Estimation Of Chronological Age Research Articles

A longitudinal study of DNA methylation as a potential mediator of age-related diabetes risk.

DNA methylation (DNAm) has been found to show robust and widespread age-related changes across the genome. DNAm profiles from whole blood can be used to predict human aging rates with great accuracy. We sought to test whether DNAm-based predictions of age are related to phenotypes associated with type 2 diabetes (T2D), with the goal of identifying risk factors potentially mediated by DNAm. Our participants were 43 women enrolled in the Women's Health Initiative. We obtained methylation data via the Illumina 450K Methylation array on whole blood samples from participants at three timepoints, covering on average 16years per participant. We employed the method and software of Horvath, which uses DNAm at 353 CpGs to form a DNAm-based estimate of chronological age. We then calculated the epigenetic age acceleration, or Δage, at each timepoint. We fit linear mixed models to characterize how Δage contributed to a longitudinal model of aging and diabetes-related phenotypes and risk factors. For most participants, Δage remained constant, indicating that age acceleration is generally stable over time. We found that Δage associated with body mass index (p=0.0012), waist circumference (p=0.033), and fasting glucose (p=0.0073), with the relationship with BMI maintaining significance after correction for multiple testing. Replication in a larger cohort of 157 WHI participants spanning 3years was unsuccessful, possibly due to the shorter time frame covered. Our results suggest that DNAm has the potential to act as a mediator between aging and diabetes-related phenotypes, or alternatively, may serve as a biomarker of these phenotypes.

Age of majority assessment in Dutch individuals based on Cameriere’s third molar maturity index

Radiological examination of the third molar is done in living individuals for estimation of chronological age, especially in the late adolescence. The aim of this study was to assess the application of Cameriere’s third molar maturity index (I3M) to determine whether an individual is 18 years or older (adult) or younger than 18 years (minor) in a sample of Dutch individuals. The sample consisted of panoramic images of 360 individuals aged between 14 and 22 years old. Three observers performed the measurements. Gender was not statistically significant in discriminating adults and minors. The highest value of the Youden index of the receiver operating curve analysis was for the value of I3M<0.08 in discriminating individuals as minor or adult. The specificity (Sp) and sensitivity (Se) results for females were 96.3% and 72.7% respectively. The Sp and Se for males were 95.0% and 84.0% respectively. The probabilities of correctly classified individuals were 83.3% and 88.9%, and Bayes post-test probability was 96.3% and 95.7% in females and males respectively. Obtained results showed that the specific cut-off point of I3M<0.08 may be a useful and reliable method for adult age assessment in a Dutch population.

The Demirjian versus the Willems method for dental age estimation in different populations: A meta-analysis of published studies.

BackgroundThe accuracy of radiographic methods for dental age estimation is important for biological growth research and forensic applications. Accuracy of the two most commonly used systems (Demirjian and Willems) has been evaluated with conflicting results. This study investigates the accuracies of these methods for dental age estimation in different populations.MethodsA search of PubMed, Scopus, Ovid, Database of Open Access Journals and Google Scholar was undertaken. Eligible studies published before December 28, 2016 were reviewed and analyzed. Meta-analysis was performed on 28 published articles using the Demirjian and/or Willems methods to estimate chronological age in 14,109 children (6,581 males, 7,528 females) age 3–18 years in studies using Demirjian’s method and 10,832 children (5,176 males, 5,656 females) age 4–18 years in studies using Willems’ method. The weighted mean difference at 95% confidence interval was used to assess accuracies of the two methods in predicting the chronological age.ResultsThe Demirjian method significantly overestimated chronological age (p<0.05) in males age 3–15 and females age 4–16 when studies were pooled by age cohorts and sex. The majority of studies using Willems’ method did not report significant overestimation of ages in either sex. Overall, Demirjian’s method significantly overestimated chronological age compared to the Willems method (p<0.05). The weighted mean difference for the Demirjian method was 0.62 for males and 0.72 for females, while that of the Willems method was 0.26 for males and 0.29 for females.ConclusionThe Willems method provides more accurate estimation of chronological age in different populations, while Demirjian’s method has a broad application in terms of determining maturity scores. However, accuracy of Demirjian age estimations is confounded by population variation when converting maturity scores to dental ages. For highest accuracy of age estimation, population-specific standards, rather than a universal standard or methods developed on other populations, need to be employed.

Effectiveness of three age estimation methods based on dental and skeletal development in a sample of young Brazilians

ObjectiveThis study compared three methods designed for age estimation. MethodsA sample of 468 radiographs (234 panoramic and 234 carpal radiographs) collected from patients ranging from 5 to 14 years old (mean age: 11.27years old±2.27years) was used. Three age estimation methods: were applied: one founded on dental development, one founded on hand and wrist development, and a method combining both measurements. For each method, the mean error (ME), mean absolute error (MAE), root mean square error (RMSE), and mean percentage of absolute error (MPAE) were quantified. The methods: were compared based on their effectiveness for estimating age in relation to sex and age range. ResultsThe data show that the method exclusively using the development of the hand and wrist had the highest error rates (ME: 1.28M, 1.85F; MAE: 1.64M, 1.96F; RMSE: 1.94M, 2.32F) for both males (M) and females (F). In males, the method combining dental and skeletal development obtained outcomes that were slightly better than the method founded on only dental development (MPAE: 6.99% and 7.47%, respectively). In females, the opposite result was observed (MPAE: 8.48% and 6.59%, respectively). The method founded exclusively on skeletal development significantly overestimated (p=0.001) the age (mean chronological and estimated ages: 11.27 and 12.88, respectively). ConclusionThe methods involving dental development provided more accurate age estimates of chronological age. The method exclusively based on hand and wrist development resulted in outcomes that were highly discrepant from the chronological age.

Listener estimates of talker age in a single-talker, 50-year longitudinal sample

PurposeWhile many studies have shown that listeners make relatively accurate age judgments from hearing talkers’ voices, most have used just one age per talker. The present study evaluated listeners’ age estimation abilities for a longitudinal sample: a single talker recorded over nearly five decades. MethodWe extracted 60 samples from addresses given by a male talker over 48 years. For each sample, listeners gave a direct estimate of his age. We also asked listeners if they could identify the talker, who was known locally, from the recordings. ResultsWhile correlations between the talker’s chronological age and direct estimates of age were generally strong, the relationship was particularly strong when the talker was older than 68 years, although listeners underestimated chronological age by approximately 5 years. When the talker was between 49 and 68 years, direct age estimates were less accurate and less strongly correlated with chronological age. Additionally, direct age estimates were more accurate when listeners recognized the talker. ConclusionsCorroborating cross-sectional studies, our listeners overestimated the talker’s age when he was younger and underestimated it when he was older. However, the crossover between overestimation and underestimation, the point where estimated and chronological ages were equal, occurred at a later talker age for this longitudinal study than in previous cross-sectional studies. Additionally, listeners who recognized the talker made more accurate age estimates when the talker’s chronological age was near the age where they would have known him. We propose future studies explore the relationship between familiarity and estimated age.

Age estimation in Portuguese population: The application of the London atlas of tooth development and eruption

Chronological age estimation from the dental parameters is becoming increasingly important. The London atlas of tooth development is the most recent developed method and represents a modification of the previous older methods.The aim of this study was to evaluate the accuracy of the London atlas for the dental age estimation in the Portuguese population.The study sample included 736 radiographic images (498 females and 238 males) of Portuguese origin, patients of Dental Clinic of Superior Institute of Health Sciences Egas Moniz and Dental Medicine Faculty, University of Lisbon. The age range of the individuals was between 3 and 24 years. Estimated age was compared with the chronological age using the paired t-test.The results showed that there was no statistically significant difference between left and right side of the jaw (p>0.05). Both sides showed an average overestimation of age by one month approximately. Moreover, the significant difference between chronological and estimated age was not observed in the females. However, the significant difference was observed in a sample coming from males (right: p=0.008; left: p=0.003).Our results showed that the London atlas can be potentially used as a tool for age estimation. However, the difference between sexes clearly suggests that separate charts should be made for each sex. Further studies, which will have as a final goal the development of a new method for age estimation using dental parameters, are needed.

Chronological Age Estimation Based on Mandibular Third Molar Development from Digital Panoramic Radiograph in a South Kerala Population

Introduction: Tooth development is the best method in estimating the chronological age of young adults. Demirjan’s method has high value of correlation and observer agreement between chronological age and estimated age. Aim of the study: To assess the chronological age based on developmental stages of mandibular third molar using Demirjian’s method. Materials and methods: A retrospective study of 160 radiographs, among subjects in the age group of 9-25 years who underwent digital panoramic radiographic examination during the last 6 months in the Department of Oral Medicine and Radiology, Pushpagiri College of Dental Sciences, Thiruvalla, Kerala, South India. TenmaIes and ten females were selected for each stage of third molar development (n=160). Developmental stage of the mandibular third molar was assessed using Demirjian’s method. Results: The root formation of mandibular third molars is completed (stage H) at the mean age of 21.4 ± 2.5 years and 21.2 ± 3.2years in females and males respectively. At the mean age of 14.6 ± 1.5 and 13.6 ± 1.9years, the formation of inter-radicular bifurcation (Stage E) had started in males and in females. The data showed that males reached the stages at indicated ages earlier than females. Conclusion: Radiological development of the third molar may be a useful biological variable for estimating the age of a person between teens and early 20s.

Assessing the variability of telomere length measures by means of Telomeric Restriction Fragments (TRF) in different tissues of cod Gadus morhua

The chronological age estimation is still an elusive parameter in many wild animals. Telomeres are nucleoprotein on the ends of chromosomes that shorten throughout the life of many animals. In this study, Telomeric Restriction Fragments length was measured in four different tissues (brain, liver, muscle and skin) of aquaculture cods (Gadus morhua) of different age: larvae (0–110dph); fry (111–180dph), juvenile (181–420dph) and adults (>421dph). Telomeres shortened with increasing age and body length, with differences in telomere rate of shortening depending on the tissue and the developmental stage. The shortening of telomeres with age was significant in brain and liver but it was observed inter-individual variability among individuals of the same age class. Skin and muscle showed no significant shortening pattern with age even tending to elongate in the case of muscle.

Comparison of accuracy between dental and skeletal age in the estimation of chronological age of Down syndrome individuals

This study aimed to evaluate the accuracy of dental age (DA) and skeletal age (SA) methods in order to estimate chronological age (CA) in individuals with Down syndrome (DS), contributing to the Forensic Dentistry and making the identification of these individuals age possible. For this, 278 images of individuals were selected and divided in 2 groups: 216 non-DS patients and 62 with DS. At first, DA was evaluated by Nolla method, on panoramic radiographs, followed by SA, evaluated by Greulich and Pyle method. The linear correlation coefficient of Pearson was used for the analysis of concordance between the methods. Paired t-test with confidence interval was used to evaluate the accuracy and Bland and Altman method was applied to estimate limits of concordance. Complementary to this first analysis, descriptive statistics and ANOVA test were applied for comparison among chronological age (CA), dental age (DA) and skeletal age (SA), with a significance level of 95% (p≥0.05), ordering to observe the differences among them. DA, estimated by Nolla, is underestimated in both, DS and non-DS individuals, and it is more notable in DS individuals. SA estimated by Greulich and Pyle method is overestimated, except for non-DS males. The range of variance is greater in SA and DS than DA and non-DS individuals, respectively. A greater accordance was found for DA×CA if compared to SA×CA, indicating that DA, estimated by Nolla method, is more accurate than SA, evaluated by Greulich and Pyle method, for estimating CA of both, DS and non-DS individuals. However, neither method seems to be precise and more caution is required for age estimation in DS individuals.

Epigenetic age predictions based on buccal swabs are more precise in combination with cell type-specific DNA methylation signatures.

Aging is reflected by highly reproducible DNA methylation (DNAm) changes that open new perspectives for estimation of chronological age in legal medicine. DNA can be harvested non-invasively from cells at the inside of a person's cheek using buccal swabs – but these specimens resemble heterogeneous mixtures of buccal epithelial cells and leukocytes with different epigenetic makeup. In this study, we have trained an age predictor based on three age-associated CpG sites (associated with the genes PDE4C, ASPA, and ITGA2B) for swab samples to reach a mean absolute deviation (MAD) between predicted and chronological age of 4.3 years in a training set and of 7.03 years in a validation set. Subsequently, the composition of buccal epithelial cells versus leukocytes was estimated by two additional CpGs (associated with the genes CD6 and SERPINB5). Results of this “Buccal-Cell-Signature” correlated with cell counts in cytological stains (R2 = 0.94). Combination of cell type-specific and age-associated CpGs into one multivariate model enabled age predictions with MADs of 5.09 years and 5.12 years in two independent validation sets. Our results demonstrate that the cellular composition in buccal swab samples can be determined by DNAm at two cell type-specific CpGs to improve epigenetic age predictions.

Determining the effectiveness of adult measures of standardised age estimation on juveniles in a Western Australian population

The estimation of chronological age through assessment of dental radiographs is well-established and a useful method to assist in the identification of persons in forensic and anthropological scenarios. The objective of our investigation was twofold: (i) to validate the Kvaal et al. age-estimation method on a sample of Western Australian subjects, and (ii) to increase the range of chronological ages to which the Kvaal et al. method can be applied. Our sample size included panoramic radiographs from 74 subjects (aged 12–28 years). A set of ratios were calculated and then used to apply different statistical models of linear regression, in order to generate a final formula to estimate age. The most accurate estimations were obtained from the models generated by the mandibular canine measurement (SEE ± 3.708 years), and for the three mandibular teeth (SEE ± 3.388 years). The results indicate that inclusion of juveniles did not affect final results, and the method still produced estimates acceptable in a forensic framework.

Radiological assessment of age from epiphyseal fusion at the knee joint

Objectives: Age determination is needed in administration of justice, employment, marriage, forensic investigation and identification. This cross-sectional study aimed to investigate the relationship between stages of epiphyseal union at the knee joint and chronological age. Methods: Anterior posterior and lateral knee radiographs of 100 males and 110 females aged 9–19 years were examined. Epiphyseal union was divided into five specific stages in the femur, tibia and fibula. Fusion was scored as stage 0: non-union,stage 1: beginning union, stage 2: active union, stage 3: recent union, and stage 4: complete union. Results: Mean age gradually increased with each stage of union and varied between males and females. A statistically significant difference in mean age was recorded between stages for the three epiphyses. Epiphyseal union occurred earlier in females than in males. A statistically significant difference was observed between the mean age of union for males and females for stages 1 and 2 for the femur, and stages 0, 1, 2 and 3 for the tibia and fibula. Conclusion: The results of this study indicate that radiographic analysis of the knee is a valuable alternative for estimation of chronological age. Keywords: age estimation; epiphysis; fusion; knee joint; radiograph; skeletal maturation

Dental age assessment among Tunisian children using the Demirjian method.

Context:Since Demirjian system of estimating dental maturity was first described, many researchers from different countries have tested its accuracy among diverse populations. Some of these studies have pointed out a need to determine population-specific standards.Aim:The aim of this study is to evaluate the suitability of the Demirjian's method for dental age assessment in Tunisian children.Materials and Methods:This is a prospective study previously approved by the Research Ethics Local Committee of the University Hospital Fattouma Bourguiba of Monastir (Tunisia). Panoramic radiographs of 280 healthy Tunisian children of age 2.8–16.5 years were examined with Demirjian method and scored by three trained observers.Statistical Analysis Used:Dental age was compared to chronological age by using the analysis of variance (ANOVA) test. Cohen's Kappa test was performed to calculate the intra- and inter-examiner agreements.Results:Underestimation was seen in children aged between 9 and 16 years and the range of accuracy varied from −0.02 to 3 years. The advancement in dental age as determined by Demirjian system when compared to chronological age ranged from 0.3 to 1.32 year for young males and from 0.26 to 1.37 year for young females (age ranged from 3 to 8 years).Conclusions:The standards provided by Demirjian for French-Canadian children may not be suitable for Tunisian children. Each population of children may need their own specific standard for an accurate estimation of chronological age.

Age estimation based on Kvaal's technique using digital panoramic radiographs.

Introduction:Age estimation is important for administrative and ethical reasons and also because of legal consequences. Dental pulp undergoes regression in size with increasing age due to secondary dentin deposition and can be used as a parameter of age estimation even beyond 25 years of age. Kvaal et al. developed a method for chronological age estimation based on the pulp size using periapical dental radiographs. There is a need for testing this method of age estimation in the Indian population using simple tools like digital imaging on living individuals not requiring extraction of teeth.Aims and Objectives:Estimation of the chronological age of subjects by Kvaal's method using digital panoramic radiographs and also testing the validity of regression equations as given by Kvaal et al.Materials and Methods:The study sample included a total of 152 subjects in the age group of 14-60 years. Measurements were performed on the standardized digital panoramic radiographs based on Kvaal's method. Different regression formulae were derived and the age was assessed. The assessed age was then correlated to the actual age of the patient using Student's t-test.Results:No significant difference between the mean of the chronological age and the estimated age was observed. However, the values of the mean age estimated by using regression equations as given previously in the study of Kvaal et al. significantly underestimated the chronological age in the present study sample.Conclusion:The results of the study give an inference for the feasibility of this technique by calculation of regression equations on digital panoramic radiographs. However, it negates the applicability of same regression equations as given by Kvaal et al. on the study population.

Biometrics' new identity--measuring more physical and biological traits: Research into the characteristics that are unique to an individual is addressing the need to correctly identify people in a variety of medical, social and security contexts.

There is no need to remember complex combinations of random numbers and characters. From now on, you are the password: your fingerprint, face, iris, gait or odour—any of your potentially unique attributes—can theoretically be used to identify you. This is the idea behind biometrics, which was once confined to the realm of spy movies and high‐security facilities, but is now increasingly common in everyday security checks at borders, for secure payments and logging in to mobile devices. Beyond security, though, biometrics technology is also driving and enabling other applications that include forensic science, data sharing over networks and reducing identification errors in hospitals. > Biometrics is essentially ready for mass application, as the success of the Indian Aadhaar programme demonstrates. While fingerprints and retina patterns are the most well‐known biometric identifiers, they are not the only characteristics that can be used for biometric identification. Physical traits such as the shape of the face, hand or ear, the vasculature in the finger or DNA—so‐called hard biometrics—as well as behavioural characteristics such as gait, signature, voice and typing patterns can all be used to identify individuals (Fig 1). Another large and rapidly expanding category—which includes characteristics such as skin or eye colour, height, weight and tattoos—is known as “soft biometrics” and provides less distinctive, less categorical information, but has the advantage that such traits can be measured from a distance without cooperation from the subject. Even body odour is being actively explored as a practicable biometric identifier (http://www.sciencedaily.com/releases/2014/02/140204073823.htm). Figure 1. Examples of biometric traits. (A) Fingerprints, palm prints, hand vasculature, hand shape and signature. (B) Face, DNA, sclera (on the eyeball), ear shape and typing patterns (keystroke dynamics). (C) Teeth (forensic odontology), gait, voice or speech, iris and retina. Some of these traits—fingerprints, palm prints, face, voice, teeth, ear shape and DNA—are also used in forensics. Reproduced with permission …

Evaluation of third molar development in the estimation of chronological age

The purpose of this study was to evaluate the correlation between chronological age and the degree of third molar mineralization by Demirjian's developmental stages (Demirjian et al., 1973) using panoramic radiography. From a total of 11.396 digital panoramic radiographs of patients from three oral radiology private clinics from the northeast region of Brazil, obtained from January to June 2009, 2097 radiographic images from patients aged between 6 and 22 years were selected. The images were analyzed individually by two obsevers using a 21-inch computer screen and Windows Picture and Fax Viewer. Reliability was achieved by intra- and interobserver evaluation, using the Kappa test. Chronological age, calcification stage, gender and third molar were interrelated using a multiple linear regression model, considering age as a response variable. There was reliability with Demirjian et al.’s developmental stage assesment, displaying a significant relationship between mineralization stages and patients’ age (P<0.05). There was no significant difference between the average age and the calcification stage taking gender and localization of the third molar into consideration. It is possible to estimate chronological age based on Demirjian's stage of a third molar, regardless of gender and location.

"The closer you get …": age, attitudes and self-serving evaluations about older drivers.

The present study investigates the attitudes of older drivers and road safety measures with a particular focus on self-serving evaluations. Driving capacity is considered here as an indicator of awareness of age-related changes that may lead to a higher risk of self-stereotyping, motivating self-serving evaluations with advancing age. In order to test this notion, we used the perceived distance between one's chronological age and the age assigned to the social categories of "older driver" and "old person" as an indicator of age-group dissociation or identification, respectively. Self-serving evaluations were expected depending on the distance between chronological and subjective age estimates. In addition to this, we tested gender and age effects on the specific evaluations. A sample of 350 participants aged 19-88 completed an online questionnaire on negative and positive stereotypes about older drivers and road safety measures. Results indicated in general a more positive than negative view of older drivers; approval with measures to increase road safety by regulating older drivers was comparatively low. Female participants tended to agree more with negative stereotypes and regulative measures than male participants. Regression analyses revealed as well that increasing chronological age was associated with less agreement with negative stereotypes and measures for road safety. Differences between chronological age and subjective age estimates of when a person is old or an old driver were differentially related with the criteria. The closer the chronological age and subjective age estimates were the lower was the agreement with negative stereotypes and measures to regulate road safety. Findings underline in general that road safety enhancing efforts should avoid highlighting chronological age as the sole driving risk factor to circumvent negative stereotyping with ageing and unjustified driving cessation.

Cameriere's third molar maturity index in assessing age of majority

Estimation of chronological age of an individual is one of the main challenges in forensic science. Legally to be able to treat a person as a minor or an adult, it is necessary to determine whether their age of majority (if they are older or younger than 18, in most countries). Methods for estimating age are especially important when an individual in question lacks personal documents or other means of identification. As the dental age differs in various populations, the aim of this study was to evaluate applicability of third molar method for assessing age of majority in Croatia.Cameriere's third molar maturity index (I3M) value of 0.08, measured by the open apices of the teeth, was verified in sample of 1336 panoramic images aged between 14 and 23 years. Chronological age gradually decreased as I3M increased in both genders. Males showed statistically significant advanced maturation when I3M was between 0.0 and 0.3 value. The results indicate that the sensitivity of the test for 0.08 value was 84.3% (95%CI 80.6%, 87.5%) for females and 91.2% (95%CI 88.7%, 93.1) for males. Specificity was 95.4% (95%CI 92.5%, 97.5%) and 91.9% (95%CI 88.8%, 94.3%). The proportions of accurately classified males were 88.8% and that of females 91.5%. The estimated post-test probabilities, of individuals, in other word the probability that a Croatian individual with an I3M<0.08 is 18 years or older is 94.5% for females, and 96.5% for males.With high accuracy, the third molar maturity index should be used as a determinant of the age of majority in Croatia.

The persistence of epiphyseal scars in the distal radius in adult individuals.

The use of radiographic imaging in the estimation of chronological age facilitates the analysis of structures not visible on gross morphological inspection. Following the completion of epiphyseal fusion, a thin radio-opaque band, the epiphyseal scar, may be observed at the locus of the former growth plate. The obliteration of this feature has previously been interpreted as the final stage of skeletal maturation and consequently has been included as a criterion in several methods of age estimation, particularly from the distal radius. Due to the recommendations relating to age estimation in living individuals, accurate assessment of age from the distal radius is of great importance in human identification; however, the validity of the interpretation of the obliteration of the epiphyseal scar as an age-related process has not been tested. A study was undertaken to assess the persistence of epiphyseal scars in adults between 20 and 50 years of age through the assessment of 616 radiographs of left and right distal radii from a cross-sectional population. This study found that 86% of females and 78% of males retained some remnant of the epiphyseal scar in the distal radius. The relationships between chronological age, biological sex and the persistence of the epiphyseal scar were not statistically significant. The findings of this study indicate that the epiphyseal scars may persist in adult individuals until at least 50 years of age. No maximum age should therefore be applied to the persistence of an epiphyseal scar in the distal radius.

Third-molar mineralization and eruption correlated to chronologic age in Turkish children and adolescents

The number of criminal cases involving Turkish juveniles has increased in recent years. To date, there is no method for chronological age estimation according to third-molar mineralization in Western Turkish children and adolescents. The aim of this study was to investigate the mandibular third molar development according to the eight stages (A–H) of the Demirjian method and to compare third-molar development according to gender and age with previous data. The digital orthopantomograms of 1120 white Turkish children (406 boys, mean age 15.17 ± 3.80 years, and 714 girls, mean age 16.83 ± 3.59 years) aged 7 to 22 years, from the Western Anatolia region were retrospectively reviewed. The Turkish population reached stage H at a mean age of 20 years in both genders. Dental mineralization in Western Turkish children was delayed at stages D–G but advanced at stage H compared with that in Turkish children in other regions. Third molar root development can reliably estimate the mean age and age range for a juvenile of unknown chronological age, especially compared with the standard deviation obtained using other techniques for calculating the skeletal age of the hand-wrist or long bones.