Maxillary suture obliteration: a visual method for estimating skeletal age.

The purpose of this study was to develop a method of estimating the age of an individual based on obliteration of the four maxillary (palatal) sutures. A sample of 186 individuals of known age, race, and sex were examined. It was found that males of both races (black and white) exhibit more suture obliteration than females at the same age. During the early adult years, maxillary suture obliteration progresses at nearly the same rate in both sexes; however, the age of old individuals may be greatly overestimated using this method. Although this method cannot be used for exact estimates of individual age, it is valuable in establishing the age range, sorting commingled remains, and estimating skeletal age when only the maxilla is present.     

Maxillary suture obliteration: a test of the Mann method

The degree of obliteration of the maxillary sutures has recently been presented as a useful technique for predicting the age at death of adult skeletal remains. A replicative study of the method on a sample of male skeletons of verified age was undertaken to test its accuracy. Results indicated that the variability in predicted age, as reflected by the total suture score, was too great to recommend use of the method for age determination in individual forensic science cases.     

A Test of Hartnett's Revisions to the Pubic Symphysis and Fourth Rib Methods on a Modern Sample

Estimating age at death is one of the most important aspects of creating a biological profile. Most adult age estimation methods were developed on North American skeletal collections from the early to mid‐20th century, and their applicability to modern populations has been questioned. In 2010, Hartnett used a modern skeletal collection from the Maricopia County Forensic Science Centre to revise the Suchey‐Brooks pubic symphysis method and the ??can et al. fourth rib methods. The current study tests Hartnett's revised methods as well as the original Suchey‐Brooks and ??can et al. methods on a modern sample from the William Bass Skeletal Collection (N = 313, mean age = 58.5, range 19–92). Results show that the Suchey‐Brooks and ??can et al. methods assign individuals to the correct phase 70.8% and 57.5% of the time compared with Hartnett's revised methods at 58.1% and 29.7%, respectively, with correctness scores based on one standard deviation of the mean rather than the entire age range. Accuracy and bias scores are significantly improved for Hartnett's revised pubic symphysis method and marginally better for Hartnett's revised fourth rib method, suggesting that the revised mean ages at death of Hartnett's phases better reflect this modern population. Overall, both Hartnett's revised methods are reliable age estimation methods. For the pubic symphysis, there are significant improvements in accuracy and bias scores, especially for older individuals; however, for the fourth rib, the results are comparable to the original ??can et al. methods, with some improvement for older individuals.     

Age-at-death estimation based on the study of frontosphenoidal sutures

Determination of age at the time of death based on the observation of cranial sutures has led to numerous studies with sometimes contradictory results. The initial hypothesis being that suture closure is part of an age-related physiological process, the conflicting results have been interpreted by various authors as secondary to the choice of sutures, under the co-existing influence of pathological factors or genetic factors, or even independent of age. Despite these differences, macroscopic methods remain much used in anthropology and in forensic medicine. In our work, we evaluated the value of the degree of closure of the frontosphenoidal suture in estimating age at death of mature subjects, with the secondary objective of establishing a linear regression which could be used in routine practice. The study concerned bone specimens from individuals whose age, sex and medical history were known. Macroscopic observation was carried out on the ectocranial and endocranial sides according to four stages of closure previously defined. 290 sutures were taken from a population of whom two-thirds were men. The method can be repeated and reproduced and the regression established shows the confidence range for average error to be +/-1.5 years. While this result is of interest in terms of precision in prediction for a group of people, the prediction range is too great (+/-23 years) to be applicable to a single individual as part of a forensic procedure.     

A Test of the Revised Auricular Surface Aging Method on a Modern European Population

The accurate age estimation of adults is an important step in the construction of the biological profile of skeletonized remains. The auricular surface of the ilium as it was developed in 1985 by Lovejoy et al., is one of the methods employed for age estimation. This study presents the results of a blind test of the revised auricular surface aging method developed by Buckberry and Chamberlain. A sample of 120 individuals from the Athens Collection was used to test this revised aging technique. Almost all features and composite score were positively correlated with known age‐at‐death. The calculation of bias demonstrated no obvious trend for either overestimation or underestimation of age when all individuals were pooled together. Inaccuracy showed that absolute errors of estimated ages against known ages are substantial. The data generated from this study suggest that the revised method can be reliable for age estimation on a modern European population.     

Sex differences and aging of the vertebral column

Morphological changes in the adult human skeleton have been recognized as useful for estimating the age at death. In the vertebral column, the development of osteophytes has been shown to be a general indicator of age, although substantial variation has been documented. The technique used for estimating age from osteophyte development is based exclusively on males and it is unknown whether patterns of osteophyte development are comparable between the sexes. This study examines sex differences in osteophyte development in the thoracic and lumbar regions of 384 individuals from the Terry Collection. Males and females in this sample show remarkably similar patterns of age-related changes in osteophyte development; however, females show greater variability in osteophyte stage for a given age. This was confirmed with age-matching a subsample of 128 individuals. Therefore, slightly larger confidence intervals should be used when assessing age from the vertebral column in females.     

Palatine Sutures as Age Indicator: A Controlled Study in the Elderly

Abstract:  Vault sutures have proven their low reliability for estimating age at death in individual forensic science cases. We broke down the palatine sutures of 134 skulls (with known sex and age at time of death) into 15 subparts and 5 stages of fusion to obtain a mean coefficient of obliteration ( C p) which was then linked to five age classes. We completed this study with multiple regression equations of total palatine suture scores. We compared our results with those obtained using the Mann method on the one hand and classically segmented and scored ectocranial suture age determination methods on the other. Palatine sutures generally do not estimate age at death any better than cranial vault sutures. Despite the partly subjective aspect of suture study, palatine suture observation contributes additional information to age-range estimation, especially in old and very old subjects where other methods lose their effectiveness.     

Auricular surface aging: a blind test of the revised method on historic Italians from Sardinia

Age determination from human skeletal remains is an important biological parameter in both forensic and bioarchaeological contexts. This study presents the results of a blind test of the revised auricular surface age estimation method proposed by Buckberry and Chamberlain (Am. J. Phys. Anthropol. 119 (2002) 321-329) on a large sample (n=404) of known sex and age from the Sassari collection, housed at the Museum of Anthropology, University of Bologna, Italy. Ilia were scored for five features: transverse organization, surface texture, microporosity, macroporosity, and apical changes, which combined for a composite score. The results indicated that all features and the composite score were positively correlated with known age. Composite scores were significantly different between the sexes, suggesting that males and females should be treated separately. Bias and inaccuracy varied across age intervals. Age tended to be overestimated in individuals under age 59 and underestimated for those over age 60 years. However, the revised method showed improvement over the original auricular surface method (Lovejoy et al., Am. J. Phys. Anthropol. 68 (1985) 15-28), especially for aging older individuals. Considerable variation exists in the age ranges derived from composite scores and few significant differences were found between age stages, suggesting that fewer stages with wider age ranges may be necessary. The independent, quantitative scoring of the surface features makes the revised method substantially easier to apply and the method shows significant improvement for aging older individuals.     

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.     

腭缝的年龄变化

作者对231具中国汉族成年男性的干燥颅骨腭缝的年龄变化进行了分析研究。发现腭缝的愈合随着年龄的增加而有规律地增加。并且在45岁以前更加明显。通过对汉族成年男性腭缝愈合与年龄变化关系的研究,从中发现了腭缝愈合年龄变化的初步规律,为骨骼年龄变化的判断提出了一个新的方法。     

Using PMCT of Individuals of Known Age to Test the Suchey–Brooks Method of Aging in Victoria,Australia

The estimation of an individual's age at death plays a critical role in the investigation of unidentified human remains. The Suchey–Brooks method, which involves the analysis of degenerative morphological changes in the pubic symphysis, is currently widely used to estimate age in adults. This study tested the applicability of the Suchey–Brooks method on a contemporary adult Australian (Victorian) subpopulation by observing three‐dimensional volume‐rendered postmortem computed tomographic (PMCT) reconstructions of the pubic symphysis of 204 individuals aged 15–100 years. Results showed the method was reliable for females (85% correct allocations) but not for males (67% correct allocations). It is therefore recommended that extreme caution be used when applying the Suchey–Brooks method for estimating age at death of an individual in this subpopulation from PMCT images. The results suggest further investigation into alternate age estimation methods is required.     

Age estimation using CT imaging of the third molar tooth, the medial clavicular epiphysis, and the spheno-occipital synchondrosis: a multifactorial approach

A multi-factorial method for estimating age was devised based on the development of the 3rd molar tooth, the medial clavicular epiphysis, and the spheno-occipital synchondrosis, using multiple regression as the means to construct age estimation formulae and CT scanning as the imaging modality. The sample consisted of approximately 600 individuals from a contemporary Australian population, between the ages of 15 and 25 years, who were admitted to the Victorian Institute of Forensic Medicine, Melbourne, Australia, for the purposes of medico-legal death investigation. Results show that the spheno-occipital synchondrosis does not contribute to the age estimation model for this age cohort. The regression computation for the 3rd molar tooth and medial clavicle, when combined into a single multiple regression calculation, provides a robust model with tighter age ranges at the 95% confidence interval (CI) than when each age marker is used individually. This research provides a method to estimate age for unknown age Australian individuals in the problematic age group of 15-25 years with greater precision than previously possible.     

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 three dental methods of adult age estimation from intact single rooted teeth to a Peruvian sample

Methods of estimating adult age at death from such dental features as root translucency, root length, and the extent of periodontosis in intact single rooted teeth have proven useful in studies of modern individuals, especially in estimating age in older adults. Questions remain however, concerning the impact of regional and population variation on accuracy. To examine this issue, three approaches to age estimation were applied to a diverse sample of 100 individuals from Peru. Mean errors of estimation for all three approaches were similar to those originally reported, suggesting minimal impact of population variation of the features measured. A new regression equation, specifically for Peruvian samples, is provided.     

Utility of the Frontonasal Suture for Estimating Age at Death in Human Skeletal Remains*

Abstract: This project evaluated the utility of the frontonasal suture for estimating age at death. Utilizing human remains of known age at death with varying degrees of fusion, curated at the American Museum of Natural History in New York City and the Smithsonian Institution’s National Museum of Natural History in Washington, DC, data were collected from the ectocranial surface of 522 crania; 68 of these were sagittally sectioned, allowing collection of internal data and observation of suture closure through the bone. Degree of ectocranial suture closure does not significantly predict age, even when sex and ancestry are accounted for. Suture closure progression data were converted into a Hershkovitz ratio (sum of the measurement of open portion divided by the total suture length), and regression models demonstrate that the effect of age accounts for only 13% of variation in suture closure.     

Age Estimation in Indians Using Demirjian’s 8‐teeth Method

Abstract: Demirjian’s grading of tooth calcification is widely used to assess age of individuals with developing dentitions. However, its application on numerous populations has resulted in wide variations in age estimates and consequent suggestions for the method’s adaptation to the local sample. Conventionally, Demirjian’s method utilized seven mandibular teeth on the left side. A recent modification incorporated the third molar with a view to apply the method on a wider age‐group. Moreover, the revised method developed regression formulas for assessing age. This paper tested the 8‐teeth method using 547 Indians (348 females, 199 males) aged 7–25 years. Demirjian’s formulas resulted in inferior age prediction in Indians (9.2% misclassification at 99% confidence interval vs. 0% misclassification in the original study); therefore, India‐specific regression formulas were developed, which gave better age estimates (mean absolute error, MAE = 0.87 years) than the original formulas (MAE = 1.29 years). This suggests that Demirjian’s 8‐teeth method also needs adaptation prior to use in diverse populations.     

Estimation of age at death by tibial osteon remodeling in an autopsy series

Estimation of age at death by histological methods in tibiae has been found to be inaccurate in individuals less than 55 years of age. This study describes reasons for the inaccurate age estimates and provides a new regression equation for age estimation. Bone cores were removed from tibiae in 53 individuals at autopsy ranging in age from 17 years to 53 years of age; 48 males and 5 females. The sample contained 41 whites and 12 blacks. Variables ascertained from each core were: cortical thickness, cortical bone density, secondary osteon number, area, and perimeter, and Haversian canal area and perimeter. The results showed significant differences in secondary osteon number, area, and perimeter between groups aged less than and greater than 35 years of age. Multiple linear regression analysis indicated osteon number to be the best predictor of age in this sample aged less than 55 years of age. Age at death was accurately estimated for 11 additional forensic cases using osteon number in tibiae. No significant histological differences were observed between males and females and between blacks and caucasians.     

Assessment of age at death by microscopy: unbiased quantification of secondary osteons in femoral cross sections

The microscopic method of age at death determination was introduced by Kerley in 1965 [E.R. Kerley, The microscopic determination of age in human bone, Am. J. Phys. Anthropol, 23 (1965) 149-163.]. However, even though the method has been revised several times, there remain some fundamental issues concerning the reliability of the methods. This is because several basic histological features seen in a cross section of a bone have to be quantified according to the method, but the definition, and hence quantification, of these features leaves room for subjectivity. In a previous study we found that some of these features (osteon fragments and Haversian canals) could not be identified reliably. Only secondary osteons could be identified with a low inter and intra observer error. Furthermore, since the histological features are quantified in only parts of an entire bone cross section, the selection of these parts or areas is a potential source of bias. Finally, unless an unbiased method is used for addressing features on the borders of the selected areas, this will also introduce error. These issues have not been addressed specifically in previous studies. In this study, we used the methods of stereology to choose the regions of interest, as well as for dealing with border phenomena, and we only counted secondary osteons. Our results show a statistically significant increase in the median number of osteons per area unit with increasing age at death. However, this was after exclusion of one outlier. This result is probably due to the limited sample size (N = 24). As such, this study is preliminary, but does warrant applying the described techniques to a larger sample.     

Validity of Demirjian's and modified Demirjian's methods in age estimation for Korean juveniles and adolescents

In estimating age of juveniles and adolescents, the teeth are employed primarily because of its low variability and less affection by endocrine and nutritional status in development. Demirjian established criteria for evaluating maturity of teeth and his method has been used throughout the world. However, several studies showed the inappropriateness of Demirjian's method on populations other than the one it is based on. Consequently some researchers modified Demirjian's method using data of several different populations. Demirjian himself also published a revised method to overcome other shortcomings of his original method. The aim of this study was to test the validity of Demirjian's and the modified methods (Demirjian's revised, Willems', Chaillet's and new Korean methods) for Korean juveniles and adolescents. 1483 digital orthopantomograms which consist of 754 males and 729 females in the age range of 3-16 years were collected. New age estimation method based on Korean population data was calculated. Dental age was estimated according to each method and the validity was evaluated using the differences between chronological and dental age. The inter- and intra-observer reliability was evaluated to be excellent. Statistically significant difference was observed between chronological and dental age in all the methods for both sexes except new Korean method for both sexes and Demirjian's revised method for males. However, when analyzing absolute and squared value of difference, Willems' method was found to be most accurate followed by new Korean method with slight difference for Korean population for both sexes. In conclusion, both Willems' method and new Korean method conducted by present study were proven to be suitable for Korean population.     

A comparison of Demirjian's four dental development methods for forensic age assessment

The aim of this study was to determine the comparative accuracy of Demirjian's four dental development methods for forensic age estimation in the Western Australian population. A sample comprising 143 individuals aged 4.6 to 14.5 years were assessed using Demirjian's four methods for dental development (original 7-tooth: M(2), M(1), PM(2), PM(1), C, I(2), and I(1); revised 7-tooth: M(2), M(1), PM(2), PM(1), C, I(2), and I(1); 4-tooth: M(2), M(1), PM(2), and PM(1); and an alternate 4-tooth: M(2), PM(2), PM(1), and I(1)). When comparing all four methods, the 4-tooth method overestimated age in both males and females by 0.04 and 0.25 years, respectively. The original 7-tooth was least accurate for males, while the original 7-tooth, the revised 7-tooth, and the alternate 4-tooth were unsuitable for females. Therefore, we recommend the 4-tooth method to be used for forensic age estimation in Western Australian males and females, as it has the lowest overall mean deviation and the highest accuracy.