Quantification of secondary dentine formation from orthopantomograms--a contribution to forensic age estimation methods in adults

Age estimation using the ratio of dental pulp to tooth volume by CT scan in dogs

IMPORTANCE

Accurate age estimations in dogs are essential for various veterinary and clinical applications. Traditional methods based on dental appearance are error-prone because of external influences, necessitating the development of more precise methodologies.

OBJECTIVE

This study examined the association between chronological age and pulp to tooth (P/T) volume ratio in dogs using computed tomography (CT) of the right maxillary canine and right maxillary fourth premolar (PM4) teeth.

METHODS

Ninety-five canine skulls, aged five to 216 months, were examined using a two-slice CT scan machine. Volumetric analyses of the right maxillary canine and PM4 were performed. Statistical analysis, including Spearman's correlation and regression analysis, was conducted to assess the relationship between age and the P/T volume ratio.

RESULTS

This study included 60 male and 35 female dogs, with no significant age difference between genders (p = 0.655). A strong negative correlation was observed between age and the P/T volume ratio for the right maxillary canine (r = 0.88, p < 0.001) and PM4 (r = 0.77, p < 0.001) teeth. Logarithmic regression models provided a better fit for age prediction (R² = 0.78 for the right maxillary canine, R² = 0.67 for PM4) compared to linear models.

CONCLUSIONS AND RELEVANCE

CT-based volumetric analysis of the P/T ratio in the right maxillary canine and PM4 teeth offers a precise, non-invasive method for estimating the age of dogs. This technique can improve the accuracy of age estimations, particularly in forensic and clinical settings, providing valuable insights for veterinarians and researchers.

Dentin thickness model: A novel method for dental age estimation using panoramic radiography

The study aims to evaluate the reliability of the novel dentin thickness model based on root parameters when applied to panoramic radiography images of mandibular first molar in the southern Turkish subpopulation. A total of 946 panoramic images were analyzed for the study. The samples were allocated into four age groups: Group 1(between 10 and 18), Group 2(between 19 and 30), Group 3(between 31 and 50), Group 4(between 51 and 78). The dentin thickness model measurements consisted of root dentin thickness of the mesial aspect of the distal root and distal canal width. Regression, intraclass correlation coefficient, and Durbin-Watson analyses were used for statistics. A medium correlation was detected in the dentin thickness model (R = 0.398). Root dentin thickness and canal width had a significant effect (p < 0.05), but gender did not (p > 0.05). Group 3 showed the highest accuracy (p < 0.001). Group 4 presented the lowest correlation with chronological age compared to other age groups (p < 0.001). The dentin thickness model showed a promising result for the dental age estimation with a medium correlation. The dentin thickness model included root measurements of the mesial aspect of the mandibular first molar without any crown parameters in the southern Turkish subpopulation. Gender did not affect the dentin thickness model.

Reliability of a forensic odontology method for age-at-death estimation in adults: A Mexican case study

This study aimed to evaluate the reliability of an age estimation method based on the pulp⁄tooth area ratio by assessing intra- and inter-examiner agreement across five observers at different intervals. Using the same X-ray device and technical parameters, 96 digital periapical X-ray images of upper and lower canines were obtained from 28 deceased people in Central America, whose age at death ranged from 19 to 49 years. Excellent and good agreement of results were achieved, and there were no statistically significant differences. The R2 value for upper teeth (54.0%) was higher than the R2 value for lower teeth (45.7%). The highest intraclass correlation coefficient value was 0.995 (0.993-0.997) and the lowest 0.798 (0.545-0.895). Inter-examiner agreement was high with values of 0.975 (0.965-0.983) and 0.927 (0.879-0.955). This method is adequate for assessing age in missing and unidentified people, including victims of mass disasters.

Comparative evaluation of two different dental age estimation methods using tooth pulp: A CBCT study

AIM

To estimate the age of an individual based on 3D radiographic evaluation of pulp width of maxillary central incisor.

MATERIALS AND METHODS

This study included 185 CBCT images of individuals within age range of 14-64 years. Images were evaluated for maxillary central incisors and pulp width measurements were taken from cementoenamel junction and middle third of root. Obtained data was subjected to correlation and regression analysis from which the age of an individual was predicted. Results of the present study were compared with another study by the same authors.

RESULTS

A negative linear relationship was obtained between age and pulp width. The standard error of estimate (SEE) in sagittal section was 11.36 years and that in coronal section was 11.23 years. The coefficient of determination for sagittal section was 0.107 and for coronal section was 0.127. An obtained regression formula was highly significant. Division of samples into various age groups reduced SEE drastically.

CONCLUSION

It can be concluded that pulp width of maxillary central incisor is a reliable indicator of age estimation.

Evaluation of radiographic visibility of root pulp in mandibular second molars using cone beam computed tomography images for age estimation

The purpose of this study is to estimate chronological age and determine whether individuals were aged under or over 18 years using root pulp visibility (RPV) in cone-beam computed tomography (CBCT) images. The study included CBCT images of 699 individuals aged between 15 and 75 years. One thousand twenty-three mandibular second molar (2M) teeth were evaluated using Olze's RPV method in four stages. Descriptive statistics of the stages and the relationship between the stages and the chronological age were assessed. The distribution of the stages was analyzed according to the 18-year age threshold. There was a positive correlation between RPV stages and chronological ages in both sexes. For females and males, the mean ages of stage 0, stage 1, and stage 2, for females and males, were found as 27.21, 28.93, and 33.68 years, and 37.69, 40.9, and 44.88 years, respectively. Stage 0 and stage 1 were found both in individuals aged under and over 18 years, and stage 2 and stage 3 were not observed in individuals aged under 18 years. The presence of stage 2 and stage 3 may be an indication that an individual is aged over 18 years according to Olze's RPV age estimation method. For more reliable results, 2M teeth should be examined bilaterally in forensic science.

Dental age estimation using the Kvaal method-an evaluation of length and width ratios: a systematic review

This study aimed to systematically review the correlational accuracy between width ratios and length ratios based on the Kvaal methodology with chronological age. This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The search strategy included ProQuest, PubMed, Science Direct, and Taylor and Francis and Willey online without time or language restriction using Kvaal method of age estimation as key words for the search up to December 2021. A team of two researchers independently selected the studies and extracted the data. The Covidence platform was used to systematically organize all titles. The full texts of eligible studies were analyzed. Risk of bias (RoB) was assessed using a modified (to the specific characteristics of this systematic review) checklist based on Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement checklist for observational studies. A total of 658 articles were initially reviewed, but 22 were selected for inclusion. The risk of bias was estimated to be unclear to low overall. Among the length ratios, ratio R showed a strong association with chronological age, followed by ratio P. For the width ratios, ratio B demonstrated a close association with chronological age, followed by ratio C. The results suggest that width ratios correlate better with chronological age than length ratios. This systematic review suggests the width ratios are more strongly associated with chronological age than the length ratios. Using a width ratio could serve as a convenient and rapid way to estimate dental age. Our results apply equally to all types of ethnic groups.

From Deutsche Zeitschrift to International journal of legal medicine-100 years of legal medicine through the lens of journal articles, Part 4: International journal of legal medicine from 1990 to 2022

This is the fourth and final paper in a series related to the analysis of articles published in this journal during its first 100 years of activity. This article covers the time span from 1990 to 2022. It is important to note that, given the period covered by this analysis, it does not aim to provide a historical overview but rather an examination of the most recent trends in our discipline compared to the past. Between 1990 (Volume 104) and 2022 (Volume 136), 4004 articles were published in the International Journal of Legal Medicine (IJLM) across 33 volumes. This corresponds to 53% of all the articles published since the launch of the journal. When compared to the period from 1970 to 1990, some categories no longer appear to be as relevant (e.g., sexual medicine, 1 article; social medicine, 0 articles; biography, 3 articles; history, 4 articles). Conversely, the most recent period has shown an increasing importance in forensic genetics (1388 articles) and the emergence of new significant topics that merit their own classification, such as age estimation (286 articles), forensic anthropology (189 articles), forensic imaging (150 articles), and forensic entomology (90 articles).

Combining the third molar mineralization to further improve the accuracy of the Kvaal's method in dental age estimation of subadults in northern China

The morphological changes based on deposition of secondary dentin and mineralization of the third molar have been proven to be related to chronological age. However, Kvaal's method on the theory of deposition of secondary dentin was controversial with respect to dental age estimation in the recent research. The aim of this study was to combine the parameters of Kvaal's method with relatively high correlation coefficients and mineralization stages of the third molar to improve the accuracy of predicting the dental age of subadults in northern China. A total of 340 digital orthopantomograms of subadults aged from 15 to 21 years were analysed. A training group was used to test the accuracy of the original Kvaal's method and to establish novel methods for subadults in northern China. A testing group was used to compare the accuracy of the newly established methods with the Kvaal's original method and with published method specifically used in northern China. To increase the feasibility of our estimation model, we combined the mineralization of the third molar to build a combined specific formula. The results showed that the combined specific model increased the coefficient of determination to 0.513, and the standard error of the estimate was reduced to 1.482 years. We concluded that the combined specific model based on the deposition of secondary dentin and mineralization of the third molar could improve the accuracy of dental age assessment of subadults in northern China.

KEY POINTS

The decrease in the dental pulp cavity based on deposition of secondary dentin is a useful variable for assessing age.A total of 340 orthopantomographs were used in this research, including 278 in training groups and 62 in testing groups.Original Kvaal's method underestimated the dental age for subadults in northern China.The equation of combined specific method constructed in our study was proved more suitable to calculate dental age for subadults in northern China.

Age Estimation Using Maxillary Central Incisor Analysis on Cone Beam Computed Tomography Human Images

Forensic dentistry plays an important role in human identification, and dental age estimation is an important part of the process. Secondary dentin deposition throughout an individual's lifetime and consequent modification in teeth anatomy is an important parameter for age estimation procedures. The aim of the present study was to develop regression equations to determine age in adults by means of linear measurements and ratios on sagittal, coronal and axial slices of maxillary central incisors using cone bean computed tomography (CBCT). Multiplanar measurements of upper central incisors were taken for a sample of 373 CBCTs. Subsequently, one-way analysis of variance (ANOVA) and multivariate linear regressions were performed for age estimation. The equations obtained from axial linear measurements and ratios presented a standard error of the estimate (SEE) of ±10.9 years (R² = 0.49), and a SEE of ±10.8 years (R² = 0.50), respectively. The equation obtained for multiplanar linear measurements presented a SEE of ±10.9 years (R² = 0.52), while the equation for multiplanar ratios presented a SEE of ±10.7 years (R² = 0.51). Thus, CBCT measurements on upper central incisors were found to be an acceptable method for age estimation. Horizontal measurements, especially pulp measurements, improve the accuracy of age estimate equations.

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.

Age Estimation by Kvaal's Method Using Digital Panoramic Radiographs in the Saudi Population

Introduction

In forensic literature, estimating an individual's age has garnered a lot of attention. With increasing age, the size of the dental pulp cavity shrinks as a result of secondary dentin deposits. This could be used as a measure of age. Aside from morphological approaches, radiological approaches might be used to analyze this regression shift. Kvaal's method calculates the chronological age of individuals based on the age-pulp size relationship on periapical dental radiographs.

Purpose

This study aims to use Kvaal's method to estimate the chronological age of patients using digital panoramic radiographs and verify the validity of regression equations proposed by Kvaal et al. in the Saudi population.

Material and methods

A total of 74 digital orthopantomograms were randomly selected from Qassim University Dental Clinic in Saudi Arabia, ranging in age from 18 to 64 years (mean age 32 years). The radiographs were taken between 2018 and 2021 according to inclusion and exclusion criteria.

Results

When the Kvaal technique was applied to Saudi members, there was no statistically significant discrepancy between the estimated and chronological ages. The coefficient of determination R2 was highest when three mandibular teeth were evaluated together (0.752).

Conclusion

The most accurate indicator for age assessment was "M" (mean worth, all things considered) and "W L" (contrast among "Width" and "Length").

A retrospective institutional study of human age determination by evaluating the pulp length and width ratio of the maxillary lateral incisor on panoramic radiographs in Indonesian subjects

Purpose

The pulp length to width (PL/W) ratio of the maxillary lateral incisor can be used as an age determination method. This study aimed to investigate the correlation between the PL/W ratio of the maxillary lateral incisor on panoramic radiographs and human chronological age in Indonesian subjects.

Materials and Methods

This study analyzed with 134 maxillary lateral incisors on 113 panoramic radiographs from patients who visited the Oral and Maxillofacial Radiology Unit of Dental Hospital Universitas Padjadjaran, Bandung, Jawa Barat, Indonesia, from 2013 to 2018 (age range: between 11 to 60 years). The pulp length was measured from the pulp chamber roof to the apical foramen, and the pulp width was measured on the cervical area of the cementoenamel junction in millimeters using Fiji ImageJ open-source software. Simple linear regression (in SPSS) was used to analyze the results. The reliability of the observers was evaluated.

Results

The PL/W ratio of the maxillary lateral incisor was significantly correlated with chronological age (P<0.01). No statistically significant difference was found in the PL/W ratio between the left and right maxillary lateral incisors (P=0.333). There was a very strong correlation (r=0.939) between the PL/W ratio of the maxillary lateral incisor and human chronological age, with the following formula: age= -3.057+1.875×PL/W ratio (R²=0.882, standard error of estimate: 4.659).

Conclusion

The PL/W ratio of the maxillary lateral incisor on panoramic radiograph can be used for age determination in Indonesian subjects.

Dental age estimation of Tibetan children and adolescents: Comparison of Demirjian, Willems methods and a newly modified Demirjian method

Tibetan ethnic group is one of the oldest ethnic groups in China and South Asia. This study set out to analyze the dental development and validate Demirjian method and Willems method in estimating dental age of Tibetan children and adolescents, and to modify Demirjian method based on Tibetan population to provide ethnic-specific reference data and a more reliable method for forensic age assessment in Tibetan ethnic group. In this study, 1951 samples aged between 4 and 15 years were retrospectively collected and analyzed. Multiple linear regression was used to establish relationship between chronological age (CA) and developmental stages of left mandibular permanent teeth. The accuracy of the modified method was tested and compared with that of Demirjian and Willems method. Results showed that dental maturity score (DMS) was significantly greater in girls than in boys in all age groups except for the 4-year age group (p < 0.05). Mean absolute error (MAE) was 0.96 years for both boys and girls by Demirjian method, and 1.06 and 1.16 years for boys and girls respectively by Willems method. Adjusted scores table was established and tested. The age of boys was overestimated by 0.13 years and the age of girls was underestimated by 0.06 years by the adjusted scores table. MAE was lower than that of the other two methods. In conclusion, Demirjian method and Willems method was not sufficiently accurate in estimating dental age of Tibetan population. The modified method was more suitable for dental age estimation of Tibetan population than Demirjian and Willems method.

The impact of age mimicry bias on the accuracy of methods for age estimation based on Kvaal's pulp/tooth ratios: a bootstrap study

INTRODUCTION

Methods based on pulp/tooth ratios proposed by Kvaal et al. (1995) have been widely used for age estimation in adults. The tendency of age estimates to mimic the age structure of the reference population, i.e. age mimicry bias, is a possible source of controversy in the results of studies. The primary objective of the present study was to evaluate the effect of age mimicry bias on the accuracy of the original Kvaal's method and its recent modification proposed by Roh et al. (2018).

METHOD AND MATERIAL

The study sample comprised 240 cone-beam computed tomography scans of an Iranian population. The bootstrap procedure was used to study the impact of age mimicry bias on age estimates by constructing reference populations with different age structures. The accuracy of Kvaal's and Roh's variables for age estimation was assessed using a twofold cross-validation technique and principal component analysis.

RESULTS

The application of original equations resulted in SEE values highly greater than the acceptable threshold for forensic purposes (10 years). The population-specific equations obtained SEE values of 9.18, 11.03, and 9.22 years using Kvaal's variables and 9.19, 11.13, and 9.14 years using Roh's variable for the maxillary, mandibular, and all teeth, respectively. The bootstrap procedure revealed that using uneven reference populations to formulate the equation resulted in significantly greater SEEs (almost all >10 years) that were not acceptable for forensic purposes. Moreover, using an older (a younger) reference population contributed to a sharp rise in the amount of over- (under-) estimation for younger (older) age groups.

CONCLUSION

Age mimicry bias had an undesirable impact on the accuracy of dental age estimation based on Kvaal's and Roh's methods. The accuracy of the original equations was low for age estimation in the Iranian sample. However, the performance of the population-specific equations was reasonably acceptable for the maxillary and all six teeth.

Age-dependent decrease in dental pulp cavity volume as a feature for age assessment: a comparative in vitro study using 9.4-T UTE-MRI and CBCT 3D imaging

Evaluation of secondary dentin formation is generally suitable for age assessment. We investigated the potential of modern magnetic resonance imaging (MRI) technology to visualize the dental pulp in direct comparison with cone beam computed tomography (CBCT). To this end, we examined 32 extracted human teeth (teeth 11–48 [FDI]) using 9.4-T ultrashort echo time (UTE)-MRI and CBCT (methods). 3D reconstruction was performed via both manual and semi-automatic segmentation (settings) for both methods in two runs by one examiner. Nine teeth were also examined by a second examiner. We evaluated the agreement between examiners, scan methods, and settings. CBCT was able to determine the pulp volume for all teeth. This was not possible for two teeth on MRI due to MRI artifacts. The mean pulp volume estimated by CBCT was consistently higher (~ 43%) with greater variability. With lower variability in its measurements, evaluation of pulp volume using the MRI method exhibited greater sensitivity to differences between settings (p = 0.016) and between examiners (p = 0.009). The interactions of single-rooted teeth and multi-rooted teeth and method or setting were not found to be significant. For examiner agreement, the mean pulp volumes were similar with overlapping measurements (ICC > 0.995). Suitable for use in age assessment is 9.4-T UTE-MRI with good reliability and lower variation than CBCT. For MRI, manual segmentation is necessary due to a more detailed representation of the interior of the pulp cavity. Since determination of pulp volume is expected to be systematically larger using CBCT, method-specific reference values are indispensable for practical age assessment procedures. The results should be verified under in vivo conditions in the future.

Age estimation in the living: A scoping review of population data for skeletal and dental methods

Age estimation of living individuals has become a crucial part of the forensic practice, especially due to the global increase in cross-border migration. The low rate of birth registration in many countries, hence of identification documents of migrants, especially in Africa and Asia, highlights the importance of reliable methods for age estimation of living individuals. Despite the fact that a number of skeletal and dental methods for age estimation have been developed, their main limitation is that they are based on specific reference samples and there is still no consensus among researchers on whether these methods can be applied to all populations. Though this issue remains still unsolved, population information at a glance could be useful for forensic practitioners dealing with such issues. This study aims at presenting a scoping review and mapping of the current situation concerning population data for skeletal (hand-wrist and clavicle) and dental methods (teeth eruption and third molar formation) for age estimation in the living. Two hundred studies on the rate of skeletal maturation and four hundred thirty-nine on the rate of dental maturation were found, covering the period from 1952 and 2020 for a total of ninety-eight countries. For most of the western and central African countries there are currently no data on the rate of skeletal and dental maturation. The same applies to the countries of the Middle East, as well as the eastern European countries, especially as regard the skeletal development.

Age estimation in Brazilian adults by Kvaal's and Cameriere's methods

The aim of this study was to verify the precision and applicability of two methods of age estimation, Kvaal's and Cameriere's methods, among Brazilian adults. A sample composed of periapical radiographs of canine teeth belonging to 320 Brazilian adults was analyzed, divided into groups according to sex (male and female) and age group (20-29 years, 30-39 years, 40-49 years and 50-59 years). Kvaal's method presented better results when compared to the results of Cameriere's method in the general evaluation of each canine tooth, except for the upper left canine (tooth 23), which presented a mean error (ME) with no statistically significant difference between the methods (Kvaal: ME = 7.43, p = 0.4991, Cameriere: ME = 7.55, p = 0.6982). In the evaluation by age groups, Kvaal's method presented a lower variation between the real age and estimated age when applied to the age groups of 20-29 years and 30-39 years compared to the results provided by Cameriere's method. With respect to the groups aged 40 to 49 years and 50 to 59 years, Cameriere's method presented better performance than the results provided by Kvaal's method. The methods of estimating age proposed by Kvaal and Cameriere are simple and nondestructive and have demonstrated reproducibility and reliability. The Kvaal method was more accurate for the age groups of 20-29 and 30-39 years, and for those over 40 years, the Cameriere method was the most accurate.

Applicability of pulp/tooth ratio method for age estimation

The purpose of this study was to evaluate the reliability of the tooth/pulp ratio method in the process of age estimation at the moment of death in a forensic context and compare it with standard anthropological methods. After the exhumation of mass graves located in sites in Batajnica, Serbia, in 2002 and 2003, skeletal material was thoroughly analyzed by a group of anthropologists and pathologists. As a part of the investigation, orthopantomography (OPG) was performed for each individual. During 2018 these OPGs were reexamined for scientific purposes. Age-at-death was assessed by means of the pulp/tooth ratio method applied to all available lower premolars. Estimated age following standard anthropological methods and chronological age (obtained after DNA identification of victims) was taken from the records. Age estimation using the pulp/tooth ratio and standard methods was compared with chronological age. The pulp/tooth ratio method was accurate in 81.25% of all cases and the standard method was accurate in 56.25% of all cases. The pulp/tooth ratio method of age estimation was found to be applicable and accurate. However, age estimation should be based on all available methods.

Age estimation by pulp to tooth area ratio in canine teeth using cone-beam computed tomography

Background

This study aimed to estimate the chronological age of individuals according to the correlation of age with morphological variables of the maxillary canine teeth using cone-beam computed tomography (CBCT) based on Kvaal’s method.

Method

This study was conducted on CBCT scans of 300 patients in Hamadan city, including 142 females and 158 males between 14 and 60 years of age. To measure the morphological variables, cross-sectional views of the maxillary right canine tooth were studied. The pulp to tooth area ratio (AR), the pulp to tooth length ratio (P), the mesiodistal and the buccolingual pulp to tooth width ratio at the cementoenamel junction (CEJ) (A1, A2), the mesiodistal and buccolingual pulp to tooth width ratio at the mid-root (C1, C2), and the mesiodistal and buccolingual pulp to tooth width ratio at the midpoint between the CEJ and the mid-root (B1, B2) were measured on CBCT scans.

Results

A significant inverse correlation was noted between age and all measured variables. No significant difference was found in the mean variables between males and females. The correlation between the actual age and estimated age in the regression model was 0.88. The mean square error (MSE) of prediction was 5.89 years; also, the mean absolute error (MAE) was 4.46 years.

Conclusion

The fitted regression model suggested in this study can estimate the age of individuals with acceptable accuracy and mean absolute error of lower than 5 years.

Age estimation using canine pulp volumes in adults: a CBCT image analysis

Secondary dentine deposition is responsible for the decrease in the volume of the pulp cavity with age. Therefore, the volume of the pulp cavity can be considered as a predictor for estimating age. The aims of this study were to investigate the relationship strength between canine pulp volumes and chronological age from homogenous (approximately equal numbers of individuals in each age range) age distribution and to assess the effect of sex as predictor in age estimation. This study was performed on 719 subjects of Pakistani origin. Cone beam computed tomography images of 521 left maxillary and 681 left mandibular canines were collected from 368 females and 349 males aged from 15 to 65 years. Planmeca Romexis® software was used to trace the outline of the pulp cavity and to calculate pulp volumes. Regression analysis was performed to assess the correlation between pulp volumes considering with and without sex as a predictor with chronological age. The obtained results showed that mandibular canine pulp volume and sex have the highest predictive power (R² = 0.33). The relationship between mandibular canine pulp volume and sex with chronological age demonstrates an odd S-shaped non-linear relationship. A statistically significant difference in volumes of pulp was found (p = 0.000) between males and females. The conclusion was that predictions using the pulp volume of the mandibular canine and sex produced the best estimates of chronological age.

Examination of regressive features of third molars for the purpose of age assessment in the living by means of rescaled regression analyses

The main criterion of dental age assessment in living adolescents and young adults is the evaluation of third molars' mineralization. Concerning forensic age assessment after the completion of third molars' mineralization, apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs for mandibular third molars have already been described as regressive features. The present study examines the combination of both these features for the purpose of age assessment in regression analyses after rescaling the data to make it on the interval scale. To this end, a total of 1245 orthopantomograms was evaluated, taken from 606 females and 639 males in the age group of 15-40 years. The apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs were determined for the lower third molars. The correlation of the features with the chronological age was assessed by means of rescaled regression analyses. Furthermore, regression formulas for age assessment were established. The values of the standard error of estimate ranged between 3.55 and 4.52 years. In general, the rescaled regression of the examined features appears to be suited for forensic age assessment. A limitation of the present study is the comparatively low number of evaluable teeth in the examined age group. Due to an incomplete development or a lack of the mandibular third molars, only a mere half of the respective teeth could be included in the statistical analysis.

Age estimation using pulp/enamel volume ratio of impacted mandibular third molars measured on CBCT images in a northern Chinese population

The present study aims to evaluate the relation between chronological age and the ratio of pulp volume (PV) to enamel volume (EV) of impacted mandibular third molars (IMTMs) by using cone-beam computed tomography (CBCT) images and an improved 3D image segmentation technique. A sample of CBCT images of IMTM was collected from 414 northern Chinese subjects (214 male and 200 female clinical patients) ranging in age from 20 to 65 years. The GrowCut effect image segmentation (GCEIS) module algorithm was used to calculate the PV and EV from CBCT images. The total sample was divided into a training group and validation group in a ratio of 7 to 3. The PV/EV ratio (PEr) in the training sample was used to develop a mathematical formula for age estimation as follows: age = - 5.817-21.726 × Ln PEr (p < 0.0001) (Ln, natural logarithm). The mean absolute error (MAE) and root mean square error (RMSE) were used to determine the precision and accuracy of the mathematical formula in the validation group and all samples. The MAEs in the male, female, and pooled gender samples were 9.223, 7.722, and 8.41, respectively, and the RMSEs in the male, female, and pooled gender samples were 10.76, 9.58, and 9.986, respectively. The precise and accurate results indicate that the PEr of IMTM in CBCT images is a potential index for dental age estimation and is possible to be used in forensic medicine.

Relationship Between Pulp Tooth Area Ratio and Chronological Age Using Cone-beam Computed Tomography Images

This study investigated the relationship between chronological age and pulp tooth area ratio (PTR) in maxillary central teeth using cone-beam computed tomography (CBCT) images in the Turkish population. The sample consisted of CBCT images of 120 male and female subjects between 14 and 75 years old. The PTR of the maxillary central teeth was calculated using inVivo 5 software (Anatomage, San Jose, CA). Data were analyzed with independent t-test and Pearson's rank correlation test. There was a significant negative correlation between chronological age and PTR (r = -0.615). The results showed that the PTR of maxillary central teeth is a reliable method for age estimation in the Turkish population.

Dental age estimation in Malaysian adults based on volumetric analysis of pulp/tooth ratio using CBCT data

Forensic odontology plays an important role in human identification and dental age estimation is an integral part of this process. The aim of the study was to investigate the association between chronological age and pulp/tooth volume ratio in a Malaysian population (Malays and Chinese) from cone-beam computed tomography (CBCT) scans, enhanced with Mimics software. Three hundred CBCT scans of 153 males and 147 females, aged between 16 and 65 years were divided into 5 age groups. Volumetric analysis of the pulp/tooth ratio was performed in maxillary left canines, maxillary right canines and maxillary right central incisors. Simple linear regression and Pearson correlation analysis indicated the strongest coefficient of correlation (R) values for maxillary right central incisors (0.83) followed by maxillary right canines (0.74) and maxillary left canines (0.73). Fisher's Z test indicated that dental age estimation is gender independent. The derived regression equations were further validated on an independent group of 126 teeth. The results indicated mean absolute error (MAE) values of 6.48 and 8.58 years for maxillary right central incisors and maxillary canines respectively. It was also noticed that MAE values were higher among the age groups ranging from 46 to 65 years. This study showed that a volumetric change in the pulp cavity with age is a valuable assessment method for dental age estimation among Malaysian population.

Digitized Morphometric Analysis using Maxillary Canine and Mandibular First Molar for Age Estimation in South Indian Population

Background:

In recent years, the estimation of age in living individuals have become important to solve judicial or civil problems. Secondary dentin deposition occurs as the age advances and can be measured by calculating the reduction in pulp chamber through Noninvasive radiograph techniques.

Aim:

The aim is to derive precise population specific formulae for age estimation.

Materials and Methods:

Digitalized Orthopantomography of 150 subjects, was retrieved. The subjects were divided into study and test group. Pulp tooth area ratio was recorded from the maxillary canine and pulp chamber crown root trunk height ratio was recorded from a mandibular first molar.

Statistical Analysis:

Regression equation was derived from study group subjects and this equation was used to estimate the age of subjects in the test group.

Results:

No significant differences were seen between mean chronological age and mean estimated age (p-value- 0.157). Mean Absolute Error (MAE) was estimated to be 2.76 years. The percentage of estimated ages in test sample < ± MAE was 72%. The difference was higher in the group I and II (p-value- 0.001 and 0.002)

Conclusion:

The equation derived from the anterior and posterior teeth together gave more accurate results in the present study. The prediction accuracy can further be enhanced by using multiple teeth or by utilizing other linear measurements in the same teeth.

Erosive and Mechanical Tooth Wear in Viking Age Icelanders

(1) Background: The importance of the Icelandic Sagas as a source of information about diet habits in medieval Iceland, and possibly other Nordic countries, is obvious. Extensive tooth wear in archaeological material worldwide has revealed that the main cause of this wear is believed to have been a coarse diet. Near the volcano Hekla, 66 skeletons dated from before 1104 were excavated, and 49 skulls could be evaluated for tooth wear. The purpose of this study was to determine the main causes of tooth wear in light of diet and beverage consumption described in the Sagas; (2) Materials and methods: Two methods were used to evaluate tooth wear and seven for age estimation; (3) Results: Extensive tooth wear was seen in all of the groups, increasing with age. The first molars had the highest score, with no difference between sexes. These had all the similarities seen in wear from a coarse diet, but also presented with characteristics that are seen in erosion in modern Icelanders, through consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and was used for the preservation of food in Iceland, until fairly recently; (4) Conclusions: It is postulated that the consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear seen in ancient Icelanders.

Orthodontic Treatment: Real Risk for Dental Age Estimation in Adults?

Dental age estimation becomes a challenge once the root formation is concluded. In living adults, one dental age indicator is the formation of secondary dentine, also associated with orthodontic treatment as well as root shortening. The aim of this study was to establish whether these secondary effects of orthodontic treatment could generate a statistically significant difference in dental age estimations when using Kvaal's method. The study sample included 34 pairs of pre- and postorthodontic panoramic radiographs, from different individuals with exactly the same age and sex distribution. Females 65%, median age 17.5 years, and males 35%, median age 22.5 years, were included. After data collection, dental age was estimated per tooth using formulae previously published. The risk of obtaining over-estimation of age was calculated. (RR = 1.007). The changes caused by orthodontic treatment do not have any significant effect on age estimation when Kvaal et al.'s method is applied on panoramic radiographs.

Relationship between pulp-tooth volume ratios and chronological age in different anterior teeth on CBCT

Background

The CBCT imaging technique exhibits proper accuracy to determine the internal anatomy of teeth. Therefore, this technique can use to estimate age by measuring the amount of decrease in the volume of the pulpal cavity of teeth. The aim of the present study was to evaluate the correlation between chronological age and pulp-to-tooth volume ratios in anterior teeth with the use of the CBCT technique and to determine a regression model to estimate human age.

Material and Methods

In this present descriptive-analytical study, 122 subjects (46 males and 76 females), with an age range of 13-70 years, were evaluated. The MIMICS software program was used to determine the pulp-to-tooth volume ratios in 732 anterior teeth. Regression analysis was used to assess the correlation between age and pulp to tooth volume ratios.

Results

In all the teeth evaluated, there was an inverse and significant correlation between age and the pulp-to-tooth volume ratios in males and females, with a stronger correlation in males. In addition, such a correlation was stronger in maxillary central incisors and canines. In the model in which the mean of ratios in anterior teeth was used to estimate age the correlation was stronger compared to that in single tooth.

Conclusions

In general, the results of the present study showed that it is advisable to use the mean of all the ratios of anterior teeth in forensics to estimate age.

Key words:Age estimation , cone-beam CT, forensic dentistry, secondary dentin, pulp cavity.

Age estimation in adults by dental imaging assessment systematic review

IMPORTANCE

The need to rely on proper, simple, and accurate methods for age estimation in adults is still a world-wide issue. It has been well documented that teeth are more resistant than bones to the taphonomic processes, and that the use of methods for age estimation based on dental imaging assessment are not only less invasive than those based on osseous analysis, but also have shown similar or superior accuracy in adults.

OBJECTIVES

To summarise the results of some of the recently most recently cited methods for dental age estimation in adults, based on odontometric dental imaging analysis, to establish which is more accurate, accessible, and simple.

EVIDENCE REVIEW

A literature search from several databases was conducted from January 1995 to July 2016 with previously defined inclusion criteria.

CONCLUSION

Based on the findings of this review, it could be possible to suggest pulp/tooth area ratio calculation from first, upper canines and other single rooted teeth (lower premolars, upper central incisors), and a specific statistical analysis that considers the non-linear production of secondary dentine with age, as a reliable, easy, faster, and predictable method for dental age estimation in adults. The second recommended method is the pulp/tooth width-length ratio calculation. The use of specific population formulae is recommended, but to include data of individuals from different groups of population in the same analysis is not discouraged. A minimum sample size of at least 120 participants is recommended to obtain more reliable results. Methods based on volume calculation are time consuming and still need improvement.

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.