The assessment and interpretation of Demirjian, Goldstein and Tanner's dental maturity

Investigating Development in Human Evolution: Specificities, Challenges, and Opportunities

Unlike developmental biologists, paleoanthropologists primarily investigate development using skeletal remains, specifically fossilized and already-formed bones and teeth. Focusing on peri- and/or postnatal growth, they reconstruct development from fragmented "snapshots" of individual trajectories at various ontogenetic stages. These constraints prompt a discussion of what defines development versus growth, and its boundaries in studies of hominin evolution. We explore how paleoanthropologists address the limitations of the fossil record by using diverse methodological and theoretical frameworks to identify developmental markers despite missing data. Finally, we discuss the potential of the "Extended Evolutionary Synthesis," which calls for a greater focus on developmental processes in interpreting phenotypic variation in the fossil record.

Forensic Age Determination Using MRI Scans of the Ankle: Applying Two Classifications to Assess Ossification

In forensic age determination, e.g. for legal proceedings, exceeded age limits may be relevant. To investigate age-related differences in skeletal development, the recommendations of the Study Group on Forensic Age Diagnostics (AGFAD) rely on imaging techniques using ionizing radiation (including orthopantomograms and radiographs of the hand). Vieth et al. and Ottow et al. have proposed MRI classifications for epi-/diaphyseal fusion of the knee joint to determine different age limits. The aim of the present study was to verify whether these two classifications could also be applied to MRI of the ankle.MRI images of the ankle from 333 patients (160 female, 173 male) ranging in age from 10 to 28 years were retrospectively analyzed. T1-weighted turbo spin-echo (TSE) sequences and T2-weighted fat-suppressed sequences were analyzed for the two classifications. The different ossification stages of the two classifications were determined and the corresponding chronological ages were assigned. In addition, gender-specific differences were analyzed. Intra- and inter-observer variability was determined using Cohen's kappa.With the classification of Ottow et al., the completion of the 14th year of life could be determined in both sexes. With the classification of Vieth et al, the completion of the 14th year of life could be determined in both sexes and the 18th year of life in male patients. Intra-observer and inter-observer variability was very good and good, respectively (κ > 0.87 and κ > 0.72).In the present study, it was also possible to use both classifications for MRI of the ankle joint. The method offers the potential of an alternative or at least supplementary radiation-free assessment criterion in forensic age estimation. · MRI scans of the ankle can be used for forensic age determination.. · Classifications developed for the knee joint can also be used on the ankle.. · The applied classifications based on Vieth et al. and Ottow et al. can be used as an alternative or, at the least, an additional method when determining legally relevant age limits.. · Wernsing MF, Malokaj V, Kunz SN et al. Forensic Age Determination Using MRI Scans of the Ankle: Applying Two Classifications to Assess Ossification. Fortschr Röntgenstr 2024; DOI 10.1055/a-2379-8785.

Correlation between dental and skeletal maturity in Korean children based on dental maturity percentile: a retrospective study

BACKGROUND

The correlation between dental maturity and skeletal maturity has been proposed, but its clinical application remains challenging. Moreover, the varying correlations observed in different studies indicate the necessity for research tailored to specific populations.

AIM

To compare skeletal maturity in Korean children with advanced and delayed dental maturity using dental maturity percentile.

DESIGN

Dental panoramic radiographs and cephalometric radiographs were obtained from 5133 and 395 healthy Korean children aged between 4 and 16 years old. Dental maturity was assessed with Demirjian's method, while skeletal maturity was assessed with the cervical vertebral maturation method. Standard percentile curves were developed through quantile regression. Advanced (93 boys and 110 girls) and delayed (92 boys and 100 girls) dental maturity groups were defined by the 50th percentile.

RESULTS

The advanced group showed earlier skeletal maturity in multiple cervical stages (CS) in both boys (CS 1, 2, 3, 4, and 6) and girls (CS 1, 3, 4, 5, and 6). Significant differences, as determined by Mann-Whitney U tests, were observed in CS 1 for boys (p = 0.004) and in CS 4 for girls (p = 0.037). High Spearman correlation coefficients between dental maturity and cervical vertebral maturity exceeded 0.826 (p = 0.000) in all groups.

CONCLUSION

A correlation between dental and skeletal maturity, as well as advanced skeletal maturity in the advanced dental maturity group, was observed. Using percentile curves to determine dental maturity may aid in assessing skeletal maturity, with potential applications in orthodontic diagnosis and treatment planning.

Evaluation of four criteria in assessing third molar maturity for age estimation in Koreans

Third molar maturity is one of the major criteria for estimating human age. This study aimed to determine the most suitable third molar maturity criteria for age estimation in Koreans. The correlation between chronological age and the Demirjian, Köhler, Liversidge, and Thevissen criteria was evaluated using 900 panoramic radiographs of patients aged 15-23 years. The four criteria were applied separately to measure third molar maturity on the same radiograph. The concordance rates between third molars within the same jaw and between jaws were calculated and tested using a paired t-test. Regression was performed to observe the relationship between age and the evaluated stages for each tested criterion. The Demirjian standard showed the lowest root mean square error (1.29 years for males, 1.30 years for females) and highest adjusted R ² (0.753 for males, 0.739 for females) values; however, the differences of the values derived from other criteria were minute. In addition, the symmetry (within the same jaw) and asymmetry (between the upper and lower jaws) of third molar development, which was confirmed in previous Korean studies, was observed only in the Demirjian and Liversidge criteria. Based on the results, we can conclude that all four tested criteria are suitable for age estimation in Koreans. However, the Demirjian and Liversidge criteria can be recommended from the perspective of accurate reflection of the developmental patterns. Further research is necessary to determine whether the results of this study are consistently observed in other populations.

Age estimation of children based on open apex measurement in the developing permanent dentition: an Egyptian formula

Background

Cameriere’s original formula based on open apex measurements is a reliable, clinically applicable method for dental age estimation in different populations children. Dental development may differ between Egyptian children and other ethnic populations which may affect dental age accuracy using Cameriere’s formula.

Aim

Firstly, to verify Cameriere’s original formula on large Egyptian children sample, secondly, to develop an Egyptian-specific formula based on Cameriere’s method.

Material and methods

A prospective cross-sectional study of 762 good quality Orthopantomograms (OPGs) of 5–15 aged healthy Egyptian children selected from Nile Delta governorates between August 2020 and December 2021. Chronological age (CA) was calculated by subtracting birth date from radiograph date. OPGs were analyzed for N0, S, Xi morphologic variables using Sidexis program after that dental age was calculated using Cameriere’s formula then compared to CA. Multiple linear regression model was used to adapt Cameriere’s formula to construct an Egyptian formula. The same sample was used to verify the new formula accuracy.

Results

A total of 1093 OPGs were collected; 762 OPGs which met inclusion criteria were analyzed. Cameriere’s original formula revealed − 0.59- and − 0.53-year underestimation of females and males dental age (DA) respectively (p < 0.001). Regression analysis using the morphologic variables showed that X4, X7, N0 contributed significantly to CA yielding Egyptian-specific formula. New formula showed − 0.12-year male underestimation and 0.1-year female overestimation (p > 0.05).

Conclusion

Egyptian formula was more accurate than Cameriere’s formula in Egyptian children.

Clinical relevance

Egyptian-specific formula decreases the gap between CA and DA, so a relative approximate age is obtained that helps proper diagnosis and treatment planning for orthodontic and pediatric dentistry problems.

The Cameriere, Haavikko, Demirjian, and Willems methods for the assessment of dental age in Croatian children

AIM

This study aimed to evaluate the accuracy and precision of the Cameriere European formula, Demirjian, Haavikko, and Willems methods for estimating dental age in a sample of children with permanent dentition in Croatia.

MATERIAL AND METHODS

The study consisted of a sample of 1576 panoramic radiographs; a sub-sample of 84 OPGs, in which all first seven mandibular teeth were maturated, was excluded from the study. A final sample of 1492 (704 males and 788 females) aged 6.0 to 13.9 years was evaluated. Seven mandibular teeth from the left side of the mandible were analyzed, and dental age (DA) was determined by the Cameriere European formula, Demirjian method from 1976, Haavikko, and Willems methods and compared to chronological age (CA). In addition, the mean age difference (DA-CA), the mean absolute error (MAE) between dental and chronological age, the percentage of the individuals of dental age within ± 0.25 to ± 2 years of chronological age, and intra-observer and inter-observer statistics were calculated.

RESULTS

The Cameriere European formula estimated the best dental age compared to the chronological age; the mean underestimation was - 0.4 years for both sexes, Haavikko underestimated by - 0.17 years, while Demirjian and Willems overestimated by 1.02 years and 0.48 years, respectively. The most significant difference showed the Demirjian method in 11-year-old and 12-year-old females. The MAE were 0.50 years, 1.01 years, 0.61 years, and 0.78 years in males and 0.51 years, 1.18 years, 0.61 years, and 0.70 years in females for the Cameriere European formula, Haavikko, Willems, and Demirjian methods, respectively. Furthermore, the Cameriere European formula showed the highest proportions of individuals with DA within ± 0.5 year difference of the CA, 61.5% in males and 59.6% in females. In addition, the Cameriere method showed the best intra-observer and inter-observer agreements.

CONCLUSIONS

Although the Demirjian method was used previously in Croatian children for legal, medical, and clinical purposes, the Cameriere European formula, Haavikko, and Willems were more accurate in the tested sample. According to our findings, the Cameriere European formula showed the best accuracy and precision in dental age assessment in Croatian children following Haavikko, and we recommend it as the method of the first choice in forensic and clinical analyses.

Accuracy of age estimation and assessment of the 18-year threshold based on second and third molar maturity in Koreans and Japanese

This study aimed to validate Lee’s age estimation method and assess the 18-year threshold in Korean and Japanese populations. We evaluated the maxillary and mandibular second (M2) and third molars (M3) in 2657 orthopantomograms of the Korean and Japanese populations aged 15–23 years (19.47±2.62 years for Koreans, 19.31±2.60 years for Japanese), using Demirjian’s criteria. Dental age was estimated, and correlations between chronological and dental ages were analyzed. Classification performance was calculated based on the 18-year threshold. The relationship between developmental stage and chronologic age was analyzed using multiple linear regression. Our results revealed that Lee’s method was appropriate for estimation in the Korean population. When the Lee’s method was applied to the Japanese population, a lower value of correlation coefficients between estimated and chronological age, and lower specificity were observed. Population differences were observed predominantly in the stages of root development (stages F and G) of M2s and M3s in both jaws and more frequently in females than in males. In the multiple linear regression between developmental stage and chronological age, lower values of adjusted r² were observed in the Japanese population than in the Koreans. In conclusion, the Lee’s method derived from the Korean population data might be unsuitable for Japanese juveniles and adolescents. To support the findings of this study, future studies with samples from multiple institutions should be conducted. Future studies with larger sample sizes are also warranted to improve the accuracy of dental age estimation and confirm the developmental pattern of teeth in the Japanese population.

Nutrition, obesity, and dental development in young adolescents in Chicago

OBJECTIVES

Childhood obesity is a systemic disease with multiple downstream consequences, including shifts in timing of growth and development. It has been documented that children with high body mass index (BMI) show accelerated timing of dental development, but the mechanism for this acceleration is unknown. Prior work has suggested that inflammation and/or nutrition may play a role. We investigate the potential association between diet (caloric intake, macronutrients), obesity, and accelerated dental development.

METHODS

Children and adolescents (age 10-15; n = 112) were recruited from dental clinics at the University of Illinois Chicago. We collected subjects' height, weight, panoramic radiographic records, and each subject filled out a Block Food Frequency Questionnaire.

RESULTS

The only macronutrient level associated with BMI was a negative correlation to Total Fat consumption (p = .01), though this relationship was not significant in the path analysis (p > .05). Regression analyses indicated that BMI (p = .003) and total caloric intake (controlling for BMI; rho = 0.19; p = .04) were both significantly correlated with timing of dental development. However, when a path analysis was conducted, it was revealed that only BMI was statistically significant (p = .008).

CONCLUSIONS

Body mass index percentile, regardless of caloric intake, is positively associated with accelerated dental development. While it is possible that excess caloric intake itself plays a minor role in timing of dental development, we do not see unambiguous evidence for this in our sample. We posit that another mechanism, such as inflammation, may be the link between obesity status and dental development.

Dental age estimation with fewer than mandibular seven teeth: An accuracy study of Bedek models in Turkish children

OBJECTIVES

One or more missing teeth, such as hypodontia, make it difficult to obtain accurate results in age estimation methods. This paper aims to test the accuracy of the models developed by Bedek et al. that can estimate age with fewer than seven teeth for Turkish children.

MATERIALS AND METHODS

Panoramic radiographs of 1118 children (540 girls and 578 boys) aged between 6 and 16 years were evaluated using the Willems method and Bedek models for the entire sample and for different ages and sexes. Differences between dental age (DA) and chronological age (CA) calculated for all methods for each sex and all age groups were analyzed the paired sample t-test and Wilcoxon signed rank test. The accuracy of the DA estimation methods was determined by the proximity of DA to CA by calculating mean absolute error (MAE).

RESULTS

While all Bedek models underestimated CA by 0.2 to 0.1 years, the Willems method overestimated CA by 0.3 years. DA-CA difference in the total sample and girls was statistically significant in all methods. In the total sample, the seven- and four-teeth models had the lowest MAE, while the one-tooth model had the highest MAE.

CONCLUSIONS

Seven- and four-teeth models were the most suitable for age estimation, and all models except the one-tooth model were found to be more accurate than the Willems method in northwestern Turkish children.

CLINICAL RELEVANCE

Especially in children with hypodontia, it may be possible to estimate DA with the use of Bedek models.

Age Estimation in Children by the Measurement of Open Apices in Teeth: A Study in the Western Indian Population

In forensic sphere and clinical dentistry, age estimation is a topic of utmost importance. Various techniques are employed in children to determine age; however, dental development has proven to be an appropriate method because of its low variability. Cameriere's method is a widely accepted method of age estimation in children, which is carried out by measuring the projections of open apices and also the heights of developing permanent teeth seen on panoramic radiographs. The aim of this study is to establish a new formula for age estimation in the Western Indian population by measuring the open apices of mandibular teeth using Cameriere's European formula. For this study, we included 311 panoramic radiographs of healthy children living in Western India (Maharashtra, Gujarat, and Goa) aged 4–15 years which were analysed by two independent researchers. Seven left permanent mandibular teeth were assessed for length and width of open apices. Dental maturity was evaluated using measurements of the left seven permanent mandibular teeth (x_i = A_i/L_i, i = 1,…, 7), the sum of the normalized open apices (s), and the number (N0) of teeth with complete root formation. A linear relationship between open apices, N0, age, and other factors was evaluated with the aid of a stepwise multiple regression model. A stepwise linear regression showed that all parameters, gender, s, N0, and x₅, were significantly associated with age (R = 85%). No statistically significant difference was found between the predicted and actual chronological age of children in the age group of 4–13 years using the regression equation for the Western Indian population. The present research suggests that the new regression formula developed will be more accurate for age assessment in the Western Indian population.

Dental maturation in a Chinese sample using Demirjian method

BACKGROUND

Dental calcification information is relevant for clinical, archaeological, and forensic applications. However, dental maturity measurements in current cohorts of Chinese children are insufficient.

AIM

This study aimed to establish the mandibular dental maturity table and determine the accuracy of dental age estimation using the Demirjian method in a Chinese sample.

SUBJECTS AND METHODS

Permanent mandibular teeth, excluding the third molar, in 2091 panoramic radiographs of 1008 males and 1083 females aged 3-15 were graded, and dental age was estimated according to Demirjian's criteria. Age-of-attainment was calculated with probit regression for each stage by sex, and sex differences were analysed using the Mann-Whitney U test. Dental age was compared with chronological age using paired t-tests.

RESULTS

Although females showed earlier age-of-attainment than males, significant sex differences were only found in stages D-G (p < 0.05). The Demirjian method overestimated the dental age in both males (0.68 ± 1.05 years) and females (0.59 ± 0.97 years).

CONCLUSIONS

The relationship between mineralisation stage and chronological age in this study can be applied as a reference for mandibular dental maturity of Chinese children and adolescents. The Demirjian method overestimated the chronological ages of this sample.

A critical test of twelve methods for estimating age using radiographic staging of developing teeth on a sample of 6- to 15-year-old children from Mérida, Yucatán (México)

Cross-population applicability of osteological and dental methods is a known issue in forensic anthropology, but very little is known about whether differences between populations are due to ancestry, environment effects, or even the statistical approach utilized for developing the methods. This study wishes to add to the discussion of population-specificity of dental age estimation methods and examine the impact of their statistical basis on their accuracy and precision. These parameters were estimated by testing 12 different dental age estimation techniques on a sample of 182 panoramic radiographs of children between the ages of 6 and 15 years (110 girls and 72 boys) from the city of Mérida in Yucatán, México. None of the 12 methods selected is based on Mexican samples. Dental maturation was scored following and methods tested employed two dental scoring schemes: Moorrees, Fanning, and Hunt's (MFH) 13-/14-stage system and Demirjian's 8-stage system. Results show that methods derived from more geographically specific groups do not fare better or worse than methods developed on more diverse and inclusive international samples, even if no methods specific to Mexicans were tested. While some of the methods performed very well, and they were not based on a Mexican sample, this suggests that population-specific dental age estimation methods may be relatively unimportant or that population differences in dental maturation are very small. Other issues seemed to have a greater impact on accuracy and precision, such as age dependency, inclusion of the third molar in age assessments, age truncation and age heaping in reference samples, the dental scoring scheme used, and how predicted age is calculated mathematically. As such, findings in this study suggest that validation tests of age estimation methods may not be a useful or reliable means to assess population differences and that these differences need to be more systematically assessed if an argument is to be made for the increased accuracy and precision of population-specific methods. The statistical basis of dental prediction methods seems to have a more significant role in their accuracy and precision outside of their reference sample.

[Dental age in children with epidermolysis bullosa]

THE AIM OF THE STUDY

Was to assess dental age and the frequency of dental extractions in children with epidermolysis bullosa (EB) compared to controls.

MATERIALS AND METHODS

The study comprised 22 EB children (8 boys and 14 girls aged 4-16 years, mean age 11.1±3.5 years) and 25 healthy children (9 boys and 16 girls aged 4-14 years, mean age 10.1±2.4 years). Dental age was measured on panoramic X-ray by Demirjian method and then compared to child's physical age to estimate retardation or advance in dental maturity.

RESULTS

Only in 5 from 22 EB children dental age corresponded to physical age, there was dental age retardation in 7 patients (13 to 68 months, 27±21.5 months in average), but in 10 dental age exceeded physical (4 to 21 months, 12.9±7.8 months in average). In controls where was only one boy with dental age retardation by 18 months, in 7 children dental age corresponded to physical, in 17 dental age advance by 5-45 months (16.0±11.0 months in average) was revealed. Conclusion. Possible dental age retardation in EB patients should be considered when undertaking dental extractions for orthodontic reasons. For more precise orthodontic treatment timing further studies are needed to correlate dental age, skeletal age and BMI in children with EB.

Age estimation of individuals aged 5–23 years based on dental development of the Indonesian population

Dental development can be used to estimate age for forensic purposes. However, most of the currently available methods are less reliable for the Indonesian population due to population variability. This study presents a new method and evaluates other methods that utilize dental development to estimate the age of Indonesian people. Panoramic radiographs of 304 young Indonesian people aged 5–23 years old were analysed for deciduous tooth root resorption, permanent tooth calcification, and eruption. The extent of tooth root resorption was determined based on AlQahtani’s modified Moorrees et al. method. Tooth calcification was classified based on a modified Demirjian et al. method. Tooth eruption was evaluated based on AlQahtani’s modified Bengston system. The sequence of tooth root resorption, and permanent tooth calcification and eruption were grouped into 19 age categories (from 5–23 years old) in an atlas. The differences between males and females, between maxillary and mandibular teeth, and between right and left teeth were also analysed. There were minimal significant differences of tooth development between males and females, and between the right and left teeth (P > 0.05), while the maxillary and mandibular dental development was significantly different (P < 0.05). The newly developed atlas showed the development of the right side of maxillary and mandibular tooth of combined sex of Indonesian population. Another 34 panoramic radiographs of known-age and sex individuals from Indonesia were assessed using the newly developed Atlas of Dental Development in the Indonesian Population, Ubelaker’s Dental Development Chart, The London Atlas of Human Tooth Development and Eruption by AlQahtani, and the Age Estimation Guide-Modern Australia population by Blenkin-Taylor. Accuracy was assessed by comparing estimated age to actual chronological age using the Bland-Altmand test. Results show that the smallest range of error was found in the Atlas of Dental Development in the Indonesian Population (−0.969 to 1.210 years), followed by The London Atlas of Human Tooth Development and Eruption by AlQahtani (−2.013 to 1.990 years), the Age Estimation Guide-Modern Australia population by Blenkin-Taylor (−2.495 to 2.598 years), and the Dental Development Chart by Ubelaker (−2.960 to 3.289 years). These findings show that the Atlas of Dental Development constructed in this study performs better than the other three methods and presents greater accuracy of age estimation in the Indonesian population.

Key points

Dental development such as deciduous tooth root resorption, permanent tooth calcification, and tooth eruption can be used to estimate age for forensic purposes.

The development of the teeth are influenced by genetic, ethnicity, and sex, therefore an age estimation method must be constructed based on the same population.

There were minimal significant differences in tooth development between male and female, and between right and left teeth, but there was significant difference between maxillary and mandibular teeth.

The Atlas of Dental Development in the Indonesian Population constructed in this study allowed more accurate age estimation of the Indonesian sample than the other methods tested.

Supplemental data for this article are available online at https://doi.org/10.1080/20961790.2021.1886648.

Dental age and skeletal maturity assessment in patients with cerebral palsy

The aims of this study were to calculate the estimated dental age and the degree of skeletal maturity in patients with cerebral palsy and control patients (i.e., without a diagnosis of cerebral palsy) and to compare the findings with the chronological age of patients in both study groups. In this cross-sectional study, the European formula and the Willems method were used to estimate the dental age of 52 patients with cerebral palsy and 104 control patients, all aged between 7 and 15 years. For all patients, their estimated dental age was compared with their chronological age. The degree of skeletal maturity of 35 patients with cerebral palsy and 104 control patients was estimated according to Baccetti's method. There was no statistically significant difference in the deviation of the estimated dental age from the chronological age between patients with cerebral palsy and control patients when the European formula or the Willems method was applied. No difference was found in the frequency of Baccetti's stages between patients with cerebral palsy and control patients in the same age category, for both sexes. To estimate dental age in patients with cerebral palsy, the European formula is preferable for orthodontic purposes and the Willems method is preferable for forensic purposes. Using Baccetti's method it was not possible to detect potential differences in skeletal maturity between patients with cerebral palsy and controls.

Comparison of different machine learning approaches to predict dental age using Demirjian's staging approach

CONTEXT

Dental age, one of the indicators of biological age, is inferred by radiological methods. Two of the most commonly used methods are using Demirjian's radiographic stages of permanent teeth excluding the third molar (Demirjian's and Willems' method). The major drawbacks of these methods are that they are based on population-specific conversion tables and may tend to over- or underestimate dental age in other populations. Machine learning (ML) methods make it possible to create complex data schemas more simply while keeping the same annotation system. The objectives of this study are to compare (1) the capacity of ten machine learning algorithms to predict dental age in children using the seven left permanent mandibular teeth compared to reference methods and (2) the capacity of ten machine learning algorithms to predict dental age from childhood to young adulthood using the seven left permanent mandibular teeth and the four third molars.

METHODS

Using a large radiological database of 3605 orthopantomograms (1734 females and 1871 males) of healthy French patients aged between 2 and 24 years, seven left permanent mandibular teeth and the 4 third molars were assessed using Demirjian's stages. Dental age estimation was then performed using Demirjian's reference method and various ML regression methods. Two analyses were performed: with the 7 left mandibular teeth without third molars for the under 16 age group and with the third molars for the entire study population. The different methods were compared using mean error, mean absolute error, root mean square error as metrics, and the Bland-Altman graph.

RESULTS

All ML methods had a mean absolute error (MAE) under 0.811 years. With Demirjian's and Willems' methods, the MAE was 1.107 and 0.927 years, respectively. Except for the Bayesian ridge regression that gives poorer accuracy, there was no statistical difference between all ML tested.

CONCLUSION

Compared to the two reference methods, all the ML methods based on the maturation stages defined by Demirjian were more accurate in estimating dental age. These results support the use of ML algorithms instead of using standard population tables.

Age estimation in children based on open apices measurement in the Serbian population: Belgrade Age Formula (BAF)

Background: Cameriere's method has been tested in many populations and is widely accepted for dental age estimation.Aim: To establish a new formula for age estimation by measurement of open apices of mandibular teeth based on Cameriere's European formula.Subjects and methods: Panoramic radiographs of 333 healthy Serbian children aged 5-14 years were analysed by two independent researchers. The new formula - Belgrade Age Formula (BAF) - was created and tested on the same Serbian sample. Furthermore, BAF was tested on the Serbian validation sample of 126 children and 2115 Italian children aged 5-14 years.Results: In the Serbian sample, the residuals of the BAF and European formula demonstrated that BAF is significantly better in age estimation than the European formula. No significant difference was found in females from the Serbian validation sample between dental and chronological age when BAF was applied. For males, the BAF and European formula had similar accuracy. In the Italian sample, the mean differences between estimated and real age for the European formula were -0.214 ± 0.934 and 0.109 ± 0.773 for females and males, respectively, while for BAF these differences were 0.182 ± 0.951 and -0.195 ± 0.923 for females and males, respectively.Conclusion: BAF was found to be accurate in the Serbian and Italian populations.

Dental age estimation using radiographs: Towards the best method for Sri Lankan children

Research supports the need for regionally and ethnically specific validated data as the reference base for age estimation techniques. This retrospective study evaluated the accuracy of three dental age estimation methods; Demirjian et al. (1973), Willems et al. (2001), and Blenkin and Evans (2010), for use in Sri Lanka for medico-legal purposes. Panoramic radiographs of 688 Sri Lankan children ranging in age from 8.00 to 16.99 years were used to determine their appropriateness to a Sri Lankan population. The mean age and standard deviations (±SD) were calculated separately for males and females of each age group. Paired t-test and mean absolute errors (MAE) were calculated to compare the calculated dental age (DA) with the chronological age (CA) across the nine age groups. The results revealed the mean CA of the entire sample was 12.38 ± 2.68 years, while the mean DA calculated using the Blenkin and Evans method was 11.83 ± 2.20 years, using the Demirjian et al. method was 12.57 ± 2.53 years, and using the Willems et al. method was 11.99 ± 2.43 years. The Demirjian et al. method consistently overestimated the age of males except in the 2 groups aged over 15 years, whereas the Blenkin and Evans method consistently underestimated the age except for the 11.00-12.99 age range. The method of Willems et al. produced DA quite close to CA up until 12.99 years of age, and then underestimated the age for all higher age groups. In females, the Demirjian et al. method consistently overestimated the age up until 13.99 years and then underestimated the higher age groups, while the Willems et al. method underestimated the age in all age groups except 10.00-10.99 years. The Blenkin and Evans method also consistently underestimated the age except in the 10.00-10.99 and 12.00-12.99-year age groups. The percentages of either overestimation or underestimation calculated for ±0.5 years of the true age were 41.0% for the Blenkin and Evans method, 42.8% for the Demirjian et al. method and 49.1% for the Willems et al. method. In conclusion, while all three methods could be applicable in the estimation of dental age for medico-legal purposes, the Willems et al. method appears to be more appropriate in overall measures for the Sri Lankan reference sample, up to the age of 12.99 years.

Age assessment by Demirjian's development stages of the third molar: a systematic review

OBJECTIVES

Radiographic evaluation of the wisdom teeth (third molar) formation is a widely used age assessment method for adolescents and young adults. This systematic review examines evidence on the agreement between Demirjian's development stages of the third molar and chronological age.

METHODS

We searched four databases up until May 2016 for studies reporting Demirjian's stages of third molar and confirmed chronological age of healthy individuals aged 10-25 years. Heterogeneity test of the included studies was performed.

RESULTS

We included 21 studies from all continents except Australia, all published after 2005. The mean chronological age for Demirjian's stages varied considerably between studies. The results from most studies were affected by age mimicry bias. Only a few of the studies based their results on an unbiased age structure, which we argue as important to provide an adequate description of the method's ability to estimate age.

CONCLUSION

Observed study variation in the timing of Demirjian's development stages for third molars has often been interpreted as differences between populations and ethnicities. However, we consider age mimicry to be a dominant bias in these studies. Hence, the scientific evidence is insufficient to conclude whether such differences exist.

KEY POINTS

• There is significant heterogeneity between studies evaluating age assessment by Demirjian's third molar development. • Most of the studies were subject to the selection bias age mimicry which can be a source of heterogeneity. • Presence of age mimicry bias makes it impossible to compare and combine results. These biased studies should not be applied as reference studies for age assessment.

Automatic Age Estimation and Majority Age Classification From Multi-Factorial MRI Data

Age estimation from radiologic data is an important topic both in clinical medicine as well as in forensic applications, where it is used to assess unknown chronological age or to discriminate minors from adults. In this paper, we propose an automatic multi-factorial age estimation method based on MRI data of hand, clavicle, and teeth to extend the maximal age range from up to 19 years, as commonly used for age assessment based on hand bones, to up to 25 years, when combined with clavicle bones and wisdom teeth. Fusing age-relevant information from all three anatomical sites, our method utilizes a deep convolutional neural network that is trained on a dataset of 322 subjects in the age range between 13 and 25 years, to achieve a mean absolute prediction error in regressing chronological age of 1.01±0.74 years. Furthermore, when used for majority age classification, we show that a classifier derived from thresholding our regression-based predictor is better suited than a classifier directly trained with a classification loss, especially when taking into account that those cases of minors being wrongly classified as adults need to be minimized. In conclusion, we overcome the limitations of the multi-factorial methods currently used in forensic practice, i.e., dependence on ionizing radiation, subjectivity in quantifying age-relevant information, and lack of an established approach to fuse this information from individual anatomical sites.

Estimating age using permanent molars and third cervical vertebrae shape with a novel semi-automated method

Estimating chronological age accurately in young adults is difficult and additional methods are required to increase the accuracy. This study explored a new semi-automated method to assess shape change of third cervical vertebra (C3) with age in the living; comparing this as a method to determine whether individuals could be categorised into being less than 18 years of age (<18), or at least 18 years of age (≥18) with tooth formation of the second and third mandibular molars (M2 and M3). The sample was panoramic and lateral skull radiographs of 174 dental patients (78 males, 96 females aged 15-22 years). Twelve variables were compared in two age categories: younger than 18 and at least 18 years of age in males and females separately using a t-test. Tooth formation of M2 and M3 was assessed. Mean values of eight variables of C3 in males and one variable in females were significantly different between the two age categories (p < 0.05). Results for males showed that the best age indicator for age ≥18 was the ratio between height and width of C3 and for females, the ratio between diagonals. Results for molars showed that M2 was mature in 69% of males and 83% of females, within the expected age range of 14-16 years. M3 was highly variable ranging from stages 6-14 for both; M3 was missing in 24% of males and 28% of females and mature in 14% of males and 15% of females. The conclusion was that shape change of C3 has potential as an additional method to group individuals <18 and ≥ 18 years of age.

Dental age estimation of Omani children using Demirjian's method

Dental age plays a significant role in forensic dentistry, orthodontics and paediatric dentistry, as well as in general diagnosis and treatment planning. Different methods have been developed to determine dental age. One of the most commonly used methods is Demirjian’s method, which was developed in 1973 from research on a large number of French-Canadian children. It is based on the degree of tooth mineralisation by examining the radiological appearance of the lower mandibular left quadrant. The purpose of this study was to assess the dental age of Omani children using Demirjian's method and evaluate the applicability of the method in dental age estimation for Omani children. The sample consisted of 485 digital panoramic radiographs of children (264 males, 221 females) aged between 4.6 years and 16.5 years, and obtained from the records of the Military Dental Centre in Oman. The data were analysed using SPSS. Paired t-tests, intraclass correlation coefficients (ICC) and difference-against-mean plots were used to compare the dental age calculated by Demirjian's method with chronological age. A single examiner scored the radiographs, and intra-observer reliability was evaluated using Cronbach's alpha on data from rescoring one out of every 20 radiographs. For boys, the mean difference between chronological age and dental age for all age groups was 0.10 (95% CI −0.03 to 0.24). For girls, the mean difference between chronological age and dental age for all age groups was 0.05 (95% CI −0.11 to 0.22). Difference-against-mean plots showed no evidence of differential bias by age. For boys, the ICC was 0.896 (95% CI 0.869–0.917); for girls, it was 0.886 (95% CI 0.854–0.911). Difference-against-mean plots for boys (Fig. 1) and girls (Fig. 2) showed some evidence of differential bias by age. In conclusion, the extent of the observed differences was sufficient for doubt to be cast upon the utility of Demirjian’s method for Oman, particularly when it is considered that the method’s most likely application would be in age determination for minors in the workforce.

Dental age estimation using four Demirjian's, Chaillet's and Willems' methods in Kosovar children

BACKGROUND

Tooth formation was recognized as useful body system to assess maturity and predict age. Tooth mineralization is much less affected by the endocrine and different nutritional status than bone mineralization, and teeth formation provides a more reliable indication of chronological age. Demirjian et al. in 1973 presented a scoring system and method for dental age estimation on a sample of French-Canadian children. Chaillet et al. and Willems et al. modified original Demirjian method. This study aimed to evaluate the accuracy of four Demirjian's, Chaillet and Willems methods for age estimation in the children of Kosovo.

MATERIALS AND METHODS

The cross-sectional study was based on the evaluation of the sample of 1022 orthopantomograms (OPTs) of healthy Kosovar children, aged between 5 and 14 years. OPTs were taken from the Radiology unit of University Dentistry Clinical Center of Kosova, as part of random clinical treatment. We tested the accuracy of four methods based on seven mandibular teeth, Demirjian from 1973 (Dem73) and 1976 (Dem76), Chaillet from 2005 (Chaillet) and Willems from 2001 (Willems) and two Demirjian's methods based on different sets of four teeth (Dem76PM1 and Dem76IN2).

RESULTS

For most tested methods, we found statistically significant differences between the chronological age (CA) and dental age (DA) (p < 0.05). In males, the most accurate method were those using four teeth, Dem76IN2 (0.03 years) following by Dem76PM1 (-0.05 years), following those using seven teeth, Willems (-0.14 years), Chaillet (-0.24 years) and Dem73 (0.43 years). In females, dental age was the most accurate for the Willems method (-0.24 years) following Chaillet (-0.35 years), Dem76 (0.43 years) and Dem73 (0.55 years), while Dem76PM1 and Dem76IN2 overestimated by 0.45 years and 0.46 years, respectively. The mean absolute difference between DA and CA were between 0.61 years for the Willems, to 0.78 years for the Dem73 in males, and 0.64 years for the Willems to 0.75 years for the Dem76IN2 in females.

CONCLUSION

The Willems method was the most accurate for estimating a dental age if all seven mandibular teeth are available for analysis, and we found the similar accuracy of Dem76PM1 and Dem76IN2 methods. Therefore, we may encourage their use for age estimation on the Kosovar children.

The growth pattern of Neandertals, reconstructed from a juvenile skeleton from El Sidrón (Spain)

Ontogenetic studies help us understand the processes of evolutionary change. Previous studies on Neandertals have focused mainly on dental development and inferred an accelerated pace of general growth. We report on a juvenile partial skeleton (El Sidrón J1) preserving cranio-dental and postcranial remains. We used dental histology to estimate the age at death to be 7.7 years. Maturation of most elements fell within the expected range of modern humans at this age. The exceptions were the atlas and mid-thoracic vertebrae, which remained at the 5- to 6-year stage of development. Furthermore, endocranial features suggest that brain growth was not yet completed. The vertebral maturation pattern and extended brain growth most likely reflect Neandertal physiology and ontogenetic energy constraints rather than any fundamental difference in the overall pace of growth in this extinct human.

Some inconsistencies in Demirjian's method

Nowadays, given the massive migration movements toward and across EU countries, age assessment can be highly useful for estimating the real age of asylum seekers or in medico-legal assessments of age-disputed children charged with criminal acts. Demirjian et al.'s dental maturity score is currently a dental scoring system universally adopted for age assessment of unidentified children. Here we explore the biological compatibility of Demirjian's scores with respect to the estimation of certain chronological ages of forensic interest through an algorithm based on the theory of constrained graphs integrated with combinatory analysis. Rather than simply respect Demirjian's indications (direct method) on a sample of children, we followed a reverse procedure (indirect method) as follows: i. chronological age selection and identification of the corresponding maturity score (MS); ii. determination of all the possible combinations of dental maturity stages whose sum of the scores is equal to the MS under consideration; iii. checking for all such possible combinations the biological congruity of the state of maturity of each tooth compared to the chronological age initially chosen. By evidencing dental development inconsistencies, our mathematical approach explains why Demirjian's method typically overestimates age. Therefore, even if the method in question remains the recommended way to assess individual dental maturity, it should definitely be considered unsuitable for application in certain forensic scenarios, particularly as regards the most disputed age range 14-16 years.

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

BACKGROUND

The 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.

METHODS

A 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.

RESULTS

The 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.

CONCLUSION

The 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.

Estimation of Correlation between Chronological Age, Skeletal Age and Dental Age in Children- A Cross-sectional Study

Introduction

In the modern era, identification and determination of age is imperative for diversity of reasons that include disputed birth records, premature delivery, legal issues and for validation of birth certificate for school admissions, adoption, marriage, job and immigration. Several growth assessment parameters like bone age, dental age and the combination of both have been applied for different population with variable outcomes. It has been well documented that the chronological age does not necessarily correlate with the maturational status of a child. Hence, efforts were made to determine a child's developmental age by using dental age (calcification of teeth) and skeletal age (skeletal maturation).

Aim

The present study was aimed to correlate the chronological age, dental age and skeletal age in children from Southeastern region of Andhra Pradesh, India.

Materials and Methods

Out of the total 900 screened children, only 100 subjects between age groups of 6-14 years with a mean age of 11.3±2.63 for males and 10.77±2.24 for females were selected for the study. Dental age was calculated by Demirjian method and skeletal age by modified Middle Phalanx of left hand third finger (MP3) method. Pearson's and Spearman's correlation tests were done to estimate the correlation between chronological, dental and skeletal ages among study population.

Results

There was a significant positive correlation between chronological age, dental age and all stages of MP3 among males. Similar results were observed in females, except for a non-significant moderate correlation between chronological age and dental age in the H stage of the MP3 region.

Conclusion

The results of the present study revealed correlation with statistical significance (p<0.05) between chronological, dental and skeletal ages among all the subjects (48 males and 52 females) and females attained maturity earlier than males in the present study population.

Age assessment based on third molar mineralisation : An epidemiological-radiological study on a Central-European population

PURPOSE

The method published in 1973 by Demirjian et al. to assess age based on the mineralisation stage of permanent teeth is standard practice in forensic and orthodontic diagnostics. From age 14 onwards, however, this method is only applicable to third molars. No current epidemiological data on third molar mineralisation are available for Caucasian Central-Europeans. Thus, a method for assessing age in this population based on third molar mineralisation is presented, taking into account possible topographic and gender-specific differences.

METHODS

The study included 486 Caucasian Central-European orthodontic patients (9-24 years) with unaffected dental development. In an anonymized, randomized, and blinded manner, one orthopantomogram of each patient at either start, mid or end of treatment was visually analysed regarding the mineralisation stage of the third molars according to the method by Demirjian et al. Corresponding topographic and gender-specific point scores were determined and added to form a dental maturity score. Prediction equations for age assessment were derived by linear regression analysis with chronological age and checked for reliability within the study population.

RESULTS

Mineralisation of the lower third molars was slower than mineralisation of the upper third molars, whereas no jaw-side-specific differences were detected. Gender-specific differences were relatively small, but girls reached mineralisation stage C earlier than boys, whereas boys showed an accelerated mineralisation between the ages of 15 and 16.

CONCLUSIONS

The global equation generated by regression analysis (age = -1.103 + 0.268 × dental maturity score 18 + 28 + 38 + 48) is sufficiently accurate and reliable for clinical use. Age assessment only based on either maxilla or mandible also shows good prognostic reliability.

Detecting menarcheal status through dental mineralization stages?

Menarche is an indicator frequently used to study variation in growth, development, and related health conditions among members of living populations. As a life event, menarche is often associated with changes in an individual's social identity. The reproductive lifespan, which for females starts with menarche, is a paramount feature of palaeodemographic studies. Determination of menarche status from the skeletal remains of individuals of past populations can be obtained by assessing the developmental status of the iliac crest, as well as the hand and wrist bones, which are, unlike teeth, often poorly recovered in bioarchaeological contexts. The present study seeks to evaluate the link between dental mineralization and menarche in a population of known menarche status. The relationship between permanent teeth mineralization and menarche status was investigated by using data of developing permanent teeth (167 radiographs) rated in accordance with the well-known standards of Demirjian et al. and Moorrees et al. collected among 73 living French females of known menarcheal status. Using correlation ratios, GLMM and CART algorithm, menarcheal status is correlated with mineralization of the premolars. Menarcheal status is predicted correctly for 92 and 77% of radiographs of the learning and validation samples, respectively. Although promising, the results require caution prior to generalization to other populations. The age of menarche in this particular sample may simply coincide with the development of the premolars in this particular sample. Therefore, further investigation applied to populations with various mean ages of menarche is required in order to provide new evidence of variation in human growth and development from the correspondence between the mineralization of the permanent teeth and menarche.

Secular trend in the maturation of permanent teeth in a sample of Turkish children over the past 30 years

This study was performed to evaluate the influence of secular trends on dental maturation among Turkish children over the past 30 years. Orthopantomograms of 757 (385 boys, 372 girls) Turkish children born in the 1980s, 1990s, and 2000s were evaluated. Three groups were formed based on decade with five subgroups by age from 9 to 13 years old for each gender. The number of samples in each age group and gender were matched. The mandibular left seven permanent teeth were evaluated based on formation stage to determine the overall dental maturity score. The groups were compared based on decade and gender. The Bonferroni-corrected Mann-Whitney U test and Kruskal-Wallis tests were used for statistical evaluation. Among 11-, 12-, and 13-year-olds born in the 2000s, girls exhibited significantly more mature dentition than did boys (p<0.01, p<0.05, and p<0.05, respectively). Twelve-year-old girls born in the 1990s and 2000s exhibited significantly more mature dentition than did girls born in the 1980s (p<0.01). Girls generally exhibited more mature dentition than boys. No significant positive secular trends in dental maturity were observed from the 1980s through the 2000s. Dental maturation among Turkish children was not affected by a secular trend.

What automated age estimation of hand and wrist MRI data tells us about skeletal maturation in male adolescents

BACKGROUND

Age estimation of individuals is important in human biology and has various medical and forensic applications. Recent interest in MR-based methods aims to investigate alternatives for established methods involving ionising radiation. Automatic, software-based methods additionally promise improved estimation objectivity.

AIM

To investigate how informative automatically selected image features are regarding their ability to discriminate age, by exploring a recently proposed software-based age estimation method for MR images of the left hand and wrist.

SUBJECTS AND METHODS

One hundred and two MR datasets of left hand images are used to evaluate age estimation performance, consisting of bone and epiphyseal gap volume localisation, computation of one age regression model per bone mapping image features to age and fusion of individual bone age predictions to a final age estimate.

RESULTS

Quantitative results of the software-based method show an age estimation performance with a mean absolute difference of 0.85 years (SD = 0.58 years) to chronological age, as determined by a cross-validation experiment. Qualitatively, it is demonstrated how feature selection works and which image features of skeletal maturation are automatically chosen to model the non-linear regression function.

CONCLUSION

Feasibility of automatic age estimation based on MRI data is shown and selected image features are found to be informative for describing anatomical changes during physical maturation in male adolescents.

Time of mineralization of permanent teeth in children and adolescents in Gaborone, Botswana

The mineralization sequence of permanent dentition can be used to assess the stage of development and age of individuals. The most commonly used methods are based on the assessment of developmental stages of target groups of teeth on one side of the lower jaw. When compared with the rest of the world, fewer studies have been done on dental age in Sub-Saharan Africa, particularly in the region of Southern Africa. The aim of this study was to determine the chronology of mineralization of permanent teeth by the evaluation of developmental stages according to the Demirjian's method from 1973 and to evaluate dental age by using sex-specific self-weighted scores for dental stages and 50th percentile conversion tables of total maturity scores of seven mandibular teeth. We used a sample of panoramic radiographs (OPTs) of black African children and adolescents from the city of Gaborone, Botswana, with the aim of forming an appropriate sample to evaluate the development of the teeth in this socio-geographic environment. The final sample consisted of 1760 OPTs (807 males and 953 females) of individuals aged 6-23 years. The developmental stages of the all permanent teeth in the left side of the maxilla and the mandible were evaluated. Comparing the maxilla and the mandible, we found similar development within different stages for most of the teeth. In comparison to the average age at each stage of development, including the third molars between males and females, it is evident that females are slightly faster in developing permanent teeth, but without statistical significance for most of the developmental stages. Applying 50th percentile conversion tables for calculating the dental age for the first seven mandibular teeth, 616 OPTs of the children (299 males and 317 females), aged 6.08-16.80 years, were evaluated and their dental age was calculated. Mean dental age was overestimated in comparison to chronological age by 1.25±1.11 years and 0.72±1.02 years for males and females, respectively (p<0.001). These findings indicate that Demirjian's method from 1973 is not suitable for routine use and that there is a need for establishing specific standards for Botswana children of black African origin for dental age estimation.

Testing international dental maturation scoring system and population-specific Demirjian versions on Saudi sub-population

Objectives: The purpose of this study was to test the applicability of the Demirjian method and revised versions for estimating chronological age (CA) from dental age (DA) in a sample of children. Study Design: A sample of 252 individuals of known age (4 to 14 yrs), sex (males: 125, females: 127), and ethnicity (Saudi) was collected. Each individual was aged using the original Demirjian method and revised versions, including Saudi, Kuwaiti, Belgian, and revised international curves. The differences between dental age and chronological age were analyzed using paired sample t-tests with Bonferroni corrections and multinomial regression tests at the 0.05 level of significance. Results: The results indicated an over-aging of the sample as a whole by about 10 months using Demirjian tables, 5.5 months using Kuwaiti tables, 24.7 months using Belgian tables, and 5 months using revised international tables. The sample was under-aged by 0.6 month using Saudi tables. The overall discrepancies between CA and DA were statistically significant (P < 0.0001) for all methods with the exception of Saudi curves. Conclusions: The findings suggest that the Saudi population method is most accurate on a Saudi population.

Key words:Age estimation, juvenile, forensic dentistry, Saudi Arabia.