Histological assessment of gestational age in human embryos and fetuses

A light microscopic study performed on 760 human fetuses allows us to define several stages in their visceral development and to relate these to gestational age. The histological examination of most viscera, such as the central nervous system, is useless when the tissue preservation is poor. Nevertheless, three organs may still be studied in macerated fetuses: the lungs (where different glandular, canalar, and alveolar stages of development are evident), the kidneys (where the respective numbers of rows of primitive glomeruli and of generations of mature glomeruli vary after week 22), and the adrenal glands (where neuroblastic nests are normally found between weeks 7 and 26 of gestation). It is important to compare the degree of histological maturation with the clinical, macroscopic, and radiologic data in order to define the profile of maturation proper to each human fetus.     

Limits of the Lamendin method in age determination.

This study shows that epithelial attachment level, used as age determination criterion in Lamendin's method, is not reliable for adults of either sex above the age of 49 years with periodontal diseases in any quadrant. The underestimation of calculated age increases from 7 to 19 years with chronological age. On the other hand, the present paper confirms the pertinence of dentin translucency as an age indicator in Lamendin's method.     

Radiographic survey of third molar development in relation to chronological age among Japanese juveniles

The aim of the present study was to establish Japanese reference material on the third molar development of Japanese juveniles for forensic application. Observations were performed on the orthopantomograms of 1282 Japanese patients between the ages of 14.0 and 24.0 years. Demirjian formation stages of the maxillary and mandibular third molars were recorded for chronological evaluation of wisdom teeth and applied for further statistical analysis. Statistically significant differences were noted between the upper and lower jaws and genders. Accordingly, males achieved root developmental grades earlier than females. We assessed the mean ages for all formation grades and predicted the probability that a Japanese juvenile would be older than the relevant ages of 14, 16, and 20 as defined by Japanese Juvenile Law. We determined the likelihood that a Japanese youth is older than the relevant age of 18 as defined by legislation in the United States.     

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.     

青少年骨龄鉴定及其相关问题

本文综述了骨龄研究和应用历史,以及骨龄评测的新方法和新技术,讨论了骨骼发育的影响因素、骨龄标准时效性、骨龄评测部位选择及法医骨龄鉴定等相关问题。     

The core technique in the determination of age at death of skeletons.

This study proposed an histological method of estimating age at death in skeletons that uses a 0.4-cm-diameter core of cortical bone. Age-estimating regression equations were generated from data obtained from the analysis of bone cores taken from femurs, tibiae, humeri, and ulnas of cadavers. When the regression equations generated in this study were applied to eight forensic science cases, accurate ages at death were estimated.     

Fetal visceral maturation: a useful contribution to gestational age estimation in human fetuses

With regard to the law, estimating fetal age is essential to assess viability (after 20 weeks according to the WHO) and the proposed methods generally use long bone measurements. Here, we evaluated the accuracy of soft tissue maturational stage and compared it with long bone measurements. First, eight kinds of tissues or organs from 448 fetuses with known medical history were studied (macroscopically or histologically). We clearly demonstrated that adrenal glands and skin were very good age indicators, because some characteristics appeared only after 20 weeks. We established a linear regression with a 95% confidence interval of +/- 2.9 weeks. Second, we applied our original formula using femur measurement and we combined soft tissues and bones in a multiparametric regression. The confidence interval was reduced to +/- 2.5 weeks. We conclude that the pathologist must use both histological and anthropometric data to determine fetal age as accurately as possible.     

Significance of the ear in the determination of age

The morphology of human ear conch is said to be rather individual, but a perfect person-identification by this mean is not possible. It is demonstrated by photographs-made in a 15 years' interval-that ear conch and auricular area can be typically marked by proceeding age and specific diseases.     

Development of the femur--implications for age and sex determination

Growth of four variables of the femur (diapyseal length, diaphyseal length plus distal epiphysis, maximum length and vertical diameter of the head) was analyzed by polynomial regression for the purpose of evaluating its significance and capacity for age and sex determination throughout the entire life continuum. Materials included in analysis consisted of 346 specimens ranging from birth to 97 years of age from five documented osteological collections of Western European descent. Linear growth was displayed by each of the four variables. Significant sexual dimorphism was identified in two of the femoral measurements, including maximum length and vertical diameter of the head, from age 15 onward. These results indicate that the two variables may be of use in the determination of sex in sex determination from that age onward. Strong correlation coefficients were identified between femoral size and age for each of the four metric variables. These results indicate that any of the femoral measurements is likely to serve as a useful source to estimate sub-adult age in both archaeological and forensic samples.     

Morphometric analysis of the dental pulp chamber as a method of age determination in humans.

Eighty bite-wing radiographs from 40 female and 40 male patients were selected from the patient record system at the University of Texas Dental School at San Antonio, Texas. All samples were equally divided into four age groups, with a range from 15 to 55 years of age. The lower right first permanent molar tooth was chosen as the representative tooth for measuring the maximum height and width of the pulp chamber. The reproducibility of the method was checked by repeating all measurements on two different occasions. Regression analysis indicates that the height and width of the pulp chamber were negatively correlated with age (height r = -0.376 and width r = -0.125). The coefficient of determination (r2) for pulp chamber height and width were 0.123 and 0.058, respectively. This indicates that although there appears to be a definite relationship between the age of an individual and the height and width of the dental pulp chamber, these measures cannot be used as a reliable method of age determination.     

Dental age estimation from the developmental stage of the third molars in western Chinese population

The purpose of this study is to provide reference data about estimating dental age from third molars of the western Chinese population for comparing with other populations and being applied to the age estimation of western Chinese juveniles and adolescents. A total of 2078 digital panoramic radiographs of 989 male and 1089 female Chinese subjects aged between 5 and 23 years were examined. The mineralization status of the third molars was assessed using the formation stages described by Demirjian et al. with two modifications. The results showed that the development of third molars in the western Chinese population was likely to begin at age 5 in both males and females. The third molars 28 and 48 showed significantly higher frequency in females than in males. The third molars 18 in the stage 1, 38 in the stages 1, A and G, and 48 in the stage H showed significantly older average age in females than in males. The Demirjian's stages C and D could be used as a reference stage to determine dichotomously whether a western Chinese is more likely to be under or above age 14 or 16, respectively. This study provided reference data for the age estimation of western Chinese juveniles and adolescents by the mineralization stages of the third molar. Apart from forensic age determination in living subjects, the presented reference data can also be used for age estimations of unidentified corpses and skeletons.     

Identification and determination of age of needle tracks in human skin (author's transl)]

Examination of enzymic activities and histochemical reactions on needle pricks can be used to determine the age of micro-injuries with sufficient exactness. Well preserved skin shows patterns of enzymes which also appear with other skin injuries and which were described in detail especially by Raekallio (1970, 1972). In autolytical changes of the skin the adenosinetriphosphatase-reaction is still reliable and can be successfully estimated. If one has sufficient experience it is possible to fairly exactly estimate the age of an injury within the first hour after the injury by preparation of the adenosinetriphosphatase-reaction. If the times of injections are known one frequently succeeds in determining the time of death by exactly determining the age of the injury. In legal expertises the histochemical reactions can rightly be regarded as useful indications of a certain age of the injury. But they do not allow an exact estimate "beyond a reasonable doubt".     

Intravital acellular hemolysis of extravascular erythrocytes. An experimental contribution to the determination of wound age

The time-dependent acellular, destructive changes in erythrocytes was investigated in rabbits by subcutaneous, intraperitoneal, and subdural implantation of blood-filled diffusion chambers with 0.45 micron pores. The animals were killed at various intervals after implantation (7-24 h), and the erythrocytes in the capsules were examined by light and electron microscopy. The findings were quantified by counting 100 cells per preparation under the light microscope; changes in both matrix and membrane structure were recorded. Matrix changes and membrane variants were specified by electron microscopy. Time-dependent changes in erythrocyte matrix and membrane were established, which occurred at the various localizations in an identical sequence, but with different time intervals. The destructive changes were: an increase in loss of matrix, increase in membrane permeability, and decrease in membrane stability. The physiologic bases of and the conclusions for wound timing were discussed.     

Racial variation in the sternal extremity of the rib and its effect on age determination

Most research on the aging process in the skeleton has not considered or elaborated differences that may exist between the races. Thus, techniques developed for the estimation of age assume that the racial background of the standards is compatible with the specimens to be assessed. However, racial differences in areas such as skeletal growth and bone density have been reported, along with specific variations in the aging process, in the ribs of disparate populations. The present investigation examines metamorphosis in the sternal ribs of American blacks (N = 53 males, N = 20 females), and tests the application of age estimation standards developed by the authors from a white population. All specimens were obtained from medical examiner's cases of known age, sex, and race. Although the sample was limited in both quantity and age range, analysis of the data revealed racial differences in both rate and pattern of metamorphosis. Statistical analysis showed that the calculated mean age per phase for black ribs was nearly identical to whites in Phases 1 through 4 or until the mean age of 28 years. By the early 30s, differences in morphology and their chronological association with the aging process became apparent and increased with age in both sexes. Blacks were consistently overaged from 3 to 10 years in Phases 5 through 7. Therefore, it was concluded that biological differences between these populations do exist and can affect age estimation from the rib. Social factors may also be involved, but they cannot be demonstrated from the available data. While the degree of interracial variation does not require completely new standards, the authors have suggested specific modifications of the white standards for use on black specimens.     

A new method of age determination by age-related changes in the hand bone

An anthropological method designed for determining the age is under discussion; it is based on the point-evaluation of age-related changes observed in the hand bones by X-Ray, i.e. osteophytes, osteoporosis, osteosclerosis and joint deformations. The method was made use of to elaborate a new modified point-based assessment of the above changes in the hand bones with respect to their severity.     

Roentgen image of the hand as a principle for age determination in adolescents

Determination of age can be necessary in cases of juvenile offenders. We studied the relation between the skeletal development of the hand and wrist and the age, using diagnostic methods of orthodontics. An evaluation of 1109 X-ray pictures of the hand and wrist of boys and girls with an age from 9-18 years showed that there is a stochastic correlation between age and certain stages of skeletal development. Skeletal development is influenced by sex and ethnological factors.     

Individual age determination using growth rings in the cementum of buried human teeth

Incremental lines of the dental cementum were used for individual age determination in 102 teeth. 66 of them come from different historic periods, 15 teeth were cremated. 36 modern teeth of known age were use as controls. The incremental lines were investigated by use of 100 microns thin cross-sections of the root. Age determination by this method was possible in every tooth, independent of incinaration of various burial conditions. The individual age was determined by adding the mean value of the repeatedly counted incremental lines to the sex-specific eruption age of the tooth in question. Since average deviation from known age is +/- 3.23 years only, counting the incremental lines represent a very advantageous, quantitative method for individual age determination.