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

Global lens of Willems' method for dental age estimation: where we are and where we are going - umbrella review

This umbrella review aimed to evaluate the evidence behind the Willems method for dental age estimation and detect methodological limitations in the existing systematic reviews. The study followed the Preferred Reporting Items for Overviews of Reviews (PRIOR), with the protocol registered in PROSPERO (CRD42023487745). Seven databases, including grey literature sources, were searched (Medline/PubMed, Scopus, LILACS, SciELO, Web of Science, Open Grey and Open Access Theses and Dissertations). Systematic reviews of cross-sectional studies on the Willems method were included. Two calibrated reviewers independently conducted study selection, data extraction, quality assessment (AMSTAR-2) and risk of bias (ROBIS). Five systematic reviews published between 2017 and 2022 were included. Combined sample sizes ranged from 9347 to 17,741 individuals aged 2.2 to 18 years. Meta-analyses reported minor overestimations in dental age, with differences varying by sex and ethnicity. However, significant methodological shortcomings were identified, such as lack of protocol registration, limited search strategies, and inadequate assessment of the risk of bias. All systematic reviews were rated as critically low quality and with a high risk of bias. The Willems method was deemed appropriate for dental age estimation by most studies, but methodological limitations of existing systematic reviews underscore the need for more rigorous research and improved standards.

Dental color measurement to estimate age in adults: a systematic review and meta-analysis

Age estimation is a major challenge in anthropology and forensic odontology laboratories, as well as in judicial settings, as one of the tools used in human identification. The aim of this study was to evaluate the usefulness of age estimation methods based on the accurate measurement of tooth color changes. A systematic review was carried out following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and in compliance with Cochrane criteria recommendations (PROSPERO registration number CRD 42022343371). An electronic search was performed in the following databases: Pubmed, Web of Science, Medline, Current Contents Connect, SciELO, KCI-Korean Journal Database, Derwent Innovations Index and Russian Citation Index. The search strategy yielded a total of 18 articles. A randomized meta-analysis model of the results for the CIE L*a*b* color variables stratified by age (less than 30 years, 30-60 years, 60 years and older) was performed with 9 of the 18 studies included in this systematic review. According to our results, sex and location of color measurement are the most influential factors in color estimation. All studies were carried out in healthy anterior teeth by spectrophotometry as the most commonly used method for color measurement, with CIE L*a*b* being the most commonly analyzed parameters. Studies based on age as a dependent variable showed R2 values between 0.28 and 0.56, being higher in ex vivo teeth. Studies based on age as an independent variable showed R2 values ranging from 0.10 to 0.48. The random model showed high heterogeneity for the L*, a* and b* parameters in all age groups, which is explained by discrepancies in age range and non-standardized conditions for color measurement. This systematic review highlights the need to protocolize age estimation studies that measure tooth color, in order to apply this method in different forensic settings.

Correlation between dental age and chronological age of Taiwanese children on panoramic X-ray images by different evaluation methods

BACKGROUND

Accurate age estimation is vital in forensic medicine and clinical dentistry. The Demirjian method is commonly used for this purpose, but its applicability to Asian individuals is understudied. The present study evaluated the accuracy of dental age (DA) estimation for Taiwanese children by using the Demirjian, Willems, and modified Demirjian methods, comparing these estimates to those of chronological age (CA) based on panoramic X-ray images.

METHODS

A total of 232 Taiwanese children aged between 5 and 12 years underwent panoramic X-ray scans. Their permanent teeth were assessed using the Demirjian, Willems, and modified Demirjian methods to estimate DA. Regression analysis was used to determine the correlation between CA and DA, with linear regression equations established using SPSS statistics software to identify differences.

RESULTS

The Willems method had the lowest mean absolute error and the smallest mean difference between DA and CA among the 3 age estimation methods analyzed ( p < 0.001). The R2 value for the difference between DA and CA was 0.831 for the Willems method, 0.813 for the Demirjian method, and 0.782 for the modified Demirjian method ( p < 0.001). The Willems method had the highest correlation with CA, with the linear equation for Taiwanese children being CA = 0.822 × DA + 1.093. For comparison, for the Demirjian method, the equation was CA = 0.894 × DA + 0.165.

CONCLUSION

The effectiveness of predictive methods varies across ethnicities, and therefore, region-specific formulas are required. For Taiwanese children, the Willems method predicts CA most accurately. This study contributes to the fields of legal medicine and clinical dentistry by demonstrating the accuracy of DA in predicting CA.

Age estimation using dental and hand-wrist radiography among a sample of Egyptian children

The current study aimed to evaluate the accuracy of Willems, Cameriere's and Greulich and Pyle method in age estimation among a sample of Egyptian children aged 8-16 years based on analysis of 140 panoramic dental X-ray and hand-wrist radiographs (70 girls and 70 boys). Using Willems method, the mean dental age underestimated chronological age by (0.20 ± 0.91 years) for boys and by (0.24 ± 1.33 year) for girls; these differences were not statistically significant. Also, Cameriere's method underestimated chronological age in both sexes by mean difference of (1.10 ± 1.22 year) in boys and (1.13 ± 1.31 year) in girls; these differences were statistically significant. Regarding Greulich and Pyle atlas, the mean of skeletal age was overestimated when compared to the real age in boys with a mean difference (0.04 ± 0.86 year). In girls; the age was underestimated by a mean difference of (0.15 ± 1.32 years) when compared to chronological age; these differences were not statistically significant. Comparing the two dental methods, the mean absolute error using Willems method was less than one year (0.94 and 0.96 years) in boys and girls respectively, while in Cameriere's method, it was more than one year in both groups. Moreover; the mean absolute error using Greulich and Pyle atlas was less than two years (1.02 and 1.38 years) in boys and girls respectively. Since Willems and the atlas methods were more accurate, the combination of both of them could be used for age estimation in the Egyptian population.

Comparative Analysis of Dental Age Estimation: A Systematic Review and Meta-analysis Assessing Gender-Specific Accuracy of the Demirjian and Nolla Methods Across Different Age Groups

Chronological age (CA) estimation is essential in medicine, forensics, and law. Teeth are often used for this due to their reliability. The Demirjian and the Nolla methods are used to estimate dental age (DA). Both methods have strengths and weaknesses; the Demirjian method usually overestimates age, whereas the Nolla method underestimates it. Their accuracy varies among different populations. Our objective is to compare the accuracy of these methods across various age groups and to probe the effect of gender. We searched PubMed, Scopus, the Excerpta Medica database (EMBASE), the Cochrane Library, and the Web of Science for relevant articles until March 2024. We then screened for comparative studies using the Demirjian and the Nolla methods. We used the RevMan 5.4 software package (The Cochrane Collaboration, London, UK) to compare the accuracy of both methods in estimating chronological age in both genders across age groups ranging from five to 16 years. All data were pooled using a random effects model, and relevant forest plots were generated. The accuracy was calculated based on the pooled mean difference between the chronological age and that estimated by each method. Our literature search identified 25 articles for inclusion in the review. The Demirjian method overestimated the age in males by 0.71 years in the six to 6.99 age group and an average overestimation of 0.5 years across all age groups. In females, the overestimation was 0.82 years in the 11-11.99 age group, but the average overestimation was 0.5 years. Overall, the Nolla method underestimated the age of males by 0.28 years and females by 0.25 years. Estimations from both methods were 0.7 years apart on average. In conclusion, while the Demirjian and Nolla methods have unique advantages, using them together can provide a more robust and reliable age estimation. Forensic practitioners can determine the best approach by considering population-specific accuracy, age group and gender, and the case context. Combining both techniques offers cross-verification, comprehensive assessment, bias mitigation, and enhanced reliability.

Dental evidence for extended growth in early Homo from Dmanisi

Human life history is characterized by an extended period of immaturity during which there is a disjunction between cerebral and somatic growth rates1. This mode of ontogeny is thought to be essential for the acquisition of advanced cognitive capabilities in a socially complex environment while the brain is still growing2. Key information about when and how this pattern evolved can be gleaned from the teeth of fossil hominins because dental development informs about the pace of life history3-5. Here we show that the first evolutionary steps towards an extended growth phase occurred in the genus Homo at least 1.77 million years ago, before any substantial increase in brain size. We used synchrotron phase-contrast tomography6 to track the microstructural development of the dentition of a subadult early Homo individual from Dmanisi, Georgia. The individual died at the age of 11.4 ± 0.6 years, shortly before reaching dental maturity. Tooth growth rates were high, similar to rates in living great apes. However, the Dmanisi individual showed a human-like delayed formation of the posterior relative to the anterior dentition, and a late growth spurt of the dentition as a whole. The unique combination of great-ape-like and human-like features of dental ontogeny suggests that early Homo had evolved an extended growth phase before a general slow-down in life history, possibly related to biocultural reproduction7 rather than brain growth.

Accuracy of second and third molar maturity indices, Olze, Haavikko, and Demirjian methods for 14- and 16-year-old age thresholds assessment in Croatian children and adolescents

This study explores the reliability of four established legal age threshold estimation approaches in a Croatian sample. We applied Haavikko stages, Demirjian stages, Olze's third molar eruption stages, and second and third molar maturity indices measurement in 593 orthopantomograms of Croatian children and adolescents aged 11.00-20.99 years old. The left mandibular second and third molar were assessed. Logistic regression analysis was conducted to test the significance of predictive variables. Logistic Receiver operating characteristic (ROC) curves were performed to evaluate the classification ability of variables for estimating 14- and 16-year-old thresholds. The areas under the ROC curve (AUC), accuracy (Acc), sensitivity (Se), specificity (Sp), Positive Likelihood Ratio (LR +), Negative Likelihood Ratio (LR-), and Bayes post-test probability (Bayes PTP) were calculated to evaluate classification performance. Results suggest that the combination of I2M&I3M is the best classifier for the 14-year-old threshold (AUC = 0.879); for males alone, I2M is an even better classifier (AUC = 0.881). The highest Acc 80.1% (95%CI, 75.9%-83.9%), Bayes PTP 86.5% (95%CI, 82.8%-89.7%) and Sp 88.9% (95%CI, 83.0%-93.3%) were by I3M < 0.81 & I2M < 0.03 in total samples; the highest Acc 86.1% (80.6%- 90.6%), Bayes PTP 87.2% (95%CI, 81.7%- 91.4%) and Sp 87.8% (95%CI, 78.2%- 94.3%) were by I2M < 0.01 in males, Acc of Haavikko Ac and Demirjian H stage in second molar is very close with slightly lower Bayes PTP and Sp. I3M is a good classifier for 16-year-old threshold (AUC = 0.889). The cut-off value I3M < 0.34 can be used to classify the 16-year-old threshold with Acc of 80.6% (95%CI, 77.2%-83.7%), Sp of 83.4% (95%CI, 79.0%-87.3%), and 81.7% (95%CI, 78.4%-84.8%) Bayes PTP. In conclusion, to classify the 14-year-old threshold, a pair of cut-off values I3M < 0.81 & I2M < 0.03 can be used in Croatian females; I2M < 0.01, Demirjian H stage, Haavikko Ac stage in second molar, and the pair I3M < 0.81 & I2M < 0.03 can all be used in Croatian males. I3M < 0.34 can classify the 16-year-old threshold in Croatian populations.

Do Tunisian children with unilateral cleft lip and palate differ from normal individuals in dental maturity? A pilot study

INTRODUCTION

Cleft lip and palate (CLP) is the most common congenital malformation of the head and neck. Children with CLP often exhibit dental anomalies.

AIM

To evaluate the dental age (DA) of unilateral CLP in Tunisian children.

METHODS

This was a cross-sectional study carried out in the department of pediatric dentistry at the University Hospital La Rabta, Tunis. Patients aged between 5 and 14 years, with no other congenital anomalies or syndromes in the craniofacial region other than CLP, were included. The patients' chronological ages were first calculated in years and months. DA was assessed in panoramic radiographs using Demirjian's method. The score of each stage is allocated, and the sum of the scores provides an evaluation of the subject's dental maturity.

RESULTS

Fifty-three patients were included in the present study. No difference was observed between the two groups regarding the dental age. A strong and positive correlation between the DA and the chronological age in the two groups was observed (r=0.826). Estimated regression showed that chronological age alone explained 57,4% (r2=0.574) of the dental age variation in the study group and 64.5% (r2=0.645) in the control group.

CONCLUSION

For dental management, CLP children should have the same approach in orthodontics and pediatric dentistry as individuals without clefts, with a focus on the individualization of diagnosis and treatment planning.

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

Background/purpose

The 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 methods

A 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.

Results

No 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.

Conclusion

For 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.

Legal Dental Age Thresholds Estimation in Croatian Children and Adolescents: Accuracy of the Olze, Haavikko, and Demirjian Methods

Objective

This study aimed to explore the accuracy of three established approaches for legal age threshold estimation in a Croatian sample.

Materials and methods

Olze's third molar eruption stages, Haavikko stages, and Demirjian stages were applied in 583 orthopantomograms of Croatian children and adolescents aged 10.00-20.99 years old. The left mandibular second and third molar were assessed. Tooth formation and eruption chronology were established. Receiver operating characteristic (ROC) curves were performed to assess the classification ability of predictive variables for estimating 16- and 18-year-old thresholds.

Results

Havikko stage, Demirjian stage and eruption stages in tooth 37 performed poorly for 16-year-old and 18-year-old thresholds. Tooth 38 provide value information for these two age thresholds estimation. For 16-year-old threshold, Haavikko Stage Rc and Demirjian Stage G both yielded Sp over 98% and Bayes PTP over 95% in both sexes. yielded Sp over 98% and Bayes PTP over 95% in both sexes. Eruption stage C yielded Sp over 98%, Bayes PTP over 96% in males, and lower in females (Sp 96.7%, Bayes PTP 88.2%). For 18-year-old threshold, Haavikko stage Ac and Demirjian stage H both yielded 100% Sp and Bayes PTP. Eruption stage D yielded Sp over 96%, Bayes PTP over 90% in both sexes, slightly higehr in females than males. Mean age of tooth 37 at Haavikko stage Ac, Demirjian stage F, H and eruption stage D was statistically lower in females (p<0,05).

Conclusion

Croatian population-based data on dental maturity were presented. Haavikko stage Rc, Demirjian stage G, eruption stage C and respective advanced stages in tooth 38 are effective for 16-year-old threshold classification. Haavikko stage Ac, Demirjian stage H and eruption stage D are effective for 18-year-old threshold classification.

Demirjian's and Cameriere's Methods for the Assessment of Dental Age Estimation in Children from a Southern Brazilian City

The chronological age estimation of living individuals is a crucial part of forensic practice and clinical practice, such as in orthodontic treatment. It is well-known that methods for age estimation in living children should be tested on different populations. Ethnic affiliations in Brazil are divided into several major groups depending on the region, with the south of Brazil being known for its German immigration. (1) Background: This study aimed to evaluate the correlation between chronological age and dental age using Demirjian's method and Cameriere's method in a group of children from Joinville, South Brazil to investigate if both methods can be used to estimate dental age in this population. (2) Methods: The sample consisted of 229 panoramic radiographs (119 were males and were 110 females) from Brazilian children (ages ranging from 6 to 12 years). The chronological age at the time of the panoramic radiographic exam was calculated for each child. The dental age was estimated according to Demirjian's method and Cameriere's method. All continuous data were tested for normality by using the Shapiro-Wilk test. The Pearson correlation coefficient test was applied. An alpha of 5% (p < 0.05) was used for all analyses. (3) Results: The mean chronological age was 8.75 years. According to Demirjian's method, the mean dental age was 9.3 years, while according to Cameriere's method, the mean dental age was 8.66 years. A strong correlation between chronological age and dental age according to Demirjian (r = 0.776 and p < 0.0001) and Cameriere (r = 0.735 and p < 0.0001) was observed for both genders. (4) Conclusions: Both methods presented a good correlation with chronological age in the studied population and could be used to assess dental age in this population.

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.

A fully automated classification of third molar development stages using deep learning

Accurate classification of tooth development stages from orthopantomograms (OPG) is crucial for dental diagnosis, treatment planning, age assessment, and forensic applications. This study aims to develop an automated method for classifying third molar development stages using OPGs. Initially, our data consisted of 3422 OPG images, each classified and curated by expert evaluators. The dataset includes images from both Q3 (lower jaw left side) and Q4 (lower right side) regions extracted from panoramic images, resulting in a total of 6624 images for analysis. Following data collection, the methodology employs region of interest extraction, pre-filtering, and extensive data augmentation techniques to enhance classification accuracy. The deep neural network model, including architectures such as EfficientNet, EfficientNetV2, MobileNet Large, MobileNet Small, ResNet18, and ShuffleNet, is optimized for this task. Our findings indicate that EfficientNet achieved the highest classification accuracy at 83.7%. Other architectures achieved accuracies ranging from 71.57 to 82.03%. The variation in performance across architectures highlights the influence of model complexity and task-specific features on classification accuracy. This research introduces a novel machine learning model designed to accurately estimate the development stages of lower wisdom teeth in OPG images, contributing to the fields of dental diagnostics and treatment planning.

Evaluating legal age of 18 years through observation of third molars using Gambier et al. method in an orthopantomographic sample of subadults from South India

In forensic practice, medicolegal physicians are often tasked with estimating age using dental evidence. This calls for an uncomplicated, reliable, and reproducible method for dental age estimation, enabling physicians to proceed without specific odontological expertise. Among various dental methods, third molar eruption analyses are less complicated and easier to perform. In our study, we explored the effectiveness of Gambier et al.'s scoring system, which examines the eruption of all third molars. We retrospectively analysed 1032 orthopantomograms (528 males and 504 females) of individuals aged between 15 and 24 years. The mean chronological age increased with the progression of stages (1 to 3) and phases (A to D) of the third molar eruption for both sexes. In terms of stages, none showed significant discrimination between minors (<18 years) and adults (>18 years), especially for males. However, Gambier's phase D displayed a relatively high likelihood of being 18 years or older, with an overall 85.9 % of males and 95.7 % of females having all third molars in stage 3 being 18 years or older. While the tested method could be helpful in indicating the completion of the 18th year of life, caution is advised (due to a high percentage of false positives), and it should be used alongside other age assessment methods by experts.

Machine Learning Supported the Modified Gustafson's Criteria for Dental Age Estimation in Southwest China

Adult age estimation is one of the most challenging problems in forensic science and physical anthropology. In this study, we aimed to develop and evaluate machine learning (ML) methods based on the modified Gustafson's criteria for dental age estimation. In this retrospective study, a total of 851 orthopantomograms were collected from patients aged 15 to 40 years old. The secondary dentin formation (SE), periodontal recession (PE), and attrition (AT) of four mandibular premolars were analyzed according to the modified Gustafson's criteria. Ten ML models were generated and compared for age estimation. The partial least squares regressor outperformed other models in males with a mean absolute error (MAE) of 4.151 years. The support vector regressor (MAE = 3.806 years) showed good performance in females. The accuracy of ML models is better than the single-tooth model provided in the previous studies (MAE = 4.747 years in males and MAE = 4.957 years in females). The Shapley additive explanations method was used to reveal the importance of the 12 features in ML models and found that AT and PE are the most influential in age estimation. The findings suggest that the modified Gustafson method can be effectively employed for adult age estimation in the southwest Chinese population. Furthermore, this study highlights the potential of machine learning models to assist experts in achieving accurate and interpretable age estimation.

Age Estimation in Brazilian Adults Using the Pulp/Tooth Ratio of the Maxillary Canine and Mandibular Second Premolar

(1) Background/Objectives: Accurate determination of chronological age is crucial in legal dental identification. This study aimed to compare the effectiveness of different formulas in estimating the age of a Brazilian subpopulation by analyzing the pulp/tooth ratio of the maxillary canine and mandibular second premolar in panoramic and periapical radiographs. (2) Methods: The sample consisted of panoramic and periapical radiographs of 247 individuals. The file of each radiograph was opened in the Adobe Photoshop CS4® program to outline and obtain values in pixels for calculating the pulp/tooth ratio. Statistical analysis was conducted using the SPSS program, with a significance level set at 5%. (3) Results: The interclass correlation coefficient demonstrated excellent intra-observer agreement (0.990-0.999). The determination coefficients (R2) suggested that only 30-35% of the actual age results could be explained by the pulp/tooth ratio. The smallest differences were observed with Cameriere's formula for the mandibular second premolar on panoramic radiographs (+4.1 years). The greatest differences were found with the formulas for the mandibular second premolar in panoramic radiographs of the Korean (+12.5 years) and Portuguese (-12.1 years) populations. (4) Conclusions: The equations employed showed little agreement between the actual age and the estimated age.

Association between dental age and malocclusions: a systematic review

BACKGROUND

The evidence in the literature suggests that some skeletal or dental malocclusions are involved with dental development, resulting in advanced or delayed dental age (DA). The purpose of this systematic review was to investigate the association between DA and different types of malocclusions.

METHODS

The search was carried out on PubMed, Scopus, Web of Science, Virtual Health Library, and in the gray literature. Observational studies that evaluated the association between DA and sagittal, vertical, or transversal malocclusions were included. The quality assessment was performed using the Newcastle-Ottawa Scale (NOS). The data from primary studies were narratively synthesized. The certainty of evidence was evaluated using the GRADE approach. The study was conducted from August 2023 to October 2023.

RESULTS

One Thousand Nine Hundred Ninety-One records were identified in the initial search. Twenty (n = 20) studies were included. Most of the studies (n=15) presented a moderate quality according to NOS. Twelve studies evaluated the association between DA and sagittal discrepancies; eight studies evaluated vertical discrepancies, and only one study analyzed a transversal discrepancy. Demirjian's method for DA assessment was the most used among the studies. The primary studies observed that patients of both sexes presenting a vertical growth pattern and males with skeletal Class III malocclusion tend to have advanced DA. The study that investigated transversal malocclusion found that unilateral posterior cross-bite is associated with delayed DA. The certainty of evidence was very low for all outcomes evaluated.

CONCLUSION

DA may be associated with the type of malocclusion. It is suggested that DA can be used as an initial diagnostic tool in orthodontics. Future well-designed studies should be performed in order to investigate the association between DA and different types of malocclusions in more detail.

TRIAL REGISTRATION

This study was registered in the PROSPERO database (CRD42023454207).

Evidence of Age Estimation Procedures in Forensic Dentistry: Results from an Umbrella Review

Background and objective: Age estimation is an important tool when dealing with human remains or undocumented minors. Although the skull, the skeleton or the hand-wrist are used in age estimation as maturity indicators, they often present a lack of good conditions for a correct identification or estimation. Few systematic reviews (SRs) have been recently published; therefore, this umbrella review critically assesses their level of evidence and provides a general, comprehensive view. Materials and methods: Considering the review question "What is the current evidence on age determination approaches in Forensic Dentistry?" an electronic database search was conducted in four databases (PubMed, Cochrane, WoS, LILACS) up to December 2022, focusing on SRs of age estimation through forensic dentistry procedures. The methodological quality was analyzed using the measurement tool to assess SRs criteria (AMSTAR2). Results: Eighteen SRs were included: five of critically low quality, six of low quality, three of moderate quality and four of high quality. The SRs posited that Willems' method is more accurate and less prone to overestimation; most methods seem to be geographically sensitive; and 3D-imaging and artificial intelligence tools demonstrate high potential. Conclusions: The quality of evidence on age estimation using dental approaches was rated as low to moderate. Well-designed clinical trials and high-standard systematic reviews are essential to corroborate the accuracy of the different procedures for age estimation in forensic dentistry.

Effect of impaction on third molar development and age estimation-A study in a Lebanese population

BACKGROUND

The effect of impaction on third molar development is disputable as the scientific literature is not uniform. In parallel, population-specific studies have been encouraged in dental age estimation. This study aimed to investigate the effect of impaction on third molar formation in a sample of Lebanese individuals.

MATERIALS AND METHODS

The sample consisted of 518 panoramic radiographs of females (n=229) and males (n=289) between 15 and 23.9 years. Mandibular third molars were classified based on their position as non-impacted and impacted (with horizontal, vertical, mesioangular, and distoangular impaction). Dental development was classified according to Demirjian's 8-level staging system.

RESULTS

Most teeth presented mesioangular impaction (#38=29.7%, #48=33%). Developing third molars were predominantly distributed between stages D and G. The mean age of most developmental stages was higher among impacted teeth, meaning that third molar mineralization could be slower in the presence of impaction. In general, the delayed dental development did not have statistically significant effects (P<0.05). However, descriptive data pointed out differences between (impacted and non-impacted) mean ages of >12 months-suggesting a potential clinical significance (despite the lack of a statistical one). Furthermore, differences changed based on sex and side (#38/#48).

CONCLUSION

Therefore, dental age estimation from third molars in the selected Lebanese population should preferably be performed in non-impacted third molars whenever available.

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

BACKGROUND

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.

METHODOLOGY

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.

RESULTS

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.

CONCLUSION

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.

Radiographic dental age estimation applying and comparing Demirjian's seven (1973) and four (1976) teeth methods

To apply Demirjian's seven (1973, D7) and four (1976, D4) teeth methods in a sample of Brazilian children and compare their performances for age estimation. Panoramic radiographs of 1200 children (600 females and 600 males) were collected from Southeast Brazil. The children were equally distributed (n = 60 females and 60 males) between age intervals of 1 year between 6 and 15.9 (mean age = 10.9; standard deviation [SD]: 2.9) years. D7 and D4 dental age estimation methods were applied by two observers and were compared based on their error rates (error = estimated age-chronological age). Both methods overestimated the chronological age (p < 0.0001). D7 led to overestimations of 0.71 (p < 0.0001) in females and 0.83 (p < 0.0001) in males, while the overestimations with D4 were 0.14 (p = 0.0067) and 0.73 (p < 0.0001) for females and males, respectively. The mean age estimated by D7 was 11.7 (SD: 3.1) years, while for D4, it was 11.3 (SD: 3.3) years. Intra- and interobserver agreement was ≥ 0.98. D4 optimized the performance of radiographic dental age estimation compared to D7. Improvements were reflected in the total sample and separately for female and male children from Southeast Brazil.

How old are you? A systematic review investigating the relationship between age and mandibular third molar maturity

INTRODUCTION AND OBJECTIVE

Radiographic evaluation of the maturity of mandibular third molars is a common method used for age estimation of adolescents and young adults. The aim of this systematic review was to examine the scientific base for the relationship between a fully matured mandibular third molar based on Demirjian's method and chronological age, in order to assess whether an individual is above or below the age of 18 years.

METHODS

The literature search was conducted in six databases until February 2022 for studies reporting data evaluating the tooth maturity using Demirjian´s method (specifically stage H) within populations ranging from 8 to 30 years (chronological age). Two reviewers screened the titles and abstracts identified through the search strategy independently. All studies of potential relevance according to the inclusion criteria were obtained in full text, after which they were assessed for inclusion by two independent reviewers. Any disagreement was resolved by a discussion. Two reviewers independently evaluated the risk of bias using the assessment tool QUADAS-2 and extracted the data from the studies with low or moderate risk of bias. Logistic regression was used to estimate the relationship between chronological age and proportion of subjects with a fully matured mandibular third molar (Demirjian´s tooth stage H).

RESULTS

A total of 15 studies with low or moderate risk of bias were included in the review. The studies were conducted in 13 countries and the chronological age of the investigated participants ranged from 3 to 27 years and the number of participants ranged between 208 and 5,769. Ten of the studies presented the results as mean age per Demirjian´s tooth stage H, but only five studies showed the distribution of developmental stages according to validated age. The proportion of subjects with a mandibular tooth in Demirjian´s tooth stage H at 18 years ranged from 0% to 22% among males and 0 to 16% in females. Since the studies were too heterogenous to perform a meta-analysis or a meaningful narrative review, we decided to refrain from a GRADE assessment.

CONCLUSION

The identified literature does not provide scientific evidence for the relationship between Demirjian´s stage H of a mandibular third molar and chronologic age in order to assess if an individual is under or above the age of 18 years.

Use of third molar eruption based on Gambier's criteria in assessing dental age

The biological aspects of determining the dental age of subadults represent an important interdisciplinary scientific link with applications in criminal law and in forensic anthropology and dentistry. In criminal procedural law, it is necessary to determine the exact age of an undocumented person in view of the application of the provisions on juvenile offenders and minor victims. Chronological age can be estimated from the development of the third molars, as these are the only teeth that develop at the age of 18. The aim of this study was to verify the applicability of the Gambier method based on the eruption of the third permanent molars in the mandible and maxilla, to contribute to forensic age assessment. The analyzed group that met the criteria consisted of 811 orthopantomograms (OPGs) (339 females and 472 males) between the ages of 13 and 25 years. The OPGs were retrospectively analyzed according to the method of Gambier et al. (Int J Legal Med 133:625-632, 29), which refers to the eruption stages of the third molar. Differences between eruption stages of maxillary and mandibular third molars were statistically significant in both biological sexes. Intersexual differences in mean age were significant only at stage 3 for any M3 tooth and at stage 1 for mandibular M3. There were no statistically significant differences between the left and right mandibular and maxillary third molars, respectively. Differences between mandibular and maxillary M3 were significant only for stage 1 in males on the left side and for stage 2 in both sexes and sides. The method used allowed the best classification of individuals into minor and adult groups (based on phase D-90.41% of individuals, based on the third stage of the mandibular left third molar-86.29%). Based on the results obtained, we can assume that the method cannot be used alone in the initial examination of living individuals, since all four third molars must be assessed and there are no additional findings from practice.

Sex and age determination of human mandible using anthropological parameters and TCI and Kvaal methods: study of a Serbian medieval sample

PURPOSE

The aim of the study was to test the efficacy, reliability, and applicability of the Kvaal and Tooth Coronal Index (TCI) age determination techniques, and then to compare them with each other, as well as with the conventional anthropological age and sex determination techniques.

METHODS

The analyzed material originates from the medieval necropolis of the Vinča-Belo brdo site. During the research, 60 periapical (PA) and 30 orthopantomographic (OPT) images were analyzed. On each analyzed tooth, age assessment was performed using both TCI and Kvaal techniques. The obtained values of dental estimated age were compared with age estimated by anthropological analysis, and the deviations between the estimated and chronological age were analyzed in relation to the assessment technique, type of dental radiograph, tooth group, sex, and age.

RESULTS

The mean error between TCI and the osteological method was 8.44 (SD = 7.56, Min = 0.169, Max = 36.4) and between Kvaal and the osteological method was 7.71 (SD = 5.57, Min = 0.133, Max = 26.7). The average value of age recorded by TCI method was 32.5 years and by Kvaal method was 34.7 years. There was no statistically significant difference based on the two radiographic methods, gender, individual teeth, or tooth group pairs. There was a statistically significant positive correlation between age and the error present.

CONCLUSION

Gender determination based only on the mandible has a high correlation with the anthropological gender determination. The Kvaal method and the TCI method have proven their efficiency, reliability, and applicability. Significant correlation has been observed between dental and anthropological age and sex determination methods.

Validity of age estimation methods and reproducibility of bone/dental maturity indices for chronological age estimation: a systematic review and meta-analysis of validation studies

Several approaches have been developed to estimate age, an important aspect of forensics and orthodontics, using different measures and radiological examinations. Here, through meta-analysis, we determined the validity of age estimation methods and reproducibility of bone/dental maturity indices used for age estimation. The PubMed and Google Scholar databases were searched to December 31, 2021 for human cross-sectional studies meeting pre-defined PICOS criteria that simultaneously assessed the reproducibility and validity. Meta-estimates of validity (mean error: estimated age-chronological age) and intra- and inter-observer reproducibility (Cohen's kappa, intraclass correlation coefficient) and their predictive intervals (PI) were calculated using mixed-effect models when heterogeneity was high (I2 > 50%). The literature search identified 433 studies, and 23 met the inclusion criteria. The mean error meta-estimate (mixed effects model) was 0.08 years (95% CI - 0.12; 0.29) in males and 0.09 (95% CI - 0.12; 0.30) in females. The PI of each method spanned zero; of nine reported estimation methods, Cameriere's had the smallest (- 0.82; 0.47) and Haavikko's the largest (- 7.24; 4.57) PI. The reproducibility meta-estimate (fixed effects model) was 0.98 (95% CI 0.97; 1.00) for intra- and 0.99 (95% CI 0.98; 1.00) for inter-observer agreement. All methods were valid but with different levels of precision. The intra- and inter-observer reproducibility was high and homogeneous across studies.

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

Background

The 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.

Methods

A 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).

Results

The 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.

Conclusions

This 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.

A large sample-sized study on dental development of children treated at the Central Dental Clinic (OCEx) of the Brazilian Army

OBJECTIVES

To test and compare the performance of two radiographic methods for dental age estimation on a large sample of Brazilian boys and girls.

MATERIAL AND METHODS

The sample consisted of 1.990 panoramic radiographs of Brazilian children (age: 3-15.9 years) equally balanced based on sex. The sample was distributed into ten age categories, each with up to 200 children. Age estimation was performed with Willems' (2001) and Demirjian's (1973) methods. Estimated (EA) and chronological (CA) ages were compared. The performances of the methods were quantified based on sex and age category.

RESULTS

The overall differences between CA and EA for Willems' method in boys and girls were 0.06 and - 0.02, respectively. For Demirjian's method, the differences were 0.60 and 0.74, respectively. The overestimations of Demirjian's method were statistically significant (p < 0.001). Willems' method reached the best outcomes among children between 3 and 12 years, while Demirjian's best performances were between the ages of 7 and 10 years.

CONCLUSION

Willems' method led to differences between CA and AE that were acceptable for clinical and forensic practice.

CLINICAL RELEVANCE

Age estimation may guide clinical decisions based on treatment timing. Validating international tools is necessary to promote evidence-based practice and country-specific application. This study overcame the limitations of previous research to provide a more realistic perspective of the performance of age estimation methods in Brazilian children. Willems' method had a superior performance compared to Demirjian's method and led to outcomes that were better than most studies with the Brazilian population.

Estimation of dental age based on the developmental stages of permanent teeth in Japanese children and adolescents

Assessment of children’s growth and development based on general and oral developmental status and dental age is important in pediatric dentistry for appropriate diagnosis and treatment. Teeth are a useful maturation index because they are unlikely to be affected by exogenous factors such as disease. We examined the correlation between chronological and dental age of permanent teeth in Japanese children and adolescents using orthopantomography. The sample comprised 1024 orthopantomographs from individuals aged 3–18 years, which were stored in an electronic media database for 10 years (2009–2019). We classified the developmental stages of each permanent tooth were classified into 11 stages, clarified the dental age for each developmental stage, and prepared a conversion table. Using the results, we compared the sequence and rate of development of each permanent tooth. We clarified the dental age of each permanent tooth from childhood to mid-adolescence and established a method for calculating the dental age of the whole jaw that is appropriate for modern Japanese individuals. We found that girls tended to form teeth at a faster rate than boys until puberty, but boys caught up with girls after puberty, suggesting that secondary sexual characteristics are involved in the rate of tooth formation.

Applicability of Willems method for age estimation in Brazilian children: performance of multiple linear regression and artificial neural network

Background

Dental age estimation of children may be necessary in the clinical and forensic fields. In the former, it may contribute to the investigation of dental development and biological maturation. In the latter, dental age estimation may support the Court in several circumstances, such as adoption and unidentified bodies of deceased children. This study aimed to apply Willems method for dental age estimation of children from Southeastern Brazil. The second aim of the study was to test the performance of the method modeled with multiple linear regression (MLR) and artificial neural network (ANN). The sample consisted of 1000 panoramic radiographs of female (n = 500) and male (n = 500) Brazilian children. The individuals were evenly distributed through ten age intervals of 1 year from 6 to 15.99 years. Dental development was classified with the 7-teeth technique of Demirjian et al. (1973), followed by age calculation with Willems method (2001). The difference between chronological and estimated ages was quantified for the original Willems model and for the MLR and ANN models.

Results

For females and males, the overall difference found with Willems original model was 0.27 and 0.28, respectively. With MLR and ANN, the overall differences were 0.54 and 0.35, and 0.26 and 0.24, respectively. The ANN was able to reduce half of the mean error of female age predictions up to 100%. The same phenomenon occurred in 1/3 of the males. Despite the improvements of the ANN model to specific age groups, the original Willems model performed similar or better in 40% of the studied age intervals. All the models showed the worse age predictions in the interval between 15 and 15.99 years (p < 0.001).

Conclusions

Willems method remains optimal and applicable after 20 years since original development. The ANN model might be an option for future improvements (depending on sex and age interval).

Accuracy of the Demirjian's method for assessing the age in children, from 1973 to 2020. A meta-analysis

One of the most common ways to assess the age in subadults using dental records is the Demirjian method. As the number of the studies using this method increased significantly in the recent years, and as their results were often conflicting, we investigated the accuracy of the method. We performed a systematic review and meta-analysis of observational studies obtained from Pubmed, using a random-effects model with the DerSimonian-Laird estimator, and raw mean difference for effect size measure. Prediction intervals (at 95%) were used to assess the presence of significant statistical differences between chronological and dental age. Our meta-analysis showed that Demirijan's method overestimated dental age by 0.48 years in girls and 0.51 in boys. Depending on the location and sex, in girls the smallest average overestimation was found in Asia (except India), with a value of 0.36 years, and the largest overestimation in Turkey/Arabia, with a value of 0.66 years. In boys, the smallest average overestimation was found in India (0.45 years), but Asia (except India), Africa - both with 0.46 years and Oceania - with 0.47 years were close, while the largest overestimation was found in Turkey/Arabia, with an average value of 0.63 years. The Demirjian method overestimated the age by about half a year for both sexes. Even if there are some geographical/ethnic differences, they are rather small, making the method useful irrespective of the ethnic profile of the subjects.

Dental age estimation in children that have undergone antineoplastic treatment

OBJECTIVE

Even though many studies have been performed to estimate DA in general population, limited research has been performed concerning medical compromised populations such as childhood cancer survivors. The aims of this case-control study were (a) to estimate dental age in a population of children that have undergone antineoplastic treatment with three different methods and (b) to compare it with the estimates from healthy subjects (control group).

MATERIALS AND METHODS

Seventy-three oncology patients and equal number of healthy control subjects from the Pediatric dentistry Department had their dental age estimated through recent orthopantograms using Dermijian's, Willems' and London Atlas methods. All OPGs randomly assessed by two calibrated observers. Mean age difference was calculated. Intraclass Correlation Coefficient was used to assess intra-observer reliability and the Concordance Correlation Coefficient used to assess inter-observer reliability.

RESULTS

Concerning the CCS group 35 subjects (48%) were males and 38 (52%) were females, with an overall mean chronological age 10.95 years, ranging between 5.37 and 15.83 years. Intra- and inter-examiner reliability was exceptional for all methods. Mean DA differences in both groups and were not statistically sinificant regardless of the method used. The marginally lower values when males and females were investigated separately is basically due to the corresponding reduction of the sample size.

CONCLUSION

An overestimation of DA observed in both groups by all methods was not significant. All three methods produced highly accurate comparable results when it comes to estimate the actual chronological age in both groups (CCS and control subjects) regardless of gender.

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.

Assessment of maturation indicators in individuals with different skeletal malocclusion

PURPOSE

The aim of this study was to comparatively evaluate hand-wrist bones, cervical vertebrae and tooth development stages according to skeletal classification.

METHODS

The orthodontic initial records of 297 patients were used and separated into three groups according to the skeletal malocclusion. Three groups including 99 people each were sampled representing malocclusions with Angle classes I, II and III, respectively. The panoramic, cephalometric and hand-wrist radiographs of all patients included in this study were used to compare dental and skeletal maturation indicators. Calcification of teeth was rated according to the system of Demirjian. To evaluate the stage of skeletal maturation hand-wrist radiographs were analyzed according to the Grave and Brown method. Also, Hassel and the Farman method was used to classifying vertebral developmental stages. Spearman rank correlation tests, as well as Fisher exact χ² tests with r×c tables, were used for the comparison of categorical variables.

RESULTS

Hand-wrist, vertebral and dental development stages showed a statistically significant relationship (p < 0.01) for both genders and in all malocclusions. The association between the different maturation indicators used in this study and the type of malocclusion was also statistically significant for both genders. It was observed that the peak period of skeletal maturation according to the hand-wrist radiograph findings correlated with the cervical vertebrae stage C3 in girls (63.2%) and C2-C3 in boys (43.5-43.5%). The weakest correlation was seen between the dental development stages and the skeletal developmental stages in the class II group (r = 0.443-0.220 [girls]; r = 0.604-0.410 [boys]).

CONCLUSION

The use of the dental development stage as a reliable indicator of maturation was limited. According to the Demirjian method, the calcification stage of the second molar might indicate that the individual is in the pubertal peak period.

Assessment of dental age estimation methods applied to Brazilian children: a systematic review and meta-analysis

OBJECTIVES

To review the scientific literature of studies on dental age estimation methods applied to Brazilian children.

METHODS

A systematic literature review was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in PROSPERO (CRD42020136170). Six scientific databases were used as primary search sources (PubMed, Scopus, LILACS, SciELO, Embase and Web of Science) and two databases (Open Grey and Open Thesis) were searched to partially select the "grey literature." Only cross-sectional studies were included. The risk of bias was assessed by means of Joanna Briggs Institute Critical Appraisal Tools for Systematic Reviews. The standardized mean difference (SMD) between the estimated dental and chronological ages was meta-analysed via random effects model.

RESULTS

The search resulted in 2,527 studies, from which 13 met the eligibility criteria. Out of the eligible studies, 76.92% had low risk of bias and high methodological quality. Ten studies provided proper information to be included in the meta-analysis.The methods and their SMD between estimated and chronological ages were: Willems'=0.05, Lilequist and Lundberg's = -0.11, Nolla's = 0.22, Mornstad's = 0.27, Cameriere's = -0.31, Demirjian's = 0.74 and Haavikko's = -0.87.

CONCLUSION

Although originally trained in populations worldwide, most of the international methods for radiographical dental age estimation had optimal performance in Brazilian children.

A modified dental age assessment method for 5- to 16-year-old eastern Chinese children

Objectives

Age estimation is widely applied in the field of orthodontics, pediatric dentistry, and forensic science. Dental age estimation by the radiological method is frequently used because of its convenience and noninvasiveness. However, there are not enough suitable methods for eastern Chinese children. This study aimed to establish a modified formula for eastern Chinese children according to the Demirjian method and then compared the accuracy of the modified method with the Demirjian method and Willems method.

Materials and methods

A total of 2367 dental panoramic radiographs from individuals aged 5–16 years of eastern China were collected as samples. Age estimation was conducted using the Demirjian and Willems methods. The polynomial curve fitting method was used to modify the Demirjian method to improve its application to the eastern Chinese children. The paired t test and accuracy ratio were used to compare the applicability of the modified methods with two commonly used methods.

Results

The mean chronological age (CA) of the subjects was 11.20 ± 3.29 years for boys and 10.99 ± 3.12 years for girls. The mean difference values between the CA and dental age (DA) (CA–DA) using the Demirjian and Willems methods were 0.73 and 0.7 for boys, respectively, and both 0.79 for girls. The modified method using the polynomial curve fitting presented a smaller underestimation compared with CA for both boys (0.04 years) and girls (0.09 years), which showed a high suitability to Chinese children to some extent.

Conclusions

The Willems method was more accurate in estimating DA compared with the Demirjian method. However, the modified method was more accurate than the two methods; therefore, it can be used in eastern Chinese children.

Clinical relevance

It was thought to be a non-invasive, convenient, and efficient method to connect DA and CA. By estimating dental age, pediatrist, and orthodontists can better understand the development of permanent teeth and provide a more accurate orthodontic treatment time and treatment plan to children patients.

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.

Application of Cameriere's method for dental age estimation in children in South China

The aim of this study was to evaluate the applicability of Cameriere’s European formula for age estimation in children in South China and to adapt the formula to establish a more suitable formula for these children. Moreover, the performance of dental age estimation based on Cameriere’s method combining the developmental information of permanent teeth (PT) and third molar (TM) was also analysed. Orthopantomographs of 720 healthy children in Group A, and orthopantomographs of 320 children and 280 subadults in Group B were assessed. The samples of Group A were divided into training dataset 1 and test dataset 1, and the samples of Group B were also divided into training dataset 2 and test dataset 2. A South China-specific formula was established based on the training dataset 1, and the comparison of accuracy between the Cameriere’s European formula and the South China-specific formula was conducted with the test dataset 1. Additionally, a PT regression model, a TM regression model, and a combined regression model (PT + TM) were established based on the training dataset 2, and the performance of these three models were validated on the test dataset 2. The Cameriere’s European formula underestimated chronological age with a mean difference (ME) of −0.47 ± 1.11 years in males and −0.69 ± 1.19 years in females. However, the South China-specific formula underestimated chronological age, with a mean difference (ME) of −0.02 ± 0.71 years in males and −0.14 ± 0.73 years in females. Compared with PT model and TM model, the PT and TM combined model obtained the smallest root mean square error (RMSE) of 1.29 years in males and 0.93 years in females. In conclusion, the South China-specific formula was more suitable for assessing the dental age of children in South China, and the PT and TM combined model can improve the accuracy of dental age estimation in children.

Key points

Orthopantomographs of 720 healthy children in Group A, and orthopantomographs of 320 children and 280 subadults in Group B were assessed.

A South China-specific formula was established based on the training dataset 1, and the comparison of accuracy between the Cameriere’s European formula and the South China-specific formula was conducted with the test dataset 1.

A PT regression model, a TM regression model, and a combined regression model (PT + TM) were established based on the training dataset 2, and the performance of these three models were validated on the test dataset 2.

The South China-specific formula was more suitable for assessing the dental age of children in South China, and the PT and TM combined model can improve the accuracy of dental age estimation in children.

Dental development in patients with and without unilateral cleft lip and palate (UCLP): a case control study

OBJECTIVE

To evaluate if the presence of unilateral cleft lip and palate (UCLP) causes delay in dental age and tooth development.

MATERIALS AND METHODS

Panoramic radiographs of 189 non-syndromic UCLP patients, aged from 6 to 20 years, were collected. Two measures of tooth development were examined: dental maturity scale for the seven left mandibular teeth (dental age-DA) and the degree of each tooth development (developmental score-DS). All the teeth except third molars were staged according to the Demirjian's method. The data of the cleft group were compared with a control group matched for age and gender, based on the findings observed in other 189 panoramic radiographs.

RESULTS

At all ages, DA was lower in the UCLP group, but not always significantly; the highest difference was - 1.411 for females at 13 years old and - 0.776 for males at 12 years old. DS of all teeth was significantly lower in the UCLP group, at all ages under 17 in females, and at all ages under 18 in males. In UCLP group, tooth development was more delayed in the maxilla compared with the mandible. No evidence of a slower development at the cleft side compared with the non-cleft side was highlighted.

CONCLUSIONS

Significant lower dental development was observed in UCLP patients compared with control ones by using DS and DA indexes.

CLINICAL RELEVANCE

These findings can help the clinicians in establishing a proper orthodontic and surgical diagnosis and treatment planning in UCLP patients and for forensic age estimation's purposes.

Accuracy assessment of dental age estimation with the Willems, Demirjian and Nolla methods in Spanish children: Comparative cross-sectional study

Background

The objective of this study was to evaluate and compare the validity and accuracy of the Willems, Demirjian and Nolla methods in predicting chronological age in a Spanish ethnicity population.

Methods

A sample of 604 orthopantomographs of Spanish children aged 4 to 13 years was evaluated by two independent evaluators. Descriptive statistics were applied to calculate the chronological age and dental age, presenting the mean and standard deviation. The difference between dental age and chronological age was calculated for each method. A positive result indicated an overestimation and a negative figure indicated an underestimation. The Wilcoxon test for paired data and Spearman’s correlation coefficient were applied by age groups and sex to compare the chronological age and dental age of each method (that of Willems, Demirjian and Nolla). Statistical tests were performed at a 95% confidence level.

Results

The interexaminer agreement was 0.98 (p = 0.00), and the intraexaminer agreement was 0.99 (p = 0.00). The Willems method significantly overestimated the age of boys (0.35 years (0.93)) and girls (0.17 years (0.88)). The Demirjian method significantly overestimated the age of boys (0.68 years (0.95)) and girls (0.73 years (0.94)). The Nolla method significantly underestimated age in boys (0.44 years (0.93)) and girls (0.82 years (0.98)).

Conclusions

In the Spanish population, the use of the Demirjian method for legal and medical purposes is frequent. This study reveals that the Willems method is more appropriate due to its greater precision in estimating dental age.

Applicability of 2 Dental Age Estimation Methods to Taiwanese Population

The aim of this study is to assess the accuracy of Demirjian and Willems dental age estimation methods on a population of 8- to 15-year-old Taiwanese children. A total of 799 digital panoramic radiographs (404 boys, 395 girls) of children aged from 8.00 to 15.99 years are evaluated. All panoramic films are assessed by 2 examiners using Demirjian and Willems methods. We randomly select 48 panoramic films to evaluate the reproducibility of dental age measurements. The intraobserver and interobserver Cohen's kappa values are 0.733 and 0.762, respectively.The difference between chronological age and dental age is calculated for each individual using both methods. The result shows that Demirjian method slightly overestimates the chronological age of children. The mean age difference is 0.12 years for boys (standard deviation [SD], 0.80) and 0.21 years for girls (SD, 0.95). Willems method slightly underestimates the chronological age of children. The mean age difference is -0.22 years for boys (SD, 0.80) and -0.12 years for girls (SD, 0.92).In conclusion, Demirjian and Willems methods are both accurate for assessing dental age in the Taiwan region of China. The mean age differences of both methods are within ±1 year, which is acceptable at forensic odontology level. However, although the discrepancy between chronological age and dental age is frequently observed between -0.5 and 0.5 years in both methods, there is no guarantee it will be accurate for any particular individual, further modifications to both methods are suggested.

Applicability of Demirjian's method for dental age estimation in a group of Egyptian children

Aims

The aims of this study were to evaluate the applicability of Demirjian’s method for dental age assessment in a group of Egyptian children in Minia city and to develop an age predictive equation suitable for the studied group.

Subjects and methods

In this retrospective, blind, cross-sectional study, 160 dental panoramic radiographs (DPTs) were selected from 420 DPTs from healthy children aged between three and 10 years old from the archived medical files of patients attending Minia University Dental Hospital (MUDH) and evaluated to estimate dental ages.

Results

Age was overestimated for almost all of the studied subjects with an accuracy range from 0.18 to 1.19 years for males and from 0.08 to 0.87 years for females, with the exception of two age subgroups (9–10-year-old males and 10–11-year-old females, for which the mean difference values were −0.06 and −0.008 years, respectively). A Logistic regression was used to generate a suggested formula for dental age estimation.

Conclusions

Demirjian’s method may be unsuitable for Egyptian children living in Minia city. Development of a predication equation and the introduction of adaptable conversion tables to transform the maturity score into a dental age for Egyptian children may be suitable alternatives. The validity of the newly developed prediction equation must be tested among all Egyptian children.