3%) children were of the age group 6–< 9 years and 487 (48.7%) children were 9–14 years. Male children were 484 (48.4%) while female children were 516 (51.6%). Group II consisted of 115 children; 84 (73%) children were of the age group 6–< 9 years and 31 (27%) children were 9–14 years. Male children were 58 (50.4%) while Female children were 57 (49.6%). Foti regression models showed poor agreement of Intraclass Correlation Coefficient (ICC) with chronological age of children in the mixed dentition stage. The new regression models for estimating dental age showed ICC of more than 0.7 with chronological age suggesting better accuracy in age estimation than Foti models.ConclusionsThe newly formulated regression models are reliable for estimating the age of Egyptian children during the mixed dentition stage. A good agreement was found between the estimated age obtained from the first two models and the chronological age. However, the third model had the least agreement, suggesting that age estimation may be more accurate using only the first two models.

Estimation of dental age in children in a Turkish population with tooth agenesis

Aim: The aim of this study was to investigate tooth development according to chronological age in children with tooth agenesis and to determine whether the severity of tooth agenesis (hypodontia and oligodontia) has an effect on tooth development. Methods: In this retrospective study, the records of children diagnosed with hypodontia and oligodontia referred to the Department of Pediatric Dentistry between January 1, 1999 and January 1, 2018 were examined. The control group was matched with children diagnosed with oligodontia and hypodontia in terms of age and gender. A total of 288 children aged between 6-15 years were included in the study and the control, hypodontic and oligodontic groups were formed as Group I, Group II and Group III, respectively. Chronologic age was calculated and Haavikko's method was used for dental age. The difference between chronological and dental ages was analyzed by ANOVA test and Tukey test was used for multiple comparisons. Results: There was a difference was determined between groups I and III in dental age determined by Haavikko’s method (p&lt;0.05). When the difference between chronological age and dental age determined, it was found that in Group I, II, III, dental age was 0.71, 1.17, 1.88 years behind respectively chronological-age and this difference was statistically significant (p&lt;0.05). Conclusions: In this study, delayed tooth development was observed in children with oligodontia compared to children without tooth agenesis. Keywords: Age Determination by Teeth; Forensic Dentistry; Tooth Agenesis Selective

Accuracy of Demirjian's and Cameriere's Methods for Age Estimation in 6- to 10-Year-Old Iranian Children Using Panoramic Radiographs.

Objective This study assessed the accuracy of Demirjian's and Cameriere's methods for age estimation in Iranian children using panoramic radiographs. Materials and Methods This cross-sectional study evaluated 212 panoramic radiographs of 6- to 10-year-old children retrieved from the archives of an oral and maxillofacial radiology department from 2011 to 2017. The chronological age of children at the time of radiography was determined by subtracting the date of radiography from their birth date. The developmental stage of 7 permanent left mandibular teeth was determined according to Demirjian's method. The stage of dental maturation was determined according to Cameriere's method by using the normalized values for 7 permanent left mandibular teeth and the number of teeth with complete root development. The error value of the two methods was calculated by comparing them with the actual chronological age of male and female children, and the absolute error values of the two methods were compared with paired t-tests. Results The mean error value of Demirjian's and Cameriere's methods was found to be 0.84 and −0.06 in girls and 0.93 and 0.04 in boys, respectively. Significant differences were noted in the absolute error of the two methods compared with the chronological age of male and female children (both Ps < 0.001). Conclusion In conclusion, this study indicated that Cameriere's method was more accurate than Demirjian's method for age estimation in Iranian children.

EVALUATION OF THE DENTAL AGE ESTIMATION ON DIGITAL PANORAMIC RADIOGRAPHIES

<h3>Objectives</h3> To investigate the relationship between the chronology of dental age and the chronological age of children from panoramic radiographs. <h3>Study Design</h3> This was a cross-sectional and observational study. The study consisted of 20 digital panoramic radiographic images dated from the 2018, obeying the following criteria: patient age and panoramic radiographs with good image quality. We then obtained access to patients' files to obtain their chronological age. The data were divided by sex and analyzed statistically through the variance of 2 factors (chronological and dental age). <h3>Results</h3> When analyzing female patients, there was an advance in dental age up to 2 years from the chronological age. In male patients, there was a greater similarity between ages. During the analysis, similarity was found in the parity of the arcs, showing bilateral symmetry. <h3>Conclusions</h3> The result showed a high correlation between dental age and chronological age in male patients. This condition is useful to monitor dental-facial health in sync with postnatal growth and development. No significant differences were observed between arches during the eruption of permanent teeth.

Comparative assessment of Demerijian\'s and Cameriere\'s dental age estimation in children - A panaromic radiographic study

Age estimation in children is a fundamental question in forensic medicine and in treatment planning. Estimation of age is required to answer a variety of legal questions like status of majority and criminal liability such as in child marriage, sexual harassment and in situations where birth data is lacking or doubted.Various methods have been proposed for assessment of the dental maturation, but the most widely applied method is by Demirijian et al. Cameriere’s method is also used to assess chronological age in children with open apex. With this background, the present study was conducted to estimate the dental age of the children from open and closed apex.240 digital panoramic radiograph of patients aged between 5 and 15 years were taken randomly Dental age estimation was performed using by Demirijians and Cameriere‘s method.The mean difference between the chronological and dental age was found to be 3.93 and 0.17 for Demirijian’s and Cameriere’s age estimation method respectively. In Demirijian’s method, the accuracy was found more in older females where as in Cameriere’s method the accuracy was almost same in all the age groups and the precision was seen in males than in females, on comparison Cameriere’s age estimation method was more accurate than Demirijian’s method.Dental maturity can be used to assess chronological age in children either by Demirijian’s or Cameriere’s method, Cameriere’s method was more accurate than Demirijian’s method.

Does the crypt: tooth ratio in the developing tooth correlate with chronological age in children?—a novel, radiographic, cross-sectional pilot study using ImageJ tools

BackgroundThe bony cavity known as the crypt encloses the developing tooth, the size of which is influenced by the tooth movements during various phases of tooth eruption. The radiographic observations have revealed that the size of the crypt decreases as the root formation continues. The present study was conducted to assess the relationship between the crypt to tooth ratio (CTR) and the chronological age in children in the age range of 4 to 16 years using their digital panoramic radiographs (OPGs). The ImageJ tools were used to calculate the area of the bony crypt and the area of the developing mandibular second molar from 145 OPGs. The ratio between the area of the crypt and the area of the calcified portion of the tooth was obtained and compared with the calendric age (CA) to develop a regression model for age estimation.ResultsThere was a significant negative correlation between the chronological age and the CTR values (r= −0.898, p<0.001) in all the age groups. The derived regression formula was age = 17.192–3.855 (CTR) with an r2 value of 0.807 and a standard error of estimate (SEE) being 1.385. The derived formula was tested using 52 OPGs from a different set of patients in the same age group. The mean chronological age of the test sample was 9.57 years (± 3.42), their mean estimated age (EA) was 8.50 years (± 3.25), and the difference was statistically significant (p<0.001). A difference of more than 1 year was observed in 69% of boys and 54% of girls.ConclusionsThis method is an attempt to correlate the crypt to tooth ratio of developing the second molar tooth with the chronological age. A large sample study is required to validate this novel technique of age estimation in children.

Robust Estimation of the Chronological Age of Children and Adolescents Using Tooth Geometry Indicators and POD-GP.

Determining the chronological age of children or adolescents is becoming an extremely necessary and important issue. Correct age-assessment methods are especially important in the process of international adoption and in the case of immigrants without valid documents confirming their identity. It is well known that traditional, analog methods widely used in clinical evaluation are burdened with a high error rate and are characterized by low accuracy. On the other hand, new digital approaches appear in medicine more and more often, which allow the increase of the accuracy of these estimates, and thus equip doctors with a tool for reliable estimation of the chronological age of children and adolescents. In this study, the work on a fast and effective metamodel is continued. Metamodels have one great advantage over all other analog and quasidigital methods—if they are well trained, a priori, on a representative set of samples, then in the age-assessment phase, results are obtained in a fraction of a second and with little error (reduced to months). In the here-proposed method, the standard deviation for each estimate is additionally obtained, which allows the assessment of the certainty of each result. In this study, 619 pantomographic photos of 619 patients (296 girls and 323 boys) of different ages were used. In the numerical procedure, on the other hand, a metamodel based on the Proper Orthogonal Decomposition (POD) and Gaussian processes (GP) were utilized. The accuracy of the trained model was up to 95%.

Radiological and nonradiological methods of dental and skeletal age assessment: A narrative review

Age is one of the essential factors which play an important role in every aspect of life. Importance of age determination is related to many fields including treatment planning and drug delivery in pediatric dentistry, orthodontics, forensic sciences, and also in individuals who provide inaccurate details of age as in cases of illegal immigrants and in the corpse of unknown identity. The age estimation methods at different stages of life consist of a physical examination, radiographic examination of the hand bones and cervical vertebrae, and dental examination using two-dimensional and three-dimensional imaging. The different dental age estimation methods used are morphological, biochemical, and radiological methods. These methods have inborn advantages and disadvantages. Other than dental age, skeletal age has also been used to determine a child's development as skeletal maturity is closely related to the craniofacial growth. Correlation of the dental and skeletal ages with the chronological age of children helps clinicians to estimate the growth left in the child and the possible treatment that can be carried out utilizing it. This article critically reviews various dental and skeletal aspects of age estimation from infancy to adulthood with its scope and limitation.

Frequency-Dependent Changes in Interhemispheric Functional Connectivity Measured by Resting-State fMRI in Children With Idiopathic Generalized Epilepsy.

Epilepsy is associated with abnormal spatiotemporal changes in resting-state brain connectivity, but how these changes are characterized in interhemispheric coupling remains unclear. This study aimed to characterize frequency-dependent alterations in voxel-wise mirrored homotopic connectivity (VMHC) measured by resting-state functional magnetic resonance imaging (rs-fMRI) in children with idiopathic generalized epilepsy (IGE). Rs-fMRI data were collected in 21 children with IGE and 22 demographically matched children with typical development. We used three resting-state frequency bands (full, 0.01–0.08 Hz; slow-4, 0.027–0.073 Hz; slow-5, 0.01–0.027 Hz) to compute VMHC and locate the significant foci. Voxel-wise p <0.001 and cluster-level p <0.05 cluster-level family-wise error correction was applied. In between-group comparisons, we identified that the full and higher frequency (slow-4) bands showed similar reductions in VMHC including Rolandic operculum, putamen, superior frontal, lateral parietal, middle cingulate, and precuneus in children with IGE. In the lower frequency band (slow-5), we identified specific reductions in VMHC in orbitofrontal and middle temporal gyri in children with IGE. Further analyses on main effects and interaction between group and frequency band suggested significant frequency-dependent changes in VMHC, and no significant interaction was found. The results were generally similar with global brain signal regression. Additional association analysis showed that VMHC in the putamen within the full and slow-4 bands was significantly positively correlated with chronological age in children with IGE, and the same analysis was non-significant in the controls; VMHC in the medial prefrontal region in the slow-4 band was significantly positively correlated with IQ performance sub-score. Our findings suggest that IGE children show frequency-dependent changes in interhemispheric integration that spans regions and systems involving cortical-subcortical, language, and visuomotor processing. Decreased functional coupling within the dorsal striatum may reflect atypical development in children with IGE.

Dental age assessment of North Indian origin children using Nolla\u2019s method in mandibular second molar

BackgroundA cross-sectional study was done on 900 children of North Indian origin, (male = 458; female = 442) aged 10 to 16 years. Digital radiovisiography of permanent mandibular second molar was chosen over higher radiation extra oral projections used for whole arch-like orthopantogram. Each image was evaluated for mean dental age using Nolla’s method of age estimation and was compared to the mean chronological age of children in the study group. The study was conducted to evaluate the applicability of Nolla’s method of age estimation in the North Indian population.ResultsThe mean dental age was found to be significantly underestimated by (1.8 ± 5.5) months in 900 children. The trend of underestimation was more in males ((2.5 ± 4.2) months) as compared to females ((1.1 ± 6.4) months). Both sexes showed underestimation of chronological age till 14 years. However, the dental age and chronological age became similar at 14 years, and overestimation of chronological age was observed afterwards (p value > 0.001).ConclusionNolla’s method of age estimation using radiovisiograph for mandibular second molar is a reliable method in children of North Indian origin, although it underestimates the chronological age. After the average age of 14, dental age surpassed chronological age in the study group. In addition, permanent mandibular second molar was found to be a reliable tooth for dental age estimation.

Dental age estimation of Jordanian children: applicability of Demirjian method

ABSTRACT Objectives: To evaluate the accuracy of Demirjian method in estimating the chronological age of male and female Jordanian children and to establish a new dental age curve if the Demirjian method was not found to be accurate. Methods: Orthopantomograms (OPTs) of 1374 Caucasian Jordanian children (684 females and 690 males) aged 4 to16 years were selected and the dental age was determined by Demirjian method. The chronological ages of the children were obtained by subtracting their birthdates from the date of taking the radiograph. The OPTs were obtained from Archives of Dental Teaching Clinics /XXX and other private orthodontic practices in Irbid and Amman. Results: Demirjian method overestimated chronological age in female and male subjects aged 4 to 8 years. Afterwards, the method underestimated chronological age in females aged 9-11 years and 14-16 years. In male subjects, chronological age was underestimated in subjects aged 9-12 years and 15-16 years. New the dental age curves for Jordanian females and males were constructed. The constants for the quadratic model for the new curves were (b0=-25.341, b1=17.557, b2=-0.623) for females and (b0=-29.809, b1=17.396, b2=-0.595) for males. Conclusion: Demirjian method overestimated the chronological age of Jordanians below the age of 8 years and underestimated the age of Jordanians above 8 years. A new DA standard for Jordanian children was developed and tested for accuracy.

Sequence and chronology of tooth eruption in children and adolescents from Santa Maria - southern Brazil

The literature reports a standard chronological sequence in the eruption of permanent teeth. However, evidence indicates that regional differences may interfere in this process. Thus, the aim of the present study was to compare dental age and chronological age in children and adolescents in a city in southern Brazil to determine the specific pattern in this population. We analyzed the orthodontic records of 250 children and adolescents at the undergraduate course in dentistry of Universidade Franciscana in the city of Santa Maria (southern Brazil). The dental age of each individual was determined through the analysis of panoramic radiographs using the Nolla’s method. Data were also collected on the child’s chronological age, sex, and race. No significant difference was found between average chronological age and that determined using Nolla’s method, indicating that dental and chronological age are similar in this population. However, the eruption periods of all tooth groups were slightly ahead in comparison to the world standard.

DETERMINATION OF DENTAL AGE OF 10-13 YEAR-OLD CHILDREN OF THE CARPATHIAN REGION OF UKRAINE BY THE CAMERIERE METHOD IN COMPARISON WITH THEIR CHRONOLOGICAL AGE

Purpose: to evaluate the chronological and dental age of children in Lviv and the Lviv region aged 10-13 years with the help of the modified formula Cameriere. &#x0D; Methods. Оrthopantomograms 46 children (26 boys and 20 girls) aged 10-13 years from Lviv and Lviv region have been used for this study. A questionnaire was developed for the submission of individual patient data and a standardized format for making their indicators derived from orthopantomograms (OPG). The examination of the area of the lower seven teeth on the left was done using the Cameriere method and the age of the child was evaluated, which was further compared with the chronological age. &#x0D; Results.The obtained results of the study showed a high accuracy and reliability of the estimation of dental age in children up to 10-13 years with the help of the Cameriere formula modified by us. The research is based on the detection of physiological changes (the rate of formation of the roots) in the permanent teeth of children using the X-ray method. Evaluating the results obtained by two methods, among girls and boys of the selected age group, a statistically significant strong correlation between the chronological age and the age calculated by the Cameriere method was revealed. Cameriere research has been carried out in many countries around the world and, in particular, in European countries, by implementing the general formula.&#x0D; Children in the period of occlusive bite remain the most critical in terms of age and, therefore, the determination of the correct time for dental interventions. In this age group, the development of permanent teeth passes through different stages and depends on many factors of the environment, genetic, geographical and food factors. The process of teething also affects many local factors, such as space and space for a permanent tooth in the dental artery and the loss of temporary precursors. Even with a large number of factors affecting the eruption and formation of permanent teeth in children, this method showed high accuracy and independence.&#x0D; In order to assess the Cameriere method among the children under study and its further practical application, a comparison was made between the age obtained using this methodology and the chronological age of the children under study in different age groups, both among boys and girls.&#x0D; Analyzing the obtained data, it was found that the mean of chronological age among the studied boys aged 10-11 (n = 14) was 11.02 ± 0.59 years, and the Cameriere method was 10.63 ± 1.03 years. Student's assessment did not reveal a significant difference between the data (p = 0.22) for the age group of 10-11 years. Further analysis among the studied boys revealed that in the age group 12-13 years the average chronological age was 12.94 ± 0.49 years, and the age was determined by the Cameriere method 12.59 ± 0.63 years, and no significant difference was established between them (p = 0.14).&#x0D; The results of the studies have shown the suitability of the Cameriere formula modified during the process, based on the assessment of open tops and the number of teeth with completed root formation as a marker for the physiological development of the child and one that can be used to determine the child's age.Since studies had a limited age range on a particular sample of dental patients, further studies should evaluate the utility of this method in a larger sample of children in the extended age range of the given region of Ukraine and, if possible, adjust the formula we modified for the stability of the averaged indicators in different samples by age and sex.

Reliability of two dental age estimation methods in children and comparison with their chronological age

Background: Dental age estimation is being performed since Demirjian proposed dental maturity scores. Subsequently, numerous methods were proposed and were estimated worldwide. Although these methods showed high degrees of reliability, ethnic differences were found to affect the accuracy of the dental age. Objectives: The present study evaluated the relationship between chronological age and dental age using Demirjian and Willems methods in children using digital panoramic radiographs. Materials and Methods: Dental age of 60 digital panoramic radiographs of children (males: 34, females: 26) were calculated using the Demirjian scoring method and Willems scoring method. These age values were compared among themselves as well as with chronological age of the children. Further, the comparison was made by dividing all children in the age ranges of 5-7, 7.1-9, 9.1-11, and 11.1-13 years. The correlations between ages among all parameters were statistically significant except age groups 9.1-11 and 11.1-13 years. Conclusion: A significant correlation was observed between chronological age and dental age estimated by Demirjian and Willems methods. Both methods can be useful in the estimation of chronological age in children.

Functional profiles of children with cerebral palsy in Jordan based on the association between gross motor function and manual ability

BackgroundCerebral palsy (CP) is the most common cause of physical disability in childhood. A major challenge for delivering effective services for children with CP is the heterogeneity of the medical condition. Categorizing children into homogeneous groups based on functional profiles is expected to improve service planning. The aims of this study were to (1) to describe functional profiles of children with CP based on the Gross Motor Function Classification System-Expanded & Revised (GMFCS-E & R) and the Manual Ability Classification System (MACS); and (2) to examine associations and agreements between the GMFCS-E & R and the MACS for all participants then for subgroups based on subtypes of CP and chronological age of children.MethodsA convenience sample of 124 children with CP (mean age 4.5, SD 2.9 years, 56% male) participated in the study. Children were classified into the GMFCS-E & R and the MACS levels by research assistants based on parents input. Research assistants determined the subtypes of CP.ResultsThirty six percent of the participants were able to ambulate independently (GMFCS-E & R levels I-II) and 64% were able to handle objects independently (MACS levels I-II). The most common functional profile of children with CP in our study is the “manual abilities better than gross motor function”. An overall strong correlation was found between the GMFCS-E & R and the MACS (rs = .73, p < .001), the correlations vary significantly based on subtypes of CP and chronological age of children. A very strong correlation was found in children with spastic quadriplegia (rs = .81, p < .001), moderate with spastic diplegia (rs = .64, p < .001), and weak with spastic hemiplegia (rs = .37, p < .001).ConclusionsThe GMFCS- E & R and the MACS provide complementary but distinctive information related to mobility and manual abilities of children with CP. Subtypes of CP and chronological age differentiated functional profiles. Functional abilities of children with CP in Jordan have similar patterns to children with CP in other countries. Functional profiles can inform clinicians, researchers, and policy makers.

Chronological Age and Dental Age Using Demirjian in Down Syndrome Children

Down syndrome is a chromosomal abnormality (trisomy 21) characterized by an extra chromosome 21. People with Down syndrome have impairement in mental and physical development, including delayed dental development. Dental age is stage of development of teeth measured by maturation stage of teeth. This study aims to determine or asses the growth or maturation of permanent teeth in children with Down syndrome. This research was a cross-sectional analysis. Analysis test using paired t-test to compare the average of chronological age to dental age, also unpaired t-test for comparing the dental age of children with Down syndrome to normal based on chronological age. The result showed that there was significant difference between chronological age and dental age in children with Down syndrome (p-value 0,05). The conclusion of this study showed that dental age more late than chronological age in children with Down syndrome. In spite dental age in Down syndrome children is descriptively later than in normal.

An epigenetic clock for gestational age at birth based on blood methylation data.

BackgroundGestational age is often used as a proxy for developmental maturity by clinicians and researchers alike. DNA methylation has previously been shown to be associated with age and has been used to accurately estimate chronological age in children and adults. In the current study, we examine whether DNA methylation in cord blood can be used to estimate gestational age at birth.ResultsWe find that gestational age can be accurately estimated from DNA methylation of neonatal cord blood and blood spot samples. We calculate a DNA methylation gestational age using 148 CpG sites selected through elastic net regression in six training datasets. We evaluate predictive accuracy in nine testing datasets and find that the accuracy of the DNA methylation gestational age is consistent with that of gestational age estimates based on established methods, such as ultrasound. We also find that an increased DNA methylation gestational age relative to clinical gestational age is associated with birthweight independent of gestational age, sex, and ancestry.ConclusionsDNA methylation can be used to accurately estimate gestational age at or near birth and may provide additional information relevant to developmental stage. Further studies of this predictor are warranted to determine its utility in clinical settings and for research purposes. When clinical estimates are available this measure may increase accuracy in the testing of hypotheses related to developmental age and other early life circumstances.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-016-1068-z) contains supplementary material, which is available to authorized users.