OBJECTIVES: To examine the reliability and accuracy of Walker's model for estimating the sex of Han adults in western China by using cranium three-dimensional (3D) CT reconstruction, and to study the suitable cranial sex estimation model for Han people in western China. METHODS: A total of 576 cranial CT 3D reconstructed images from Hanzhong Hospital in Shaanxi Province from 2017 to 2021 were collected. These images were divided into the experimental group with 486 samples and the validation group with 90 samples. Walker's model was used by observer 1 to estimate the sex of experimental group samples. The logistic function applicable to Han people in western China was corrected by observer 1. The 90 samples in the validation group were scored and substituted into the modified logistic function to complete the back substitution test by observer 1, 2 and 3. RESULTS: The accuracy of sex estimation of Han adults in western China was 63.2%-77.2% by applying Walker's model. The accuracy of modified logistic function was 82.9%. The accuracy of sex estimation through back substitution test by 3 observers was 75.6%-91.1%, with a Kappa value of 0.689 (P<0.05) for inter-observer consistency and 0.874 (P<0.05) for intra-observer consistency. CONCLUSIONS There are great differences in bone characteristics among people from different regions. The modified logistic function can achieve higher accuracy in Han adults in western China.
Humans ; Adult ; Reproducibility of Results ; Sex Determination by Skeleton/methods* ; Forensic Anthropology ; Skull/anatomy & histology* ; Imaging, Three-Dimensional ; China ; Tomography, X-Ray Computed

OBJECTIVES: To find the appropriate method for age estimation for different ages and sexes. METHODS: The costal cartilage, sternum and pubic symphysis of 91 unknowns from 2000 to 2020 from the Forensic Department of the Criminal Investigation Team of Shanghai Public Security Bureau were collected. Costal cartilage, sternal and pubic symphysis inferences were used to estimate the age, and the consistency between the estimated results and the actual physiological age of the unknowns was tested. The accuracy of age estimation of different samples was compared, and the relationship between accuracy and age and sex was analyzed. RESULTS: Using the costal cartilage method, the inference errors of males, females and the whole population under 40 years old were (0.608±2.298) years, (0.429±1.867) years and (0.493±2.040) years, while those over 40 years old were (-1.707±3.770) years, (-3.286±4.078) years and (-2.625±4.029) years. The differences between different age groups in these three populations were statistically significant (P<0.05). Using the sternum method, the inference errors of males and females under the age of 40 were (0.921±3.019) years and (0.452±1.451) years, while those over the age of 40 were (-5.903±5.088) years and (-1.429±2.227) years. The differences between different age groups in males and females were statistically significant (P<0.05). Using the pubic symphysis method, the inference errors of males and females under 40 years old were (-0.204±1.876) years and (0.238±2.477) years, while those over 40 years old were (1.500±2.156) years and (-2.643±4.270) years. The differences between different age groups in males and females were statistically significant (P<0.05). Using the sternum method and pubic symphysis method for age estimation of over 40 years old, the difference between different sexes was statistically significant (P<0.05). CONCLUSIONS All three methods of age estimation are stable and effective and more accurate for people under 40 years old. For age estimation of unknowns over 40 years old, the pubic symphysis method is preferred in males and the sternum method is preferred in females.
Adult ; Age Determination by Skeleton/methods* ; Child, Preschool ; China ; Female ; Forensic Anthropology/methods* ; Forensic Medicine ; Humans ; Infant ; Male ; Pubic Symphysis/anatomy & histology*

Age estimation from skeletal remains is an important step in forensic biological identification. The main objective of this study is to develop an age estimation equation for the Thai population from vertebral osteophytes. Each vertebra in the cervical, thoracic and lumbar segments was scored for degree of osteophyte formation. Classification was carried out in accordance with the criteria established by Snodgrass and Watanabe, and used a new modified score of the length of vertebral osteophyte for age estimation. The sample included 400 individuals (262 males, 138 females) ranging in age from 22 to 97 years. A sample of Thai vertebral columns was used, the columns being divided into the following groups of vertebrae: cervical (C2–C7), thoracic (T1–T12), and lumbar (L1–L5). Each vertebra was scored for the degree of osteophyte formation and the accumulated data was analyzed statistically. Correlation coefficients and R-squared from mean in lumbar vertebrae for females of criteria established by the method of Snodgrass and Watanabe, the new modified score by length of vertebral osteophytes were 0.801 and 0.642 (P<0.01); 0.755 and 0.57 (P<0.01); 0.786 and 0.618 (P<0.01), respectively. This study presents all 23 subcategories (C2–L5) of the vertebrae to apply in real situations, showing all age estimation equations for males, females and combined sexes of unknown sex. One application of this study is age estimation when dealing with forensic cases in the Thai population.
Asian Continental Ancestry Group ; Classification ; Female ; Forensic Anthropology ; Forensic Sciences ; Humans ; Lumbar Vertebrae ; Male ; Methods ; Osteophyte ; Research Design ; Spine ; Thailand

Objective Logistic regression method was used to establish a multiple regression sex discriminant function to discriminate the complete skull model and the incomplete skull model without frontal bone, occipital bone and mandible of Uygur adults in Turpan, Xinjiang. Methods A total of 117 （60 male and 57 female） three-dimensional skull models were collected by CT. Sixteen cranial measurement indexes were measured and calculated by computer software. The multivariate regression sex discriminant function was established with Logistic regression method and retrospectively tested. Results Among the 16 measurement indexes, except for nose width （x₇） and maximum frontal breadth （x₁₃）, the remaining 14 indexes had statistical significance of differences between male and female （P<0.05）. For the discriminant function of complete skull established by eyebrow arch convexity （x₄）, mastoid width （x₆）, maximum cranial length （x₁₂）, cranial base length （x₁₅）, cranial circumference （x₁₆）, the male and female discrimination accuracy was 90.0% and 94.7%, respectively. For the sex discriminant function of incomplete skull without frontal bone established by mandibular angle width （x₁₀）, mandibular height （x₁₁） and cranial circumference （x₁₆）, the discrimination accuracy of male and female was 85.0% and 84.2%, respectively. For the sex discriminant function of incomplete skull without occipital bone established by the index of eyebrow arch convexity （x₄）, the discrimination accuracy of male and female was 80.0% and 73.7%, respectively. For the sex discriminant function of incomplete skull without mandible established by frontal chord （x₅） and occipital protrusion angle （x₉）, the discrimination accuracy of male and female was 85.0% and 78.9%, respectively. Conclusion The computer software and system developed in our study can achieve sex discrimination of complete skulls and incomplete skulls without frontal bone, occipital bone or mandible.
Adult ; China ; Discriminant Analysis ; Ethnicity ; Female ; Forensic Anthropology ; Humans ; Imaging, Three-Dimensional ; Jaw/diagnostic imaging* ; Male ; Retrospective Studies ; Sex Characteristics ; Sex Determination by Skeleton/methods* ; Skull/diagnostic imaging* ; Tomography, X-Ray Computed/methods*

Objective To predict the pigmentation phenotypes of Chinese populations from different language families, analyze the differences and provide reference data for forensic anthropology and genetics. Methods The HIrisPlex-S multiplex amplification system with 41 loci related to pigmentation phenotypes was constructed in the laboratory, and 2 666 DNA samples of adult males of 17 populations from six language families, including Indo-European, Sino-Tibetan, Altaic, Hmong-Mien, Tai-Kadai and Austro-Asiatic language families distributed in different regions of China were genotyped. The pigmentation phenotype category of each individual was predicted using the online prediction system （https://HIrisPlex.erasmusmc.nl/）, and then the output data were statistically analyzed. Results About 1.92% of the individuals of Asian-European admixed populations from Indo-European and Altaic language families had blue eyes and 34.29% had brown or gold hair. The phenotypes of the color of eyes and hair of other populations had no significant difference, all individuals had brown eyes and black hair. There were differences in skin color of populations of different language families and geographical areas. The Indo-European language family had the lightest skin color, and the Austro-Asiatic language family had the darkest skin color; the southwestern minority populations had a darker skin color than populations in the plain areas. Conclusion The prediction results of pigmentation phenotype of Chinese populations are consistent with the perception of the appearance of each population, proving the reliability of the system. The color of eyes and hair are mainly related to ancestral components, while the skin color shows the differences between language families, and is closely related to geographical distribution of populations.
Adult ; Asian People/genetics* ; China ; Eye Color/genetics* ; Forensic Anthropology ; Forensic Genetics/methods* ; Humans ; Language ; Male ; Phenotype ; Polymorphism, Single Nucleotide ; Reproducibility of Results ; Skin Pigmentation/genetics*

While radioactive isotope analysis has proved to be a useful method in disciplines such as archaeology and forensic anthropology, more recently, radiocarbon dating has allowed for a more nuanced biological profile of human skeletal remains. Radiocarbon dating has been made possible by the above ground nuclear bomb test conducted in 1963, which raised the level of atmospheric radiocarbon concentration to almost twice the natural level. Because the annually measured tropospheric ¹⁴C concentrations are integrated into the bomb peak curve, the time of birth and death of an individual can be estimated by comparing the radiocarbon content of a skeletal sample to the bomb-curve value. In July 2017, about 1,000 skeletal remains were excavated at the construction site of Sokcho. For medico-legal purposes, we conducted anthropological and odontological examinations of all the human remains. We then conducted the radiocarbon analysis on seven femora (head and body portions), five mandibular teeth, and soil from the site through a request to the Korea Institute of Geoscience and Mineral Resources. The results demonstrated that the estimated year of birth or death was prior to the 1950s. Due to the diverse distribution of results, we deduced that the human remains were from the local mass grave. This study supports and suggests the use of radiocarbon dating more frequently in the analysis of human skeletal remains.
Archaeology ; Bombs ; Earth Sciences ; Forensic Anthropology ; Gangwon-do ; Humans ; Korea ; Methods ; Miners ; Parturition ; Radiometric Dating ; Soil ; Tooth

There have been many radiographic studies on age estimation that evaluate reduction in size of dental pulp cavity with secondary dentin formation. The Paewinsky method reported high accuracy in estimating ages by measuring the width of the pulp cavity in panoramic radiographs. The aim of this study was to evaluate the application of the Paewinsky method to digital periapical radiographs. This study was conducted on 103 cases that reported to the Section of Human Identification of the National Forensic Service. The age was calculated by applying the Paewinsky method that measures the root and pulp canal width at three points in a tooth. The estimation results were compared with those calculated by the Johanson method. When the Paewinsky models were applied to digital periapical radiographs, the errors were significantly greater as compared to the original study. The errors of the maxillary second premolar and mandibular lateral incisor were greater than those of the maxillary central incisor, lateral incisor, mandibular canine, and first premolar. Furthermore, errors of the age estimation models in level C were greater than those in levels A and B. This study could be a reference for the application of the Paewinsky method to digital periapical radiographs.
Age Determination by Teeth ; Bicuspid ; Dental Pulp Cavity ; Dentin, Secondary ; Forensic Anthropology ; Incisor ; Methods ; Radiography, Dental ; Tooth

Stature is one of the unique biological properties of a person, which can be used for identification of the individual. In this regard, statures are estimated for the unknown victims from crimes and disasters. However, the accuracy of estimates may be compromised by inappropriate methodologies and/or practices of stature estimation. Discussed in this study are the methodological issues related to the current practices of forensic anthropological stature estimation in Korea, followed by suggestions to enhance the accuracy of the stature estimates. Summaries of forensic anthropological examinations for 560 skeletal remains, which were conducted at the National Forensic Service (NFS), were reviewed. Mr. Yoo Byung-eun's case is utilized as an example of the NFS's practices. To estimate Mr. Yoo's stature, Trotter's (1970) femur equation was applied even though the fibula equation of a lower standard error was available. In his case report, the standard error associated with the equation (±3.8 cm) was interpreted as an ‘error range’, which gave a hasty impression that the prediction interval is that narrow. Also, stature shrinkage by aging was not considered, so the estimated stature in Mr. Yoo's case report should be regarded as his maximum living stature, rather than his stature-at-death. Lastly, applying Trotter's (1970) White female equations to Korean female remains is likely to underestimate their statures. The anatomical method will enhance the accuracy of stature estimates. However, in cases that the anatomical method is not feasible, the mathematical method based on Korean samples should be considered. Since 1980's, effort has been made to generate stature estimation equations using Korean samples. Applying the equations based on Korean samples to Korean skeletal remains will enhance the accuracy of the stature estimates, which will eventually increase the likelihood of successful identification of the unknowns.
Aging ; Crime ; Disasters ; Female ; Femur ; Fibula ; Forensic Anthropology ; Humans ; Korea* ; Methods

OBJECTIVES: To promote the further research on body stature estimation and the innovative applications based on the distances between the anatomical landmarks on body torso surface. METHODS: A specification for the collection of distances between the anatomical landmarks on body torso surface was established. The data of 933 cases of adult population in Yangtze River Delta region were collected. Multiple linear regression method was used to statistical analyse and establish the regression equation of stature estimation. RESULTS: A regression equation about 5 variables including gender （x₁）, cervical vertebrae-coccyx line （x₂）, sterna-pubis line （x₃）, distance between acromion and iliospinale anterius （x₄） and shoulder breadth （x₅）, and stature （y） was established, y=105.406+5.414 x₁+0.436 x₂+0.286 x₃+0.225 x₄+ 0.193 x₅. CONCLUSIONS The method is suitable for the rapid, simple and accurate estimation of stature for the forensic experts.
Adult ; Body Height ; Bone and Bones/anatomy & histology* ; Cervical Vertebrae/anatomy & histology* ; Female ; Forensic Anthropology/methods* ; Humans ; Linear Models ; Male ; Regression Analysis ; Torso/anatomy & histology*

Individual identification by measuring the human skeleton is an important research in the field of forensic anthropology. Computed tomography （CT） technology can provide high-resolution image of skeleton. Skeleton image can be reformed by software in the post-processing workstation. Different skeleton measurement indexes of anthropology, such as diameter, angle, area and volume, can be measured on section and reformative images. Measurement process is barely affected by human factors. This paper reviews the literatures at home and abroad about the application of measuring skeleton by CT in forensic anthropology research for individual identification in four aspects, including sex determination, height infer, facial soft tissue thickness measurement and age estimation. The major technology and the application of CT in forensic anthropology research are compared and discussed, respectively.
Age Determination by Skeleton ; Bone and Bones/diagnostic imaging* ; Forensic Anthropology/trends* ; Humans ; Sex Determination Analysis ; Software ; Tomography, X-Ray Computed/methods*