Willems Method Research Articles

Dental age estimation using Willems methods in children

Dental age estimation using Willems methods in children

Influence of sex and timing of mixed dentition on discrepancies between chronological age and dental age in Taiwanese children

Background/purposeThe aim of this study was to determine the effects of age and sex on the difference between chronological age (CA) and dental age (DA) predicted using the Demirjian and Willems methods in Taiwanese children. Materials and methodsA total of 232 periapical X-ray images were obtained from children aged 5–12 years in Taiwan. Among them, 119 were boys, and 113 were girls. DA was calculated on the basis of the X-ray images of permanent teeth by using the aforementioned methods. The children were stratified by age (5–9 years [early mixed dentition period] vs. 10–12 years [late mixed dentition period]) and sex (boys vs. girls). Statistical analyses were performed to investigate potential age- and sex-based differences in the correlation between CA and DA. ResultsNo significant difference was observed between the mean CA and DA predicted using the Willems method in children with late mixed dentition and in girls. However, the correlation between CA and DA was stronger in children with early mixed dentition than in those with late mixed dentition and also stronger in boys than in girls. ConclusionFor children in mid-Taiwan, age and sex influence the development of permanent teeth. In addition, the correlation between DA and CA is relatively strong for boys in the early mixed dentition period.

Age estimation using orthopantomograms and Willems method among Kenyan children attending dental clinics in Western Kenya

Age estimation using orthopantomograms and Willems method among Kenyan children attending dental clinics in Western Kenya

Evaluation of the Effect of Medications Used in Children with Rheumatic Diseases on Dental Maturation.

The study's main objective is to compare dental maturation in healthy children and those with rheumatic diseases. It also aims to determine the age of children with Pediatric Rheumatic Diseases (PRD), specifically focusing on comparing those receiving medical treatment to those who are not, and to differentiate between biological and non-biological medication recipients, to identify potential differences. This observational cross-sectional study was conducted to assess the dental maturation stages in a cohort of 278 children (126 boys, 152 girls) aged between 6 and 14 years between September 2021 and December 2023. The study population included individuals with PRD requiring dental treatment and systemically healthy children. Digital panoramic radiographs were utilized for the evaluation of dental maturation in both groups. A statistically perfect agreement was found among the dental age (DA) calculated by the researchers (ICC=1.000; p<0.01). A statistically perfect level of agreement was found between the chronological age (CA) of the cases and the DA measured by the Willems method (ICC=0.921; p<0.01). It was found that the difference between the estimated DA and CA was higher in girls and boys in the PRD group who were taking medication. No significant differences were found in DA estimated based on gender and treatment status among individuals with PRD. The Willems method tended to underestimate the age of girls receiving biological treatment while overestimating the age in all other groups.

A comparison of estimated age based on pulp volume from cone beam computed tomography (CT) images and panoramic radiography data with chronological age.

This retrospective study was conducted to evaluate different methods for dental age estimation in children and to examine the feasibility of using cone beam computed tomography (CBCT) data for age estimation. A total of 200 radiographic records (both digital panoramic radiographs and CBCTs) were acquired from 100 children aged 9 to 16 years, all taken on the same dates. Radiographic data was acquired from archived records and included both panoramic radiography and CBCT data belonging to the same individual. CBCT was used when panoramic radiographic data was insufficient. The pulp volume and pulp/tooth volume ratio of the left first molar teeth in the mandible were calculated from the CBCT data using MIMICS software. In addition, age was estimated by the Demirjian and Willems methods from data obtained from panoramic radiography images. Statistical analyses and linear regression analysis were performed as necessary. There was a statistically significant difference between the mean difference between the Demirjian method and chronological age, and between the Willems method and chronological age (p < 0.001). Statistically significance was achieved in a linear regression model created from pulp volume (R2 = 0.098) and pulp/tooth volume ratio (R2 = 0.395) data for the estimated dental age analysis (p < 0.001) and a negative correlation was observed with chronological age. When compared estimated dental age from CBCT data with chronological age, the pulp/tooth volume ratio method yielded results closer to chronological age than using only pulp volume data. When considering both panoramic radiographic age estimation methods and age estimation methods using CBCT data, we found that the results obtained with the Willems method, a panoramic radiographic age estimation technique, provided the closest results to the chronological age. More contributions should be made to the literature regarding the feasibility of age estimation using pulp and tooth volume as an alternative method.

Radiological Evaluation of the Accuracy of Demirjian, Nolla, and Willems Methods for Dental Age Estimation in 3-17-Year-Old Iranian Children.

Background: The stage of tooth formation is one of the most reliable indicators for predicting a patient's developmental age by radiographs. This study compared the accuracy of three distinct dental age estimation methods (Demirjian, Nolla, and Willems) in children aged 3-17 in the northern Iranian population. Methods: This cross-sectional study examined panoramic radiographs of 434 children aged 3-17 from Mazandaran Province, Iran, who had teeth 31-37 present on the left mandible. This study employed the Demirjian, Nolla, and Willems methods to estimate the dental age of the sample and compare it with the chronological age. The data were analyzed using SPSS v16. A paired t-test was used to compare chronological and dental ages. The Pearson correlation was used to correlate the chronological and dental ages. The errors of different methods were compared using the Wilcoxon test. P values < 0.05 were considered significant for all tests except Wilcoxon. For Wilcoxon, a P value < 0.017 was considered significant. Results: The three methods presented differing mean estimated ages. The Demirjian method delivered the highest mean, and all three methods differed significantly when compared in pairs. The results showed that the Demirjian method overestimated chronological age by 0.25 years (P < 0.001) in girls and 0.09 years (P = 0.28) in boys. The Willems method underestimated chronological age by 0.05 years (P = 0.47) in girls and 0.12 years (P = 0.13) in boys. The Nolla method underestimated chronological age by 0.41 years (P < 0.001) in girls and 0.40 years (P < 0.001) in boys. The accuracy of each method varied with the patient's age. Conclusion: According to the findings, the Willems method outperformed the Demirjian method, and the Demirjian method exceeded the Nolla method for estimating dental age in Iranian children aged 3-17. Overall, the Demirjian method overestimated the age of the study population, whereas the other two underestimated it.

Accuracy of different dental age assessment methods to determine chronological age among children with special needs.

This study aimed to validate the accuracy of dental age (DA) based on the dental development of permanent teeth in children with special needs using Demirjian, Willems, and London Atlas methods and to correlate the dental and chronological age (CA) of children with special needs in Malaysia. The panoramic radiographic images belonging to children with special needs from the two teaching dental hospitals in Malaysia aged between 5 and 16 years were included in the study. The evaluation was performed by two observers using three methods (London Atlas, Demirjian, and Willems methods) to estimate the accurate DA. The outcome was determined by comparing the mean of the DA and CA. A total of 52 panoramic radiographs were available for the analysis. The London Atlas and Demirjian methods overestimated the DA with a mean of 0.05 and 0.20 years, respectively, while the Willems method underestimated by 0.19 years. The London Atlas method was highly precise and accurate, while Demirjian and Willems methods were the least precise and accurate. The London Atlas method of DA estimation is highly accurate and valid for children with special needs in the Malaysian population, followed by the Willems and Demirjian methods.

A Comparative Study of the Assessment of the Accuracy of Willems' and Demirjian's Methods in Dental Age Estimation of the Saudi Arabian Population.

The notion that "age is just a number" is sometimes expressed colloquially; however, within the domains of medicine and dentistry, age is not only a numerical value. Rather, it has significant importance in several facets of diagnosis and treatment planning. Demonstrating one's identity is necessary not only in the aftermath of natural calamities or mishaps but also in the context of forensic examination of living persons. Age assessment is a very important tool in forensic odontology and plays a vital role in various fields, including medico-legal matters. The primary focus of the current investigation is to assess the precision and correctness of the data and reliability of Demirjian's method (DM) and Willems' method (WM) for age estimation (AE) among the population of Saudi Arabia. This research was conducted on 300 children from Saudi Arabia, aged seven to 13 years, including both males and females. The assessment of orthopantomography images involved the utilization of both Demirjian's and Willems' methodologies for ascertaining dental age. This determined dental age was then meticulously juxtaposed with the chronological age (CA) of every participant. The data collected underwent a comprehensive statistical analysis, which encompassed the application of the paired t-test. By using both methodologies, it was discovered that the estimated age (EA) exhibited higher values in both men and females compared to the CA. Both Willems' and Demirjian's approaches yielded significantly different results in terms of statistical significance (p = 0.000 and p = 0.000, respectively), as shown by the comparison. When comparing Willems' technique to Demirjian's method, it was found that the population under research showed somewhat greater accuracy levels for AE. However, it is important to note that the disparity between these two approaches was relatively small. Consequently, it is imperative to emphasize the necessity for additional research involving a larger sample size to establish the validation of a more region-specific AE method tailored specifically for the Saudi Arabian population.

Validation of London Atlas for forensic age estimation in Koreans by comparing with Lee's and Willems' methods

This cross-sectional study aimed to evaluate the applicability of the London Atlas for age estimation in the Korean population by comparing with Lee's and Willems' methods. Dental ages of 475 orthopantomographs from Korean individuals aged 4–15 years (mean 10.32 ± 3.31 years) were estimated using the London Atlas, Lee's and Willems' methods. Correlation between dental and chronological age was determined using Pearson's correlation coefficient, and the statistical difference between dental and chronological age was analyzed using a paired t-test. The bias (mean differences), mean absolute error, and root mean square error between dental and chronological age, stratified by age groups and estimation methods, were calculated. Differences in bias and absolute error between sexes were scrutinized using an independent-samples t-test. Age estimates of the three tested methods were combined and compared to those of each individual method. The London Atlas and Willems methods resulted in overestimations, whereas the Lee method led to an underestimation on the entire sample. The overall accuracy was observed in the order of Lee's method, the London Atlas, and Willems' method. The London Atlas demonstrated superior consistency of estimation performance across age groups and no significant differences in estimation performance between sexes. The combination of estimates from the London Atlas and Lee's method resulted in an enhancement in bias and accuracy. We conclude that the London Atlas, due to its bias and accuracy comparable to Lee's and Willems' methods, is applicable for forensic practice in the Korean population.

Age Estimation Using the Demirjian and Willems Methods in a Southern Thai Population

The objective of this study was to test the accuracies of the Demirjian and the Willems dental age estimation methods using the seven left permanent mandibular teeth (excluding the third molar tooth) in children in southern Thailand. Digital panoramic radiographs of 240 Thai children (120 males and 120 females) aged from 8 to 15 years were chosen and separated into eight age groups. Dental age was assessed using the Demirjian and the Willems methods. Differences between the dental age and the chronological age were statistically evaluated by the Wilcoxon signed-rank test. The results showed that the Demirjian method overestimated age by 0.28 years and 0.24 years for males and females, respectively, while the Willems method underestimated age by −0.04 years and −0.23 years for males and females, respectively. Moreover, the mean absolute errors were 0.68 years in males and 0.56 years in females for the Demirjian method and 0.55 years in males and 0.60 years in females for the Willems method. In conclusion, the Willems method was more accurate for dental age estimation compared to the Demirjian method. However, both methods can be applied to estimate the age of children in southern Thailand since the mean error and mean absolute error values were less than one year. Keywords: Dental age estimation, Demirjian method, Tooth developmental stage, Thai population, Willems method

Dental Age Estimation in HIV-infected Children Using Willems Method

Objective: HIV patients differ from other people in terms of dental age. Estimating the age of children abandoned due to HIV is crucial for forensic records. The present study aimed to compare HIV-infected children with healthy controls in terms of dental age using the Willems method. Methods: The study sample consisted of orthopantomograms of 40 HIV patients aged 5-16 years and 50 children aged 6-16 years as the control group. The HIV group included children with vertical infections who had received antiretroviral therapy. The Willems method was used to compare two groups in terms of dental age. Results: Dental age estimation in both HIV and control groups was overestimated using the Willems method. Nevertheless, the overestimation rate was approximately one month in the control group and less than two months in the HIV group, making the method widely applicable for estimating dental age in both healthy children and HIV patients. The dental age of the HIV-infected children was lower than that of the control group. Conclusion: This study indicated a lower dental age in the HIV-infected children compared to the control group. The results demonstrated that dental age estimation using Willems method closely approximated the chronological age of HIV patients.

Demirjian method and Willems method to study the dental age of adolescents in Shanghai before and after 10 years.

The aim of this study was to assess whether the difference in dental ages between 2009 to 2011 and 2021 is affected by environmental factors such as environmental pollution, floating population, and dietary habits. Demirjian and Willems dental age estimation methods were conducted for a Han population of children aged 8 to 14 in Shanghai, China. A total of 1259 digital panoramic radiographs of children aged 8.00-14.99 were estimated. All digital panoramic radiographs were estimated using the Demirjian and Willems methods. Data collected in 2009 to 2011 and 2021 were statistically analysed by paired t-tests. The results show that the Demirjian method overestimates 2009 to 2011 and underestimates 2021 the children's chronological age. When using the Willems method, the age of males was overestimated and the age of females was underestimated from 2009 to 2011, and it was underestimated for both genders in 2021. In conclusion, the difference in dental ages between 2009 to 2011 and 2021 was statistically significant. Factors such as environment and dietary habits have been found to be affected by dental development. However, there are disputes among some researchers about the exact factors, so it is suggested to further study the effects of environmental factors on tooth development.

Validity of age estimation methods and reproducibility of bone/dental maturity indices for chronological age estimation.

This systematic review sought to assess the validity of age estimation methods based on bone or dental maturity indices and their reproducibility through a meta-analysis of validation and reproducibility studies. A systematic online search was conducted in PubMed and Google Scholar. Cross-sectional studies were included. The authors excluded articles without information on validity and reproducibility outcomes, articles not written in English or Italian, and those where it was impossible to obtain pooled reproducibility estimates of Cohen's kappa or the intraclass correlation coefficient (ICC) due to a lack of information on the variability measure. The authors tried to follow the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol. They also considered the PICOS/PECOS strategy to assess the research questions in their included studies; nevertheless, no particular guideline was reported to be consistently followed in their study. Twenty-three (23) studies were selected for data extraction and critical appraisal. The pooled male mean error of the age prediction was 0.08 years (95% CI: -0.12; 0.29), and the pooled female mean error was 0.09 years (95% CI: -0.12; 0.30). Studies using Nolla's method had a mean error closest to zero with a slight overestimation: mean male age prediction error of 0.02 (95% CI: -0.37; 0.41) and mean female age prediction error of 0.03 (95% CI: -0.34; 0.41). Haavikko's method had a mean error of -1.12 (95% CI: -2.29; 0.06) and -1.33 (95% CI: -2.54; -0.13) for males and females, respectively. Cameriere's method also underestimated the chronological age and was the only method with a higher absolute mean error for males than females (males: -0.22 [95% CI: -0.44; 0.00]; females: -0.17 [95% CI: -0.34; -0.01]). Overall, Demirjian's and Willems's methods tended to overestimate chronological age in both males (Demirjian: 0.59 [95% CI: 0.28; 0.91]; Willems: 0.07 [95% CI: -0.17; 0.31]) and females (Demirjian: 0.64 [95% CI 0.38; 0.90]; Willems: 0.09 [95% CI: -0.13; 0.31]). The prediction intervals (PI) overlapped zero for all methods, rendering the difference between estimated and chronological ages not statistically significant for males and females. Cameriere's method showed the smallest PI for both biological genders, while the Haavikko and other methods had the widest intervals. No heterogeneity was observed in inter-examiner (heterogeneity: Q = 5.78, p = 0.888) and intra-examiner (heterogeneity: Q = 9.11, p = 0.611) agreement, so a fixed-effects model was used. For inter-examiner agreement, the ICC ranged from 0.89 to 0.99, and the meta-analytic pooled ICC was 0.98 (95% CI 0.97; 1.00), which was near-perfect reliability. Concerning intra-examiner agreement, the ICCs ranged from 0.90 to 1.00, and the meta-analytic pooled ICC was 0.99 (95% CI 0.98; 1.00), which was also close to perfect reliability. This study recommended the Nolla and Cameriere methods as preferred approaches while mentioning that the Cameriere method was validated on a smaller sample size than Nolla's, thus requiring further testing on additional populations to better assess the mean error estimates by sex. However, the evidence in this paper is of very low quality and offers no certainty.

Research progress of age estimation in juveniles based on Radiography of developmental stages of teeth

Age estimation plays an important role in multiple areas, such as oral clinical medicine and forensic medicine. Teeth development is less influenced by external factors than bone maturity, so the age estimation method based on Radiography to determine the stage of tooth development is widely used. This article reviews several methods for estimating age based on radiographic of teeth development, such as Demirjian method, Nolla method, Willems method, Chaillet method, and methods for estimating age based on the third molar development, and reviews the application and prospects of the above methods.

Performance of the London Atlas, Willems, and a new quick method for dental age estimation in Chinese Uyghur children

BackgroundNumerous dental age estimation methods have been devised and practised for decades. Among these, the London Atlas and Willems methods were two of the most frequently adopted, however dependent on atlantes or tables. A new estimation method less reliant on external measurement could be efficient and economical.AimThis study aimed to evaluate the utility and applicability of the dental age estimation methods of London Atlas, Willems, and a new quick method that subtracts the number of developing teeth from the universal root mature age of 16 years in one of the lower quadrants reported in this work among Chinese Uyghur children.MethodsA comparative cross-sectional study was conducted. Subjects enrolled in the study were screened according to preset inclusion and exclusion criteria. The observer then obtained the dental age from the subjects’ panoramic radiographs based on the estimated rules of the London Atlas, Willems, and a new quick method. Paired t-test was used to compare the accuracy and precision of the above three estimation methods. Independent-sample t-test was used to find the difference between gender.ResultsTotally, 831 radiographs entered the analyses of this study. Among the three methods evaluated, the Willems method, in particular, showed a distinct underestimated tendency. The mean error of the dental age predicted by the London Atlas, the Willems method, and the quick method was 0.06 ± 1.13 years, 0.44 ± 1.14 years, and 0.30 ± 0.63 years, respectively. The mean absolute error was 0.86 ± 0.75 years according to the London Atlas, 1.17 ± 0.89 years under the Willems method, and 0.70 ± 0.54 years under our quick method. No significant difference was found between the chronological age and dental age using the London Atlas, generally for the 10 to 15 years group (p > 0.05), but our quick method for the 15–16 years children (p < 0.05) and Willems method (p < 0.001).ConclusionThe London Atlas outperformed the Willems method with better accuracy and precision among 10–15 years Chinese Uyghur children. Our new quick method may be comparable to the London Atlas for children aged 10–14 and potentially become a more straightforward dental age prediction instrument.

Estimativa da idade pelos métodos de Demirjian e Willems: estudo preliminar na população portuguesa

Introduction: Demirjian’s and Willems’ methods have been studied in different juvenile populations to assess their accuracy and suitability for each population in chronological age estimation. The Willems method seems to be more suitable for age estimation in different populations when compared to the Demirjian method, which, despite this, is still the most widely used. However, to date, there are no studies on the Portuguese population to address this question. Objectives: Evaluate the differences in chronological age estimation with Demirjian’s and Willems’ dental methods to determine which is the most suitable for the Portuguese population. Material and Methods: In 120 orthopantomograms of Portuguese individuals, 64 females, 56 males, aged between 6 and 16 years, the maturation stage of the first 7 teeth of the third quadrant was classified and Demirjian’s and Willems’ methods were applied. Results: In males, both methods overestimated age, with statistically significant differences between estimated age and chronological age. In females, the Demirjian method overestimated age, and the difference was statistically significant. Willems’ method underestimated age, without statistical significance. Conclusions: While in males there seems to be no difference regarding the choice of an age estimation method, in females the use of the Willems method should be preferred.

An assessment of dental age in a select South African sample using the Willems scoring systems

PurposeAge estimation plays a pivotal role in the forensics sciences, medico-legal and clinical dentistry fields. The Willems method has gained significant recognition over the past two decades; however, the accuracy of it varies between population groups and across different regions within a country. Consequently, the present study aimed to investigate the reliability of the Willems scoring systems to a select South African population. MethodsA cross-sectional assessment of 600 digital panoramic radiographs of patients (n = 600: 300 South African Black and 300 South African Indian) between 5.00 and 19.99 years old were employed retrospectively. The dental age was calculated utilizing the Willems et al. (2001) and Willems et al. (2018) scoring systems. Discrepancies between the chronological and dental ages were statistically analyzed. ResultsAn over-estimation of dental age utilizing the Willems et al. (2001) and Willems et al. (2018) scoring systems was recorded in the selected sample of KwaZulu-Natal. A significant statistical difference between the chronological age and estimated dental age was recorded for both methodologies. Therefore, this study attempted to increase the accuracy of the Willems scoring system in a selected sample of South Africa by generating the following two novel population-specific age predictive models (excluding and including third molars). ConclusionThe population-specific model performed better than the Willems scoring systems for the select sample, with the lowest mean errors and an insignificant statistical discrepancy noted between the chronological and dental ages (p-value >0.05). Therefore, these population-specific models may be used for forensic and medico-legal cases within this region.

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

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. 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 13.9years 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, Demirjianmethod 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 ± 2years of chronological age, and intra-observer and inter-observer statistics were calculated. The Cameriere European formula estimated the best dental age compared to the chronological age; the mean underestimation was - 0.4years for both sexes, Haavikko underestimated by - 0.17years, while Demirjian and Willems overestimated by 1.02years and 0.48years, respectively. The most significant difference showed the Demirjian method in 11-year-old and 12-year-old females. The MAE were 0.50years, 1.01years, 0.61years, and 0.78years in males and 0.51years, 1.18years, 0.61years, and 0.70years 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 ± 0.5year 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. 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.

Boosting algorithm improves the accuracy of juvenile forensic dental age estimation in southern China population

Age estimation based on the mineralized morphology of teeth is one of the important elements of forensic anthropology. To explore the most suitable age estimation protocol for adolescents in the South China population, 1477 panoramic radiograph images of people aged 2–18 years in the South were collected and staged by the Demirjian mineralization staging method. The dental ages were estimated using the parameters of the Demirjian and Willems. Mathematical optimization and machine learning optimization were also performed in the data processing process in an attempt to obtain a more accurate model. The results show that the Willems method was more accurate in the dental age estimation of the southern China population and the model can be further optimized by reassigning the model through a nonintercept regression method. The machine learning model presented excellent results in terms of the efficacy comparison results with the traditional mathematical model, and the machine learning model under the boosting framework, such as gradient boosting decision tree (GBDT), significantly reduced the error in dental age estimation compared to the traditional mathematical method. This machine learning processing method based on traditional estimation data can effectively reduce the error of dental age estimation while saving arithmetic power. This study demonstrates the effectiveness of the GBDT algorithm in optimizing forensic age estimation models and provides a reference for other regions to use this parameter for age estimation model establishment, and the lightweight nature of machine learning offers the possibility of widespread forensic anthropological age estimation.

Comparative assessment of the Willems dental age estimation methods: a Chinese population-based radiographic study

BackgroundThe comparison of the two Willems dental age estimation methods (gender-specific (Willems I) and non-gender-specific (Willems II)) has not been fully investigated. Here we aimed to explore the applicability of the Willems dental age estimation in an Eastern Chinese population, which may cast light on the field of dental age estimation.MethodsA total of 1211 oral panoramic radiographs (582 boys and 629 girls) of the Chinese Han population aged 11–16 years old were collected. Dental ages (DAs) were calculated using the Willems method. Statistical significance was set at a p-value < 0.05. Age differences between chronological age (CA) and dental age were analyzed by paired t-tests and mean absolute error (MAE).ResultsThe differences between CA and DA determined by the Willems I method were + 0.44 and + 0.09 years for boys and girls, respectively. When using the Willems II method, these differences were + 0.57 and − 0.09. The MAEs of the Willems I method between DA and CA were 0.95 and 1.00 years in boys and girls, respectively. For Willems II, MAEs were 1.02 and 1.00 years in boys and girls.ConclusionsThis study showed that the Willems I method was more accurate than the Willems II method in the boys’ group for predicting age from a whole scale. In comparison, Willems II is more competitive in the girls' group. Neither method may be satisfactory for 11-to-16-year-old teenagers in Eastern China.