Third molar development in a London population of White British and Black British or other Black ethnicity

Population differences in dental development between Black and White ethnic groups have been debated but not previously studied in the UK. Using inappropriate data for dental age estimation (DAE) could lead to erroneous results and injustice. Data were collected from dental panoramic radiographs of 5590 subjects aged 6–24 years in a teaching hospital archive. Demirjian stages were determined for left-sided teeth and third molars and data collected regarding hypodontia and third molar agenesis. Third molar development in self-assigned Black British, including other self-assigned Black ethnicity, was compared with that of self-assigned White British subjects. Data were compared for males and females in the two ethnic groups using T-tests for Demirjian Stages A–G of third molar development and Mann-Whitney tests for Stage H once a cut-off age at the maximum age for Stage G had been imposed. Third molar development occurred earlier in subjects of Black ancestry compared to those of White ancestry. While both ethnic groups showed large age ranges for every third molar stage, in female subjects these generally occurred at least 1.5 years earlier, and in males at least one year earlier. Hypodontia and third molar agenesis were more prevalent in White British, but the ethnic difference in third molar development persisted in subjects with complete dentitions. This is a large study that confirms ethnic differences in a London population, emphasises the difficulties of establishing the 18-year-old threshold using DAE, and confirms the risk of overestimating the age of individuals of Black ethnicity using White ethnic reference data.     

Accuracy of Identifying Juvenile/Adult Status from Third Molar Development using Prediction Probabilities Derived from Logistic Regression Analysis

The use of third molars in predicting juvenile/adult status (</≥ 18 years) has important legal ramifications. Third molar development was assessed using Köhler's grading on 268 orthopantomograms of Indian subjects. Logistic regression analysis was applied to determine allocation accuracy of juvenile/adult status and the level of probability that is “reliable” in predicting juvenile/adult status. Allocation accuracies ranged between 75.8% and 78.2% for the sexes combined, with minimal male‐female differences. Adults were categorized more accurately than juveniles, suggesting that Köhler's grading puts Indian juveniles at greater risk of unwarranted punishment. In both sexes, juvenile/adult status was “reliably” predicted when the probability was >80% using individual third molars (excepting the lower right third molar in males); combining upper and lower third molars on the left/right sides, “reliable” predictions were possible when the probability was >80% and >90% for females and males, respectively. Overall, “reliable” juvenile/adult status prediction was achieved in c. 36% of subjects.     

The Reliability of Chronological Age Determination by Means of Mandibular Third Molar Development in Subjects in Croatia*

Abstract: The aim of this study was to determine the development of the mandibular third molar and its relation to chronological age. The evaluated material consisted of 979 orthopantomograms of patients of Croatian Caucasian origin aged between 5.7 and 14.6 years. Third molar developmental stages were evaluated according to the stages proposed by Nolla. The frequencies of different stages of mineralization and the mean value of the mineralization of the mandibular third molars with regard to age, gender, and size of the mandible were determined and the coefficient of correlation determined between the age of the subject and the stage of development of the mandibular molars. Statistically significant correlation was determined between mineralization of the mandibular third molar and chronological age of the subjects (boys, mandibular left third molar r = 0.779, right third molar r = 0.793; girls, mandibular left third molar r = 0.746, right third molar r = 0.725). It can be concluded that the accuracy of age estimation based on Nolla’s method is applicable for Croatian children.     

Status of Mandibular Third Molar Development as Evidence in Legal Age Threshold Cases

The completion of the third molar roots has played an important role in ascertaining whether individuals may be at or over a legal threshold of age, often taken as 18 years. This study demonstrates that root apex completion in the third molar is relatively uninformative regarding the threshold of age 18 years in a sample of 1184 males, where mean age‐of‐attainment of root apex completion for third mandibular molars is about 19.4 years. This paper also considers the legal age threshold problem for cases where the third mandibular molar is not completely formed, and outlines the use of parametric models and Bayes’ factors to evaluate dental evidence in statistically appropriate ways. It attempts to resolve confusion over age‐within‐stage versus age‐of‐attainment, likelihood ratios versus other diagnostic tests, and prior odds for a case versus the prior density for an age distribution.     

Reliability of Third Molar Development for Age Estimation in a Texas Hispanic Population: A Comparison Study*

Abstract: Evaluating third molars from 950 Hispanic individuals aged 12–22 years using Demirjian’s schematic for crown and root formation found that Hispanic third molar development was 8–18 months faster than American Caucasians as reported by Mincer, Harris and Berryman in 1993. This represents a statistically significant increase. Earlier development was more apparent in the later stages F through H. Hispanic males reach developmental stages faster than Hispanic females and maxillary third molars reach developmental stages faster than mandibular third molars in both sexes. The earliest age observed for stages B–H (e.g., Stage H first observed at age 13.92 years in females) and the oldest age observed for Stages B–G were developed to facilitate age prediction of unknown individuals. Prediction tables for minimum and maximum age for an observed stage (e.g., if a female maxillary third molar is stage F it means she is older than 13 years) for each sex‐jaw group were calculated.     

Estimation of legal age using calcification stages of third molars in living individuals

The increased number of adolescents and young adults with unknown or inaccurately given date of birth is a current issue in justice and legal medicine. The objective of this study was to determine the extent to which third molar calcification stages assessed on panoramic X-rays could be useful as additional criteria for forensic age estimation in living individuals, focusing on the legally important ages 17 and 18.In a retrospective multi-center study, the developmental stage of each individual's third molar was analyzed using Demirjian's scale in 2360 cases. Additionally, sex, age and ancestry were assessed.Individuals with the lowest calcification stage of all present molars in stage H were ≥ 18 years with a likelihood of ≥ 99.05% in the female (n = 388), and ≥ 99.24% in the male (n = 482) population.The lowest calcification stage of all present third molars proved to be useful as an additional reliable criterion for the determination of an age ≥ 18 years.     

The Effects of Racemization Rate for Age Estimation of Pink Teeth

Pink teeth is thought to result from the seepage of hemoglobin caused by dental pulp decomposition. We investigated whether racemization can be applied for age estimation in cases of pink teeth where the whole tooth is used. The pink teeth used were three cases and the normal teeth for control were five mandibular canines of known age. Age of the pink teeth was calculated on the basis of regression formula obtained from the five control teeth. Only a slight error was noted between the actual and estimated ages of the pink teeth (R² = 0.980, r = 0.990): Cases 1–3 actually aged 23, 53, and 59 years were estimated to be 26, 52, and 60 years. Based on our results of testing pink teeth of known age, we suggest that racemization techniques allow for the age estimation of pink teeth using the same methods for normally colored teeth.     

Methamphetamine and alcohol detection in vehicle-driver fatalities in South Australia: A 10-year survey (2008–2018)

Motor vehicle driver fatalities (≥18 years) from the files at Forensic Science South Australia were reviewed from January 2008 to December 2018 for cases in which either positive blood sample for methamphetamine (MA) or an illegal blood alcohol concentration (BAC) >0.05g/100 ml were found. Three hundred driver deaths were found with MA detected in 28 cases (age range 21–62 years; ave. 37.8 years; M:F 23:5). Hundred and fifteen cases with a BAC > 0.05 g/100 ml were identified (age range 18–67 years; ave 35.7 years; M:F 95:20). No change was found in numbers of MA cases, although alcohol cases showed a significant decline (p < 0.001). Drunk driving-related fatal crashes tended to occur in the evening (5 p.m. to 11 p.m.), while MA-related fatal crashes had a longer peak extending from late evening until late morning (11 p.m. to 8 a.m.). This study has demonstrated that while roadside breath testing, legislative changes, and increased monitoring have resulted in reduced levels of drunk driving, similar safety countermeasures have had negligible effects on MA use in drivers. Continued monitoring of MA use by drivers will, therefore, be necessary to assess the possible effects, or not, of new countermeasures.     

Putrefaction: An Additional Complicating Factor in the Assessment of Freshwater Drownings in Rivers

Background hypothesis: That bodies immersed in freshwater (rivers) may show greater changes of decomposition than bodies immersed in saltwater (sea). Fifty de‐identified river drownings and 50 sea drownings were randomly selected from autopsy files at Forensic Science SA, Adelaide, Australia and assessed for decomposition. Results: The river cases consisted of 43 males and seven females (M:F 6:1); age range of 2–92 years (mean 46.8 years); decomposition—16/50 (32%); postmortem interval 1–14 days, average 3.8. The sea cases consisted of 36 males and 14 females (M:F 2.6:1); age range of 9–81 years (mean 50.7 years); decomposition—2/50 (4%) (p < 0.001%); postmortem interval 1–6 days, average 2.8. As decomposition reduces information obtained at autopsy, postmortem examination of deaths in rivers may be less informative than deaths that have occurred in the sea. The reasons for less decomposition in the sea include cooler temperatures, exposure to salt and shorter postmortem intervals.     

The Reliability of the Greulich and Pyle Atlas When Applied to a Modern Scottish Population

This study examines the reliability of age estimation utilizing the Greulich and Pyle atlas in relation to a modern Scottish population. A total of 406 left‐hand/wrist radiographs (157 females and 249 males) were age‐assessed using the Greulich and Pyle atlas. Analysis showed that there was a strong correlation between chronological age and estimated age (females R² = 0.939, males R² = 0.940). When age groups were broken down into year cohorts, the atlas over‐aged females from birth until 13 years of age. The pattern for males showed that the atlas under‐estimated age until 13 years of age after which point it consistently over‐aged boys between 13 and 17 years of age. This study showed that the Greulich and Pyle atlas can be applied to a modern population but would recommend that any analysis takes into account the potential for over‐ and under‐aging shown in this study.     

Effect of Lower Third Molar Segmentations on Automated Tooth Development Staging using a Convolutional Neural Network

Staging third molar development is commonly used for age estimation in subadults. Automated developmental stage allocation to the mandibular left third molar in panoramic radiographs has been examined in a pilot study. This method used an AlexNet Deep Convolutional Neural Network (CNN) approach to stage lower left third molars, which had been selected by manually drawn bounding boxes around them. This method (bounding box AlexNet = BA) still contained parts of surrounding structures which may have affected the automated stage allocation performance. We hypothesize that segmenting only the third molar could further improve the automated stage allocation performance. Therefore, the current study aimed to determine and validate the effect of lower third molar segmentations on automated tooth development staging. Retrospectively, 400 panoramic radiographs were collected, processed and segmented in three ways: bounding box (BB), rough (RS), and full (FS) tooth segmentation. A DenseNet201 CNN was used for automated stage allocation. Automated staging results were compared with reference stages – allocated by human observers – overall and per stage. FS rendered the best results with a stage allocation accuracy of 0.61, a mean absolute difference of 0.53 stages and a Cohen's linear κ of 0.84. Misallocated stages were mostly neighboring stages, and DenseNet201 rendered better results than AlexNet by increasing the percentage of correctly allocated stages by 3% (BA compared to BB). FS increased the percentage of correctly allocated stages by 7% compared to BB. In conclusion, full tooth segmentation and a DenseNet CNN optimize automated dental stage allocation for age estimation.     

Development and validation of the Cozart DDS oral fluid collection device

The testing of oral fluid for drugs of abuse has increased significantly over recent years and is now commonplace in drug rehabilitation clinics, the workplace, prisons and custody suites. The global problem of identifying drugged drivers has also led to an increase in oral fluid testing at the roadside. The main requirements for the implementation of roadside drug testing are a rapid sample collection time, collection of a known sample volume and recovery of drugs from the collection device. We report here the development of the Cozart^® DDS oral fluid collector, an oral fluid collector that combines rapid and adequate sample collection with satisfactory drug recovery. Oral fluid was collected from drug users (n = 134) and drug-free individuals (n = 137), using the Cozart^® DDS oral fluid collector. The mean time for the completion of collection (full coloration of the sample presence indicator) was 34 s for drug-free individuals and 44 s for drug users. The average volume collected was 0.34 mL (n = 271). No chemical stimulant (to induce salivation) was used to achieve the collection times observed in either the drug-free or the drug-taking sample populations. Drugs were extracted from the collector using the Cozart^® DDS buffer and drug recovery was determined by Cozart^® enzyme immunoassays. The recovery studies showed that for amphetamine, Δ⁹THC, cocaine, methadone, methamphetamine, morphine and temazepam over 90% of the drug in the sample was eluted from the collector. The Cozart^® DDS oral fluid collector provides a reliable mechanism for the collection of oral fluid at the roadside that achieves the rapid collection times required.     

Estimating Age of Majority on Third Molars Developmental Stages in Young Adults from Thailand Using a Modified Scoring Technique*

Abstract: The aim of this study was to achieve a referral database for dental age estimation of unaccompanied minors of Thai nationality. A total of 1199 orthopantomograms were collected from original Thai women and men equally divided in age categories between 15 and 24 years. On the radiographs, the developmental stage of the third molars was scored applying a modified scoring technique. Inter- and intra-observer reliabilities were tested using kappa statistics. Correlation between the scores of all four wisdom teeth and left–right symmetry were evaluated with Pearson’s correlation coefficient. Student’s t-test on asymmetry was performed and regression formulas were calculated. The present database was the first to assemble third molar developmental scores on radiographs of Thai individuals and provides more appropriate dental age estimation of unaccompanied Thai minors. Future research on similar databases of different nationalities worldwide may expose ethnical influences on dental development.     

Contribution to the Development of Guidelines in the Analysis of Biological Evidence in Sexual Assault Investigations

This investigation intends to study materials and techniques used for biological evidence collection in sexual assault cases and is divided into two stages: in stage one, methods for biological evidence collection (the single swab (including three variants) and the “double swab technique”) were compared; in stage two, swabs’ component material was compared. The sampling was composed of 42 heterosexual couples who provided mock samples. The collection methods in which the whole swab is covered by evidence presented significantly better outcomes (p < 0.001), such as the “double swab technique.” Additionally, nylon swabs proved to present significantly better features regarding the capacity of sample elution, providing significantly higher amounts of DNA (p ≤ 0.034). This study provides guidelines for better collection of biological evidence regarding the collection method using a swab and the proper swab material to utilize.     

The accuracy and precision of third molar development as an indicator of chronological age in Hispanics

The accuracy and precision of chronological age estimation based on the stages of third molar tooth development was studied in a sample of 679 radiographs from individuals of Hispanic origin. The age range was 14.0 to 25.0 years. Eight raters from the University of Texas Health Science Center at Houston Dental Branch evaluated the radiographs according to Demirjian's schematic definitions of crown and root formation. The objective of this study was to evaluate the chronology of third molar development in Hispanics following the protocol of a previous study. Within the Hispanic population, the rate of male third molar development is greater than that of female third molar development for ten stages of crown-root formation. Also within this Hispanic population sample, the rate of maxillary third molar development is ahead of mandibular third molar development. The mean absolute difference between chronological age and estimated age was +/-3.0 years in females and +/- 2.6 years in males.     

Radiographic evaluation of third molar development in relation to chronological age among Turkish children and youth

A sharp increase in forensic age estimation of living persons has been observed in recent years. However, ethnic populations residing in different countries have been insufficiently analyzed. According to 2004 data compiled by the Essen-based Turkey Research Center, there are 3.8 million Turkish people living abroad, and 3.2 million of them reside in European Union countries. Despite the high number of Turks living abroad, little is known about third-molar development for forensic application in this population. Hence, it was considered worthwhile to determine the developmental stages of the third molar in a group of Turkish population, to assess chronological age estimation based on the developmental stages, and to compare third molar development according to sex, age and location. Orthopantomograms of 1134 Turkish patients, ages 4-20 years were examined and third-molar developmental stages were evaluated based on Demirjian's classifications. Orthopantomograms were scored by two different observers, and Wilcoxon matched-pairs signed-ranks test used to test intra- and inter-observer reliability revealed a strong agreement between both intra- and inter-observer measurements. Linear regression analysis was performed to correlate third-molar development and chronological age, and further statistical analysis was performed to determine the relation between sex, age and location. Results showed a strong linear correlation between age and molar development (males: r(2)=0.57; females: r(2)=0.56). Mineralizations of left and right third molars were compared using Wilcoxon tests, and no statistical differences were found. No significant differences were found in third-molar development between males and females. Mandibular third molar crypt formation was observed in 2.4% of patients at age seven and maxillary third molar crypt formation was observed in 1.3% of patients at age seven. A strong correlation was found between third-molar development and chronological age. Among the Turkish population, third molar crypt formation is observable at as early as 7 years in both the mandible and maxilla. Agenesis can be determined conclusively if no radiolucent bud is present by age 14.     

Reproducibility of radiographic stage assessment of third molars

The aim of this study was to determine intra- and inter-observer variability of the developing third molar from panoramic radiographs. Formation of third molars was assessed according to stages described by modified Demirjian et al.'s methods: Moorrees et al. [C.F.A. Moorrees, E.A. Fanning, E.E. Hunt, Age variation of formation stages for ten permanent teeth, J. Dent. Res. 42 (1963) 1490-1502] and Solari and Abramovitch [A.C. Solari, K. Abramovitch, The accuracy and precision of third molar development as an indicator of chronological age in Hispanics, J. Forensic Sci. 47 (2002) 531-535]; in addition, data were also analysed unmodified, i.e. Haavikko [K. Haavikko, The formation and alveolar and clinical eruption of the permanent teeth, an orthopantomograph study, Proc. Finn. Dent. Soc. 66 (1970) 104-170] and Demirjian et al. [A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227]. The sample was a random selection of 73 panoramic radiographs from patients aged 8-24 years. After training, the left maxillary and mandibular third molars were scored on two separate occasions without knowledge of previous scores. Cohen's Kappa and percentage agreement were calculated for each method, for maxillary, for mandibular third molars and combined. Percentage agreement for stages was also calculated. Intra-observer agreement was greater for mandibular third molars compared to maxillary third molars, and better for methods with fewer stages. Kappa values indicated good agreement for most methods; the best was Demirjian et al.'s method for mandibular third molar with very good agreement (K = 0.80) for the first author, good agreement for the second author (K = 0.75) and good agreement between observers (K = 0.75). The stages with best agreement were Demirjian's stage E [A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227] and Moorrees et al.'s stage Cc and R1/4 [C.F.A. Moorrees, E.A. Fanning, E.E. Hunt, Age variation of formation stages for ten permanent teeth, J. Dent. Res. 42 (1963) 1490-1502]. CONCLUSIONS: Having clearly defined stages and fewer stages allowed better reproducibility of third molar formation.     

Sudden Death Due to Hydatid Disease: A Six‐Year Study in the Northern Part of Tunisia

Human ecchinococcosis also known as hydatid disease is a zoonotic infection caused by the tapeworm Ecchinococcus with 2–3 Million cases worldwide. We hereby report a 6 years period study of Sudden death due to hydatidosis aiming to analyze the epidemiological criteria, death circumstances, and autopsy observations attributed to hydatid disease. During the past 6 years, 26 death cases were due to hydatid disease. Our analysis shows that the sex ratio (M/F) was 1.6, the mean age was 31‐year old, and 65% of the subjects lived in rural places. In 17 cases, death occurred in the victim's place, five victims died after a heavy exercise, and in two cases, death occurred immediately after trauma. At autopsy, 91% of the cysts were found in the liver. In three cases, death followed a septic state, and in two cases, it followed an acute respiratory failure. Death was attributed to anaphylaxis in 17 cases.     

Genetic Variants in KCNE1, KCNQ1, and NOS1AP in Sudden Unexplained Death During Daily Activities in Chinese Han Population

Fifty‐six sudden unexplained death (SUD) cases were collected from Chinese Han population, which occurred during daily activities and were autopsy negative in comprehensive postmortem autopsy. The coding exons of potassium channel genes KCNE1, KCNQ1, and nitric oxide synthase gene NOS1AP were sequenced. A synonymous mutation, KCNE1 F54F T>C was identified in 2 SUD cases, which was absent in the control subjects. Neither genotype nor allele frequencies of KCNE1 and KCNQ1 exhibited a significant difference between the SUD and control group. In contrast, the allele frequency (p = 2.7 × 10⁻¹⁰) and genotype frequency (p = 5.9 × 10⁻⁷) of rs3751284, and the genotype frequency (p = 2.9 × 10⁻²) of rs348624 in NOS1AP of SUD were significantly different from that of controls (p < 0.05). Our study suggested that rs3751284 and rs348624 might be susceptibility loci for SUD during daily activities. Larger sample sizes and further molecular studies are needed to confirm or exclude an effect of the NOS1AP SNPs on SUD risk.     

Forensic Dental Age Estimation by Measuring Root Dentin Translucency Area Using a New Digital Technique

Dentin translucency measurement is an easy yet relatively accurate approach to postmortem age estimation. Translucency area represents a two‐dimensional change and may reflect age variations better than length. Manually measuring area is challenging and this paper proposes a new digital method using commercially available computer hardware and software. Area and length were measured on 100 tooth sections (age range, 19–82 years) of 250 μm thickness. Regression analysis revealed lower standard error of estimate and higher correlation with age for length than for area (R = 0.62 vs. 0.60). However, test of regression formulae on a control sample (n = 33, 21–85 years) showed smaller mean absolute difference (8.3 vs. 8.8 years) and greater frequency of smaller errors (73% vs. 67% age estimates ≤ ±10 years) for area than for length. These suggest that digital area measurements of root translucency may be used as an alternative to length in forensic age estimation.