Technical note: RP Atlas-an unprecedented proposal for a Brazilian population dental development chart based on the London atlas

Age estimation methods through developmental atlases are simplified by image comparison using radiographs. Atlas-based methods have been utilized to create population-specific charts addressing population diversity. To tackle the absence of a dedicated atlas for the Brazilian population, the objective of the present study was to create a new atlas for dental development in Brazil based on the London Atlas chart. The new atlas (RP Atlas) is based on the median of tooth development, eruption, and resorption in individuals aged 5 to 23. The sample (567 individuals) was divided between females (n = 290) and males (n = 277). The RP Atlas was handcrafted, scanned, colored, and clustered in two atlases divided by sex. The development of a specific atlas for the Brazilian population has the potential to enhance the accuracy of age estimation in forensic scenarios, notably in a mixed country like Brazil. Further research is needed to assess the suitability of the newly developed atlas for the Brazilian population.

Machine learning assessment of dental age classification based on cone-beam CT images: a different approach

OBJECTIVES

Machine learning (ML) algorithms are a portion of artificial intelligence that may be used to create more accurate algorithmic procedures for estimating an individual's dental age or defining an age classification. This study aims to use ML algorithms to evaluate the efficacy of pulp/tooth area ratio (PTR) in cone-beam CT (CBCT) images to predict dental age classification in adults.

METHODS

CBCT images of 236 Turkish individuals (121 males and 115 females) from 18 to 70 years of age were included. PTRs were calculated for six teeth in each individual, and a total of 1416 PTRs encompassed the study dataset. Support vector machine, classification and regression tree, and random forest (RF) models for dental age classification were employed. The accuracy of these techniques was compared. To facilitate this evaluation process, the available data were partitioned into training and test datasets, maintaining a proportion of 70% for training and 30% for testing across the spectrum of ML algorithms employed. The correct classification performances of the trained models were evaluated.

RESULTS

The models' performances were found to be low. The models' highest accuracy and confidence intervals were found to belong to the RF algorithm.

CONCLUSIONS

According to our results, models were found to be low in performance but were considered as a different approach. We suggest examining the different parameters derived from different measuring techniques in the data obtained from CBCT images in order to develop ML algorithms for age classification in forensic situations.

Comparison of Demirjian's comprehensive chart with the London atlas of tooth development in children and adolescents: a pilot study

Dental age estimation has its application in various subdisciplines of medicine and dentistry. New methods of dental age (DA) estimation are emerging and it is important that we compare different methods to determine which one is more closely related to the chronological age. Demirjian's method is one of the most widely used techniques and has been tested in various ethnic populations globally. In 2016, another approach to DA estimation is the London atlas of human tooth development and eruption. No study has compared Demirjian's comprehensive chart and London atlas method in the Indian population. Hence, in the current study, we estimated DA using Demirjian's comprehensive chart and London atlas method for association with the known chronologic age in children and adolescent population. The study also attempted to determine if sexual dimorphism existed in DA estimated by the two methods. Estimation was performed for both methods on 100 orthopantomogram records (50 males and 50 females, aged 6-16 years) of orthodontic patients. The data were compared and analysed using paired t-tests. There was an overestimation of DA by Demirjian's comprehensive chart on an average of +1.3 years in males and +0.5 years in females, whereas using London atlas, it was +1.4 years in males and +0.5 years in females. The mean of underestimation was -0.6 years in males and -0.8 years in females using Demirjian's comprehensive chart, whereas it was -0.8 years in males and -0.5 years in females. A statistically significant difference (P < 0.0001) was found when mean chronological age (11.6 ± 2.6) years of the participants was compared with DA estimated using either Demirjian's comprehensive chart (12.3 ± 2.8) years or London atlas (11.8 ± 2.9) years. The trends in this pilot study point towards more accuracy of London atlas over Demirjian's method when done using comprehensive chart for estimating DA. In summary, the results of the current pilot study indicates greater accuracy of London atlas method over Demirjian's comprehensive chart method for estimating DA in Indian population. This finding should be validated by conducting similar studies using larger sample, on diverse Indian ethnic populations, for applicability in pedodontic, orthodontic, and forensic domains.

Key points

No study has compared Demirjian's comprehensive chart and London atlas method in the Indian population.The dental age estimated by London method was closer to chronological age as compared to Demirjian's method in our study sample.Significant difference was found in chronological age and estimated age using London atlas method in both males and females.

Relationship between the Height of Alveolar Bone Resorption and Sex and Age in Adolescents

OBJECTIVES

To explore the relationship between the height of alveolar bone resorption and sex and age in the adolescent dentition.

METHODS

Multi-slice computed tomography (MSCT) was used to measure the height of alveolar bone resorption at labial, lingual, mesial and distal sites of teeth in 149 adolescents aged from 10 to 20 years. SPSS 25.0 software was used to analyze the relationship between the height of alveolar bone resorption and sex and age.

RESULTS

There was no significant difference in the height of alveolar bone resorption between sex (P>0.05). The height of alveolar bone resorption was positively correlated with age in all types of teeth. The model constructed by combining the alveolar bone resorption height data of four sites (y=2.569x₁+3.106x₂+4.108x₃+1.451x₄-0.082, R²_max=0.756)had a better ability to infer age than that of combining two sites (y=5.942x₁+4.489x₂+0.612, R²_max=0.706) and a single site (R²_max=0.638).

CONCLUSIONS

The height of alveolar bone resorption is positively correlated with the age of adolescents. The combination of four sites has a stronger ability to infer the relationship between the height of alveolar bone resorption and age in adolescents and has higher accuracy in practical application.

[Accuracy of the Cameriere's method and its variant the European Formula for age estimation in subadult peruvian population]

Objective

To determine the accuracy of the Cameriere method and its variant, the European Formula, in a sub-adult Peruvian population; and determine a chronological age predictor equation.

Materials and methods

Descriptive, observational, cross-sectional and retrospective study. It was used 257 digital panoramic radiographs of patients in mixed dentition from 5 to 12 years of age belonging to the "Dental Cientifica" Dental Center of the Universidad Cientifica del Sur in the city of Lima, Peru. All morphological variables and gender of the subjects were used as predictor variables for age estimation. To evaluate the accuracy of each estimation method, the age of each individual was compared with the estimated age using the mean prediction error. Multiple linear regression was used to generate the predictive equation for chronological age.

Results

It was found that the mean prediction error between the chronological age with respect to the age estimated by the Cameriere method Formula and the European Formula was 0.73±0.55 years and 0.77±0.57 years, respectively. A model was generated whose predictor variables for age were s and N0, both variables were statistically significant and the Adjusted R2 for the number of variables was 75.96%.

Conclusion

It was determined that Cameriere's Formula was more accurate than the European Formula; however, there was no statistically significant difference between the two. Additionally, it was possible to establish a specific linear regression formula for a Peruvian population aged 5 to 12 years with an adequate predictive capacity.

Use of the Demirjian method to estimate dental age in panoramic radiographs of patients treated at the Buenos Aires University School of Dentistry

The aim of this study was to determine the difference between real age (RA) and dental age (DA) in boys and girls from the Autonomous City of Buenos Aires (C.A.B.A.) by analyzing digital panoramic radiographs from the database of the Imaging Department at the Buenos Aires University School of Dentistry, using the Demirjian Method (DM). The sample consisted of 508 panoramic radiographs of 6- to 14-year old Argentines (268 female and 240 male). The Demirjian method was used to estimate dental age from each panoramic radiograph, and the Wilcoxon test was applied to perform a comparative analysis with the real age recorded in the image database. Average RA was 9.36 years (SD 2.11), and average DA according to the Demirjian method was 10.45 years (SD 2.31). For females, RA was 9.25 (SD 2.12), and DA according to the DM was 10.40 years (SD 2.41). For males, RA was 9.46 (SD 2.10), and DA according to the DM was 10.50 years (SD 2.22). An inter-classcorrelationcoefficient(ICC) calculated as a correlation measure between dental age and real age was ICC = 1.09%. The ICC was 1.04% for the males and 1.15% for females. Significant differences were found between DA and RA (p<0.01) in general and according to sex. Real age was found to be lower than dental age in the study population from Buenos Aires City.

The use of dental radiographs for age estimation of unaccompanied migrant minors: Scientific and ethical concerns

Unaccompanied migrant minors are increasingly seeking asylum status in the United States (U.S.) where guidelines for age assessment call for the use of multiple forms of evidence. A commonly used approach in the U.S. is dental radiographs to assess the root development of third molars. Not only has research shown this methodology to be unreliable and imprecise, but the evidence has shown significant variability in dental development by chronologic age, race/ethnicity, sex, socioeconomic status, systemic disease, nutritional health, and other environmental factors. Misclassification of minors as adults based upon the imprecise tool of dental age assessment can have serious and harmful consequences. In the U.S., this misclassification has resulted in the housing of minors with adults in Immigrant and Custom Enforcement (ICE) operated jails. In addition, there are significant ethical concerns with regard to the use of radiographs for purposes that are neither diagnostic nor therapeutic and the lack of informed consent. In this commentary we review the (1) inadequacy of dental radiographs as a means of chronologic age assessment for minors, and (2) the ethical implications of implementing this flawed and inappropriate assessment on a highly vulnerable population.

Age and sex estimation based on pulp cavity volume using cone beam computed tomography: development and validation of formulas in a Brazilian sample

OBJECTIVES

To develop and validate formulas for age and sex estimation based on the pulp cavity volume of teeth using cone beam CT.

METHODS

The sample was composed of 116 cone beam CT scans from Brazilian individuals of both sexes, ranging in age from 13 to 70 years. A total of 232 teeth (upper central incisors and canines) were evaluated. Two calibrated examiners determined pulp cavity volumes using the ITK-SNAP software. Pearson's correlation test was used to assess the correlation between chronological age and pulp volume. Linear and logistic regression models were developed for age and sex estimation, respectively, and were validated in another sample of 72 teeth.

RESULTS

Pearson's correlation coefficients between age and pulp volume were negative and significant (p < 0.0001) for both teeth (r = -0.8782 for central incisors and r = -0.8738 for canines). The age estimation formulas showed good determination coefficients (adjusted R² = 0.7614 to 0.8367). For sex estimation, when the age was known, the coefficients were also good (adjusted R² = 0.649 to 0.812). However, when the age was unknown, the coefficients of the sex estimation formulas were low (adjusted R² = 0.047 to 0.393). Validation showed high accuracy of age estimation in individuals older than 35 years, as well as high accuracy of sex estimation when the age was known.

CONCLUSIONS

Our formulas provided excellent results and can be applied to the Brazilian population. The best results were observed for age estimation in females and for sex estimation when the age was known.

Differential Identification of Three Young Housefire Victims: Methods when Age Assessment Fails

Multiple fatality incidents involving more than one child of statistically same age (including twins) can be challenging from an identification standpoint. This case details an urban fire, in which four children perished. Age assessment on three of the victims utilizing maturity staging described by Moorrees, Fanning, and Hunt yielded insignificant results. However, a plot of the MFH data shows the difference between two identical twins and a third child. The twins share a similar growth pattern, whereas the other was different. Based on this graphical interpretation, the nontwin victim was positively identified through exclusion. These results were verified through statistical testing. This case demonstrates a method to repurpose age assessment data to graphically distinguish between child victims. Further, it is shown that radiographic and clinical presentation in childhood identical twins can elicit genetic versus acquired similarities and differences, which can be used for identification of individuals and exclusion of others.

A Reappraisal of Developing Deciduous Tooth Length as an Estimate of Age in Human Immature Skeletal Remains

This study provides an update on a quantitative method for immature age estimation based on postnatal deciduous mandibular tooth length. Two known sex and age skeletal collections from Western Europe were sampled (n = 97). Linear regression models for age estimated were calculated for each individual tooth, each sex, and sex combined sample using classical calibration. Prediction errors, residuals, and percentage of individuals whose real age fell within the 95% prediction interval were calculated. The teeth which develop earlier in life, the incisors and the first molar, showed the greatest precision, while the canine showed the least. This method has greater applicability to archeological skeletons or to children in developing countries than for use in North American or European forensic contexts. The method can be applied to incomplete or poorly preserved remains of unknown sex, particularly when dental radiographs are not an option or when teeth have been removed from the alveolus or crypt.

[Research Progress of Age Estimation Based on Age-related Changes of Dentin-pulp Complex]

Age estimation is a hot and difficult issue in forensic practice. Teeth are the most solid organs in human body and can be kept in vitro for a long time. With age, the secondary dentin gradually generates and the volume of pulp cavity constantly decreases. Therefore, forensic dentists proposed that age-related changes of dentin-pulp complex could be used to estimate age, which has been widely applied in forensic practice over the years. Due to the development of imaging technology, a variety of methods have been advocated by forensic dentists to detect the age-related changes of dentin-pulp complex for age estimation. However, different methods have their own advantages and limitations, forensic scientists should combine the use of different methods for improving the accuracy of age estimation according to the actual situation. This paper reviews current research of age estimation based on dentin-pulp complex, so as to provide reference for related research.

[Research Progress on Forensic Dentistry]

Forensic dentistry is an interdiscipline of forensic medicine and stomatology, which provides legal information by collecting, testing and assessing the dental evidence scientifically. In this review, the present application of forensic dentistry has been described, such as the estimation of age, sex, species, occupation and living habit, as well as the identification of individual, domestic violence or abuse, which aims to enrich and improve forensic dentistry for making it be more useful in forensic medicine even in juridical practice.

Applicability of Cameriere's and Drusini's age estimation methods to a sample of Turkish adults

OBJECTIVES

The aim of this study was to investigate the applicability of Drusini's and Cameriere's methods to a sample of Turkish people.

METHODS

Panoramic images of 200 individuals were allocated into two groups as study and test groups and examined by two observers. Tooth coronal indexes (TCI), which is the ratio between coronal pulp cavity height and crown height, were calculated in the mandibular first and second premolars and molars. Pulp/tooth area ratios (ARs) were calculated in the maxillary and mandibular canine teeth. Study group measurements were used to derive a regression model. Test group measurements were used to evaluate the accuracy of the regression model. Pearson's correlation coefficients and regression analysis were used.

RESULTS

The correlations between TCIs and age were -0.230, -0.301, -0.344 and -0.257 for mandibular first premolar, second premolar, first molar and second molar, respectively. Those for the maxillary canine (MX) and mandibular canine (MN) ARs were -0.716 and -0.514, respectively. The MX ARs were used to build the linear regression model that explained 51.2% of the total variation, with a standard error of 9.23 years. The mean error of the estimates in test group was 8 years and age of 64% of the individuals were estimated with an error of <±10 years which is acceptable in forensic age prediction.

CONCLUSIONS

The low correlation coefficients between age and TCI indicate that Drusini's method was not applicable to the estimation of age in a Turkish population. Using Cameriere's method, we derived a regression model.

Radiographic Assessment of Dental Maturation in Children With Dental Agenesis

BACKGROUND

Dental agenesis is the most common developmental anomaly in humans, frequently associated with disorders in dental development and maturation.

AIM

The purpose of this study is to determine radiographic variations in dental maturation in a group of Venezuelan children with dental agenesis.

STUDY DESIGN

1,188 panoramic radiographs, from healthy patients ages 5 to 12 years old were studied for agenesis of permanent teeth. Dental maturation was assessed by relative eruption and dental age according to Nolla, comparing children affected with dental agenesis to a stratified control group selected from the same population, excluding children with premature loss of primary teeth in the left quadrants and unclear radiographs. Descriptive analysis, and differences between means and medians (Student t test, Kruskall-Wallis p=0.05) were performed.

RESULTS

Medians for Nolla stages were similar between groups, with delay in tooth formation in the agenesis group for second molars (p<0.05) and maxillary lateral incisors and second premolars. Dental age was significantly underestimated for both groups, -0.89 (±0.78) for the control group and -1.20 (±0.95) for the study group. Tooth eruption was similar between groups.

CONCLUSION

Dental age was significantly delayed in Venezuelan children with dental agenesis, with variable significance for tooth formation of studied teeth.

Predictive values derived from lower wisdom teeth developmental stages on orthopantomograms to calculate the chronological age in adolescence and young adults as a prerequisite to obtain age-adjusted informed patient consent prior to elective surgical procedures in young patients with incomplete or mismatched personal data

Introduction: Surgical procedures require informed patient consent, which is mandatory prior to any procedure. These requirements apply in particular to elective surgical procedures. The communication with the patient about the procedure has to be comprehensive and based on mutual understanding. Furthermore, the informed consent has to take into account whether a patient is of legal age. As a result of large-scale migration, there are eventually patients planned for medical procedures, whose chronological age can't be assessed reliably by physical inspection alone. Age determination based on assessing wisdom tooth development stages can be used to help determining whether individuals involved in medical procedures are of legal age, i.e., responsible and accountable. At present, the assessment of wisdom tooth developmental stages barely allows a crude estimate of an individual's age. This study explores possibilities for more precise predictions of the age of individuals with emphasis on the legal age threshold of 18 years. Material and Methods: 1,900 dental orthopantomograms (female 938, male 962, age: 15-24 years), taken between the years 2000 and 2013 for diagnosis and treatment of diseases of the jaws, were evaluated. 1,895 orthopantomograms (female 935, male 960) of 1,804 patients (female 872, male 932) met the inclusion criteria. The archives of the Department of Diagnostic Radiology in Dentistry, University Medical Center Hamburg-Eppendorf, and of an oral and maxillofacial office in Rostock, Germany, were used to collect a sufficient number of radiographs. An effort was made to achieve almost equal distribution of age categories in this study group; 'age' was given on a particular day. The radiological criteria of lower third molar investigation were: presence and extension of periodontal space, alveolar bone loss, emergence of tooth, and stage of tooth mineralization (according to Demirjian). Univariate and multivariate general linear models were calculated. Using hierarchical multivariate analyses a formula was derived quantifying the development of the four parameters of wisdom tooth over time. This model took repeated measurements of the same persons into account and is only applicable when a person is assessed a second time. The second approach investigates a linear regression model in order to predict the age. In a third approach, a classification and regression tree (CART) was developed to derive cut-off values for the four parameters, resulting in a classification with estimates for sensitivity and specificity. Results: No statistically significant differences were found between parameters related to wisdom tooth localization (right or left side). In univariate analyses being of legal age was associated with consecutive stages of wisdom tooth development, the obliteration of the periodontal space, and tooth emergence, as well with alveolar bone loss; no association was found with tooth mineralization. Multivariate models without repeated measurements revealed imprecise estimates because of the unknown individual-related variability. The precision of these models is thus not very good, although it improves with advancing age. When calculating a CART-analysis and a receiver operating characteristics - area under the curve of 78% was achieved; when maximizing both specificity and sensitivity, a Youden's index of 47% was achieved (with 73% specificity and 74% sensitivity). Discussion: This study provides a basis to help determine whether a person is 18 years or older in individuals who are assumed to be between 15 and 24 years old. From repeated measurements, we found a linear effect of age on the four parameters in the individuals. However, this information can't be used for prognosis, because of the large intra-individual variability. Thus, although the development of the four parameters can be estimated over time, a direct conclusion with regard to age can't be drawn from the parameters without previous biographic information about a person. While a single parameter is of limited value for calculating the target age of 18 years, combining several findings, that can be determined on a standard radiography, may potentially be a more reliable diagnostic tool for estimating the target age in both sexes. However, a high degree of precision can't be achieved. The reason for persistent uncertainty lies in the wide chronological range of wisdom tooth development, which stretches from well below to above the 18th life year. The regression approach thus seems not optimal. Although sensitivity and specificity of the CART-model are moderately high, this model is still not reliable as a diagnostic tool. Our findings could have impact, e.g. on elective surgeries for young individuals with unknown biography. However, these results cannot replace social engagement, in particular thorough physical examination of patients and careful registration of their histories. Further studies on the use of this calculation method in different ethnic groups would be desirable.

A Reappraisal of Developing Permanent Tooth Length as an Estimate of Age in Human Immature Skeletal Remains

This study expands on existing juvenile age prediction models from tooth length by increasing sample size and using classical calibration. A sample of 178 individuals from two European known sex and age skeletal samples was used to calculate prediction formulae for each tooth for each sex separately and combined. Prediction errors, residuals, and percentage of individuals whose real age fell within the 95% prediction interval were calculated. An ANCOVA was used to test sex and sample differences. Tooth length for age does not differ between the samples except for the canine and second premolar, and no statistically significant sex differences were detected. The least prediction error was found in the incisors and the first molar, and the highest prediction error was found in the third molar. Age prediction formulae provided here can be easily used in a variety of contexts where tooth length is measured from any isolated tooth.

Age determination in refugee children: A narrative history tool for use in holistic age assessment

AIM

To present the rationale for using a narrative history tool as part of a holistic age assessment of accompanied refugee children with age uncertainty by exploring cultural narratives of age.

METHODS

Seven small group, semi-structured interviews with 24 humanitarian entrants (10 male, 14 female) recruited from Afghan, Bhutanese and Burundian communities in Adelaide, Australia were conducted. Interviews were performed with interpreters present, audio-recorded, transcribed verbatim and thematically analysed.

RESULTS

Four themes emerged: the significance of age; ways of remembering age; the refugee experience and its effect on age recall; and the reliability and permissibility of documentation. Age was significant, but understood and remembered differently with knowledge of an exact date of birth not required for functioning in participants' home societies. Information regarding age was embedded in narrative accounts, related to events and other people. Birth was not always registered, with birth and age-containing documentation obtained later in life. These documents often reflected cultural ideas regarding age, rather than recording true chronological age. The refugee experience profoundly affected the ability of people to remember their age by disrupting methods used to recall specific events, including birth.

CONCLUSION

Narrative history provides valuable information regarding age in accompanied refugee children with age uncertainty, and allows for age to be located within a range that approximates true chronological age when age documentation is absent or clearly erroneous. The Age Assessment Tool questionnaire provides health professionals with a framework for conducting age assessment interviews.

Dental age assessment on panoramic radiographs in a Swiss population: a validation study of two prediction models

OBJECTIVES

Dental age assessment methods are widely used for age estimation. This study aimed to analyse the accuracy of a meta-analysis method to estimate dental age in Swiss individuals and to detect potential limitations of the method. Precision of repeated tooth staging using Demirjian's classification on maxillary and mandibular teeth was also assessed.

METHODS

Panoramic radiographs of 50 Swiss white healthy children were analysed. Developing teeth on the left maxilla and mandible and all third permanent molars were staged following Demirjian's classification. Dental age was calculated for each subject, using a random effects model and a fixed effect model, and compared with chronological age.

RESULTS

The mean error of the dental age ranged between -3 and +1 months for both the calculation models. Dental age calculated with the fixed effect model overestimated the age of the subjects (average + 0.10 y, ranging from -1.95 y to +2.16 y) compared with their chronological age, whereas the random effects model underestimated the age (average -0.32 y, ranging from -2.24 y to +1.61 y).

CONCLUSIONS

Demirjian's method allowed a precise repeated staging of maxillary and mandibular developing teeth. For both calculation models, dental age correlated well, on average, with chronological age of Swiss subjects younger than 12 years. The random effects model showed a better accuracy for these subjects than the fixed effect model. However, both models underestimated the chronological age in subjects older than 12 years.