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.     

上、下尖牙髓腔/牙体表面积比值的年龄判定价值研究

目的通过三维重建测量上、下颌尖牙髓腔/牙体表面积比值(Pulp/Tooth area Ratio,PTR)来推断个体年龄,为临床年龄推断的应用提供科学依据。方法收集口腔门诊患者年龄在16~65岁200例锥形束CT(Cone beam computed tomography,CBCT)影像资料,以4个尖牙为测量对象并进行三维重建,测量各尖牙髓腔和牙体表面积,计算PTR值。应用SPSS17.0软件进行统计学分析,推导实际年龄的推断公式。结果Pearson相关分析显示上、下颌尖牙PTR值与实际年龄呈高度负相关(P<0.001,r值为-0.833~-0.891)。4个尖牙间的PTR值无显著差异(P>0.05)。男女性别间尖牙PTR值无显著差异(P>0.05)。尖牙PTR值(x)推断年龄公式为:年龄=84.42-222.22x,R²=0.739。结论检测尖牙的PTR值,可明显提高临床年龄推断的准确性。     

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.     

Dental age assessment: the applicability of Demirjian method in eastern Turkish children

In the literature, little is known about the applicability of this method in Turkish children. The aim of this study was, therefore, to evaluate the reliability of Demirjian method of age estimation when used for eastern Turkish children. A retrospective study was performed on a sample of panoramic radiographs taken from 807 healthy eastern Turkish children. The stages of dental maturity of the mandibular left seven permanent teeth for each subject using the eight radiographic dental maturity stages demonstrated by Demirjian were evaluated. A paired t-test was used for statistical analysis. The mean difference between the chronological and dental ages ranged from 0.2 to 1.9 years in girls and from 0.4 to 1.3 years in boys. The differences between the chronological and dental ages were statistically significant in all age groups. The applicability of Demirjian method is not suitable for eastern Turkish population.     

Age Estimation from Radiographic Images of the Knee

This study examines the reliability of age estimation utilizing the Pyle and Hoerr atlas in relation to a modern Scottish population. The knee radiographs of 442 individuals (168 females, 274 males) were age assessed using the Pyle and Hoerr atlas. Analysis showed that there was a strong correlation between chronological age and estimated age (females R² = 0.968, males R² = 0.952). For females, the atlas method was most accurate between the ages of 9 and 15 years of age with an underage of 2.27 months and an overage of 2.38 months. For males, the atlas consistently overestimated age from the age of 9 years to the age of 16 years from between 0.14 and 8.81 months. The standard deviation for females was 9.86 months and for males was 10.75 months. This study showed that the Pyle and Hoerr atlas can be applied to a modern population with small modifications.     

Validity Comparison of Three Dental Methods for Age Estimation Based on Tooth Root Translucency

Age estimation of nonliving subjects plays a very important role in identifying human remains. When adult remains are in question, this process becomes even more complex. Among the numerous dental methods that exist for adults aging, the evaluation of root translucency is one of the most useful. This study studies the correlation between age and root translucency by investigating monoradicular teeth affected by pathological processes using the equations proposed by Lamendin, Prince & Ubelaker and from Singhal et al. The average age values calculated according to the three methods were compared with the values of known age. Age estimation using the Student's t‐test resulted as more accurate in the methods by Singhal et al. and by Prince & Ubelaker, with respect to that of Lamendin. Age estimation based solely on the percentage of radicular dentinal translucency has been found to be more accurate when diseased teeth are involved.     

Sexual Dimorphism of Maxillary Sinus Dimensions Using Cone‐Beam Computed Tomography

Sex determination of unknown persons plays an important role in forensic medicine. Cone‐beam computed tomography (CBCT) is an excellent imaging modality for accurate measurement of maxillary sinus dimensions. This study aimed to evaluate whether maxillary sinus measurements on CBCT scans can be applied for sex determination. The width, length, and height of maxillary sinuses in CBCT images of 100 patients (50 males and 50 females) were measured. Student's t‐test and discriminant function analysis were used to compare differences in the measured parameters between males and females. The correct predictive accuracy rate of sex determination was 78% in females and 74% in males with overall accuracy of 76%. Based on discriminant analysis, the most pronounced variable in differentiation of sex groups was maxillary sinus height. This study suggests that maxillary sinus measurements can be valuable for sex determination in forensic investigation, especially for cases in which other traditional methods are not applicable.     

Dental Age Estimation: A Test of the Reliability of Correctly Identifying a Subject Over 18 Years of Age Using the Gold Standard of Chronological Age as the Comparator

This study was designed to test the reliability of using the third molars to demarcate between child and adult status. A total of 2000 dental panoramic tomographs were used for assessment of the calculated age using the 8‐stage system of tooth development and applied to all four third molars. The LL8 was also assessed using this 8‐stage system. For each tooth development stage, the Normal distribution and percentile summary data were estimated. The calculated dental age compared with the chronological age was statistically significantly different (p < 0.001) for both females and males giving underestimates of the true age. Comparison of single tooth dental age and chronological age was only slightly different. The most important finding is that the assignment to above or below the 18‐year threshold, in the age range 17 years to 19 years, could be wrong on up to 50% of occasions.     

Age Estimation Based on DNA Methylation Using Blood Samples From Deceased Individuals

Age estimation using DNA methylation levels has been widely investigated in recent years because of its potential application in forensic genetics. The main aim of this study was to develop an age predictor model (APM) for blood samples of deceased individuals based in five age-correlated genes. Fifty-one samples were analyzed through the bisulfite polymerase chain reaction (PCR) sequencing method for DNA methylation evaluation in genes ELOVL2, FHL2, EDARADD, PDE4C, and C1orf132. Linear regression was used to analyze relationships between methylation levels and age. The model using the highest age-correlated CpG from each locus revealed a correlation coefficient of 0.888, explaining 76.3% of age variation, with a mean absolute deviation from the chronological age (MAD) of 6.08 years. The model was validated in an independent test set of 19 samples producing a MAD of 8.84 years. The developed APM seems to be informative and could have potential application in forensic analysis.     

Epiphyseal Union of the Cervical Vertebral Centra: Its Relationship to Skeletal Age and Maturation of Thoracic Vertebral Centra

Epiphyseal union stages for cervical vertebral centra (ring epiphyses) were documented for 55 individuals (females and males, ages 14–27 years) from the Terry Collection, using the Albert and Maples method 1, to examine both its relationship to age at death and to thoracic data collected from the same individuals using the same method. Results showed a moderate correlation between cervical ring union and age (r = 0.63, p = 0.000), and a fairly low correlation between cervical and thoracic ring union (r = 0.41, p = 0.002). Paired samples t‐tests yielded a statistically significant difference between cervical and thoracic union mean values (p = 0.01). Union progressed earlier in cervical vertebrae and in females. Results indicated fairly substantial variation in both sexes. Findings may serve as a basic guideline for estimating a general age range at death for unknown skeletal remains and to corroborate findings from other skeletal age indicators.     

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.     

上颌中切牙牙根直径及根管管径与年龄的关系

目的探讨汉族人上颌中切牙牙根直径及根管管径与年龄的关系。方法 2014年11月~2015年11月间,在一家三甲医院数据库中选择420例汉族人的口腔锥形束CT资料,根据年龄将所有研究对象分为6个组别(8~12岁、13~17岁、18~22岁、23~27岁、28~32岁、33~37岁,每组70例,男女各15例。对所有研究对象上颌中切牙牙根直径及根管管径进行测量,取釉牙骨质界距根尖3/4处,分析上颌中切牙牙根直径及根管管径与年龄的关系,比较男女上颌中切牙牙根直径。结果男性与女性上颌中切牙牙根直径比较具有差异显著性(P0.05);男性与女性上颌中切牙牙根管径比较具有差异显著性(P0.05);男性与女性上颌中切牙牙根直径与牙根管径之比比较具有差异显著性(P0.05);不同性别间上颌中切牙牙根直径与牙根管径之比与年龄具有一定的相关性(R~2=0.623,P0.05)。结论汉族人上颌中切牙牙根直径及根管管径与年龄的变化具有相关性,且男性根管管径减小趋势比女性更高。     

The Use of CT Scans in Estimating Age at Death by Examining the Extent of Ectocranial Suture Closure

We examined the utility of CT scans in the evaluation of degree of ectocranial suture closure. Five cranial points (left and right midcoronal positions, left and right midlambdoidal positions, and the lambda) were evaluated in 231 CT scans using a three‐point scoring system (open, partial closed, and closed). The slice increment and thickness varied between three groups of the scans. The results showed a good correlation between degree of suture closure and increasing age in each group. Young individuals (<40 years) and old individuals (>60 years) could be clearly distinguished from the middle‐aged individuals. ANOVA test revealed no difference between two groups of scans and between left and right sides (p > 0.05). Interobserver agreement was good, especially considering the score by sides. The results of this study create the base for developing a robust and simple method to estimate the age at death using CT scans.     

Application of Kvaal et al.'s age estimation method to panoramic radiographs from Turkish individuals

Age estimation of living adult individuals can be accomplished with limited methods. Radiographic dental methods based on the pulpal narrowing with secondary dentin formation have been presented. In the present study, Kvaal et al.'s method, one of the radiographic dental age estimation methods, was applied to panoramic radiographs from Turkish individuals. The correlation between chronological and estimated ages was examined and the feasibility of length and width measurements of pulp cavity was evaluated for age estimation. The study population consisted of 123 patients with ages ranging from 14 to 57 years. The measurements of the length and width of six types of teeth on digitized panoramic radiographs were performed, and the ratios between tooth and pulp cavity measurements were calculated. Age was estimated using the linear regression models presented by Kvaal et al. and Paewinsky et al. High differences were observed between chronological and estimated ages. Measurement ratios showed no significant or weak correlation with age. The linear regression models were derived using variables that were significantly correlated with age. The determination coefficients of the models varied from 0.035 to 0.345. In conclusion, a difference of more than 12 years in the chronological and estimated ages derived using regression models in literature was found on panoramic radiographs in Turkish individuals. The length and width of the pulp cavity, measured according to the method of Kvaal et al. using panoramic radiographs, were insufficient to precisely estimate the age of Turkish individuals.     

Quantification of Pubic Symphysis Metamorphosis Based on the Analysis of Clinical MDCT Scans in a Contemporary Malaysian Population

Forensic age estimation methods are biased to sex and population; in general, accuracy is reduced when applied to foreign populations. This study assessed the accuracy of the Suchey–Brooks method in contemporary Malaysian individuals and aimed to formulate population‐specific standards. Multi‐detector computed tomography scans of 355 individuals (165 male; 190 female) of 15–83 years of age were reconstructed using 3D‐volumetric rendering in RadiAnt. Pubic symphyseal phase, bias, inaccuracy, and percentage correct age classifications are examined. Transition analysis was used to develop age estimation standards. High observer agreement (κ = 0.763–0.832) and a positive relationship between age and pubic symphyseal phase (r = 0.884–0.90) were demonstrated. Mean inaccuracies were 8.62 and 8.95 years for males and females, respectively; overall correct classification was 97.8%. Transition ages between phases in males were 18.79, 23.29, 28.85, 43.64, and 61.15 years; in females, the corresponding data were 19.77, 22.53, 32.62, 41.85, and 57.39 years.     

A test of the differential accuracy of the maxillary versus the mandibular dentition in age estimations of immature skeletal remains based on developing tooth length

Liversidge and colleagues developed a method for predicting the age of immature skeletal remains based on the length of developing teeth. This quantitative method combines dental data from both jaws, except for the permanent lateral incisor, and because there are reasons to suspect that these two types of data are not identical and should not be combined, it raises concerns regarding the accuracy of the technique when applied differently to each jaw. In this study, the differential accuracy of the method was test when applied to the maxillary and mandibular dentition. The test sample is comprised of 57 Portuguese subadult skeletons of known age at death. Results suggest an overall high consistency between estimates obtained from both jaws, but for the permanent dentition only. In the deciduous dentition the age estimates obtained from the maxillary teeth tend to be greater than the age estimates obtained from the mandibular pair, and the differences are significant for the incisors and canine. Additionally, ages obtained from the maxillary deciduous canine also differ significantly from true chronological age. In the permanent dentition there were no differences between the ages provided by both jaws but both the maxillary and mandibular second molars show a significant tendency to underestimate true chronological age. Although this study cannot validate completely the method presented by Liversidge and colleagues, it does provide an important test to its accuracy and calls for further research into its overall performance, particularly with respect to the results obtained from both jaws.     

Sex Estimation from Human Cranium: Forensic and Anthropological Interest of Maxillary Sinus Volumes

Sex estimation is a key objective of forensic science. We aimed to establish whether maxillary sinus volumes (MSV) could assist in estimating an individual's sex. One hundred and three CT scans were included. MSV were determined using three‐dimensional reconstructions. Two observers performed three‐dimensional MSV reconstructions using the same methods. Intra‐ and interobserver reproducibility were statistically compared using the intraclass correlation coefficient (ICC) (α = 5%). Both intra‐ and interobserver reproducibility were perfect regarding MSV; both ICCs were 100%. There were no significant differences between right and left MSV (p = 0.083). No correlation was found between age and MSV (p > 0.05). We demonstrated the existence of sexual dimorphism in MSV (p < 0.001) and showed that MSV measurements gave a 68% rate of correct allocations to sex group. MSV measurements could be useful to support sex estimation in forensic medicine.     

Bone Mineral Density Adult Age Estimation in Forensic Anthropology: A Test of the DXAGE Application

Estimating age‐at‐death of individuals represented only by skeletonized human remains is a fundamental aspect of forensic anthropological casework. Recently, several researchers have proposed that bone mineral density (BMD) is a useful predictor of age‐at‐death in forensic contexts. Navega et al. (JFS 63(2):497–503) developed an online application called DXAGE for calculating age‐at‐death from BMD parameters. This study tests the utility of DXAGE by utilizing data from the National Health and Nutrition Examination Survey (NHANES). BMD data from a female subsample (n = 470) of the NHANES 2007–2008 dataset were analyzed, and the relationship between predicted age and real age was examined. Inaccuracy was 14.25 years, and bias was ?7.20 years. Results show that there is a weak correlation between predicted and actual age (r = 0.47) using the DXAGE application. While BMD data are potentially useful for predicting age age‐at‐death, the DXAGE application should be used cautiously in forensic anthropological contexts.     

Age Estimation from the Teeth Using a Modified Demirjian System*

Abstract: The estimation of age at time of death is often an important step in the identification of human remains. The purpose of this study was to test the applicability of the Demirjian system on a sample of the Sydney child population and to develop and test age‐prediction models using a large sample of Sydney children (1624 girls, 1637 boys). The use of the Demirjian standards resulted in consistent overestimates of chronological age in children under the age of 14 by as much as a mean of 0.99 years. Of the alternative predictive models derived from the Sydney sample, those that provided the most accurate age estimates are applicable for the age ranges 2–14 years, with R‐square = 0.94 and a 95% confidence interval of ±1.8 years. The Sydney‐based standards provided significantly different and more accurate estimates of age for that sample when compared to the published standards of Demirjian.