Quantitative and qualitative evaluation on the accuracy of three intraoral scanners for human identification in forensic odontology / 대한해부학회지

The purpose of this study was to analyze the accuracy of intra oral scanner (IOS) to confirm the applicability of IOS for the recording and analysis of tooth morphology in forensics. The less damaged mandible specimen with many teeth remaining was scanned three times using three types of intraoral scanners (CS3600, i500, and Trios3). For quantitative comparisons of the scanned images produced by these intraoral scanners, root mean square (RMS) values were computed using a three-dimensional analysis program and a one-way ANOVA was conducted with Tukey HSD (honestly significant difference) as a post-hoc analysis (α=0.05). The repeatability of the full scan data was highest with the i500 (0.14±0.03 mm), and the post-hoc analysis confirmed significant differences between the CS3600 and the i500 outcomes (P-value=0.003). The repeatability of the partial scan data for the teeth in the mandible was highest with the i500 (0.08±0.02 mm), and the post-hoc analysis confirmed significant differences between the CS3600 and the i500 (P-value=0.016). The precision of the full scan data was highest with the i500 (0.16±0.01 mm) but the differences were not statistically significant (P-value=0.091). Meanwhile, the precision of the partial scan data for the teeth in the mandible was highest with the Trios3 (0.22±0.02 mm), but the differences were not statistically significant (P-value=0.762). Considering that the scanning of other areas of the oral cavity in addition to the teeth is important in forensic odontology, the i500 scanner appears to be the most appropriate intraoral scanner for human identification. However, as the scope of oral scanning is generally limited to teeth in the practice of dentistry, additional discussions of how to apply the IOS in forensic odontology are needed. Ultimately, the results here can contribute to the overall discussion of the forensic applicability dental data produced by intraoral scanners.

Principles of Archaeogenetics and the Current Trends of Ancient Genome Studies / 체질인류학회지

Archaeogenetics is an academic discipline that aims to establish scientific facts of human history by integrating ancient DNA analyses with archaeological and anthropological evidence. After ancient DNA research was initiated about 30 years ago, it has been innovated so rapidly that the range of analysis has been extended toward the whole genome sequence of ancient genomes in recent 10 years. By this development, researchers have been able to study in detail the origins and migration patterns of hominin species and ancient human populations by approaches of evolutionary genetics. This study has reviewed main principles of the archaeogenetic analysis and the current trends of ancient genome studies with recent achievements. While sampling techniques and statistical analyses have been improved, typical research methods have been established by the findings on hominins and ancient western Eurasia populations. Recently, archaeogenecists have been applying the methods to studying those in other geographical areas. Nonetheless, there is still the lack of ancient genome research about populations in Eastern Asia including the Korean peninsula. This review ultimately aims to predict possibilities and promise of future ancient genome studies of ancient Korean populations.

Analytical Review of the Forensic Anthropological Techniques for Stature Estimation in Korea / 체질인류학회지

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.

Paleopathological Studies of Infectious Disease: Examination of the Osteoarchaeological Research / 체질인류학회지

Reconstructing the impact of infectious disease on past populations is one of the main fields in paleopathological studies. The initial phase of paleopathology was descriptive, focusing on the identification and presence of disease in the past. However, currently paleopathological studies are moving toward probing questions about the larger picture of origin and transmission of disease agents. In this study, paleopathological studies of major infectious disease (i.e., tubuerculosis, treponemal disease and leprosy) were reviewed through osteoarcheological work published in American Journal of Physical Anthropology, International Journal of Osteoarchaeology, Journal of Archaeological Science and International Journal of Paleopathology from 1981 to 2017. A basic objective of this research was to examine many types of research in paleopathology and to characterize research trend in this field. As paleopathological studies becomes more abundant, the approaches to infectious disease have been increasingly specialized and interdisciplinary from 1980. Also, methodology used in paleopathology continues to evolve through the holistic approaches of molecular analysis, radiology and histopathology. Ultimately, this study reinforces the importance for retention of large-scale skeletal collections for paleopathological study in population perspective. In the near future, Korean paleopathology can contribute in the reconstructions of the history of disease and its effect on past human populations.

Cranial index in a modern people of Thai ancestry / 대한해부학회지

The present research aims to examine the cranial index in a modern people of Thai ancestry. Ultimately, this study will help to create a databank containing a cranial index for the classifications of the people from Asia. In this study, 185 modern crania of people of supposed Thai ancestry were examined. They were collected from the Department of Anatomy at Chulalongkorn University in Bangkok, Thailand. The maximum cranial length and breadth were measured using standard anthropometric instruments based on Martin's methods. The cranial index was calculated using the equation ([maximum cranial breadth/maximum cranial length]×100). The mean cranial indices for the male and female skulls examined were 81.81±4.23 and 82.99±4.37, respectively. The most common type of skull in the modern Thai people in this study was the brachycranic type with a frequency of 42.7%, followed by the mesocranic (27.03%) and hyperbrachycranic types (25.59%). The rarest type observed in this study was the dolichocranic type (4.32%). The present study provides valuable data pertaining to the cranial index in a modern Thai population and reveals that modern Thai males and females belong to the brachycranic group. The results of this study will be of forensic anthropological importance to populations in close proximity to the location where the skulls studied here were sourced.

Probable Cases of Scurvy in Subadults Crania from Archaeological Sites, South Korea / 체질인류학회지

In this study, the skeletal abnormalities associated with scurvy in subadults crania from three archaeological skeletal collections (Nukdo, Imdang, Yeanri), South Korea was analyzed to examine the prevalence and distribution of childhood scurvy of ancient Korea. For this, 30 subadults crania from the Nukdo, Imdang, Yeanri site were examined. Using criteria described by Ortner and Ericksen (1997) for identifying scurvy in skeletal material we evaluated the cranial skeleton of the subadults for evidence of abnormal porosity. All skeletal materials were macroscopically evaluated for pathological changes associated with scurvy. In results, lesions indicative of probable scurvy were observed in 22 individuals of 30 individuals. Based on the results, childhood disease relating to nutrition and metabolism in ancient Korea might have been widespread, along with scurvy. The results of the present study will be useful for understanding the health condition of the ancient Korean populations. Future work will add significantly to the larger picture of diet and disease within populations of ancient Korea.

Dental Pathologies in the Three Kingdoms Period Population from Imdang Site, Gyeongsan, Korea / 체질인류학회지

Dental pathology has the potential to provide insight into the interpretation of the health and life style of past population. In particular, dental pathologies are strongly correlated to subsistence pattern, diet habits and food-preparation techniques. For this reason, my studies have focused on analyses of dental diseases (e.g., caries, abscesses, ante-mortem tooth loss, enamel hypoplasia, dental attrition, and periodontal diseases). The purpose of this study is to investigate the prevalence of dental pathologies of the Imdang population dating to between A.D. 3rd and A.D. 7th centuries (Three Kingdoms Period). In this study, through a macroscopic observation of dental remains from 138 individuals of the Imdang site, the prevalence of caries, abscess and ante-mortem tooth loss was examined. The association between sex, age and the frequencies of pathology was analyzed by the Chi-square tests. The results showed that the frequency of dental pathologies was consistently low level in Imdang population. Caries prevalence in the Imdang population was higher in females (6.15%) that in males (4.89). Among dental pathologies, abscess prevalence (0.7%) was lowest in Imdang population. Meanwhile, AMTL prevalence was 10.81% in males and 3.8% in females. There is a statistically significant difference between the anterior teeth of males and females (p<0.05). This study revealed that the rate of dental caries, abscess and AMTL in the Three Kingdoms Period population was relatively low level. This study is the first report of the patterns of dental pathologies in the Three Kingdoms Period population. It is necessary to investigate more number of pathologic markers that needed for deeper understanding of the multi-faceted nature of dental pathologies of ancient populations.

A Study of Bilateral Asymmetry Pattern in the Eye Orbit and Nose of the Joseon Dynasty Skeletal Group Using Geometric Morphometrics / 체질인류학회지

In this study, the pattern of bilateral asymmetry in the eye orbit and nose of the Joseon Dynasty skeletal group was analyzed using geometric morphometrics. For this, 38 adult males and 38 adult females from the Joseon Dynasty skeletal group belonging to the 15(th) to early 20(th) centuries were examined. For geometric morphometric analysis, Procrustes superimposition was performed on 10 landmarks in both eye orbits and 7 nasal landmarks. The data were analyzed by multivariate analysis of variance with partial least square scores. In results, the lateral landmarks had more impact on the bilateral asymmetry in the eye orbit and nose than the center landmarks. The eye orbit and nose on the right side of the face seemed bigger than those of the left side, while the direction of asymmetry in the eye orbit and nose was different. The correlation between asymmetry patterns in the eye orbit and nose were statistically significant (p<0.01). The results of this study will be useful for examining causes of bilateral asymmetry in the eye orbits and noses of the Korean population.

Harris lines observed in human skeletons of Joseon Dynasty, Korea / 대한해부학회지

The Harris line (HL), caused by bone-growth arrest and manifesting on X-rays as a radiopaque transverse line in the metaphysis of the long bones, is an indicator reflecting stress conditions such as disease or malnutrition. HL frequency has been assumed to differ between pre-modern and modern societies, as reflective of increased caloric intake and overall nutritional improvements attendant on industrialization. To determine if such a change occurred in Korea, in the present study we compared the respective HL statuses in medieval Joseon and modern Korean population samples. HLs were found in 39.4% (28/71) of the Joseon Koreans. Whereas only 27.5% (11/40) of the males showed an HL, fully 54.8% (17/31) of the females exhibited it. Notably, HLs were observed in only 16.4% (35/213) of the modern Koreans; more remarkably still, the HL rate was almost the same between the sexes, 16.7% (20/120) for the males and 16.1% (15/93) for the females. The HL frequency was much higher in the Joseon Koreans than in their modern counterparts, reflecting the improvement of nutritional status that had been achieved in the course of South Korea's modernization. This HL-frequency decrease was much more obvious in the female populations. The higher HL frequency among the Joseon females might reflect the relatively poor nutritional condition of females in pre-modern Korean society.

Biomechanical Properties of Femoral Diaphyseal Cross-sectional Shape from the Eunpyeong Population / 체질인류학회지

Long bone diaphyseal cross-sectional shape as a primary measure of biomechanical loading has attracted much attention in physical anthropology. Especially, lower limb bones have been widely used to reconstruct the mobility pattern of the past population. In this research, the cross-sectional size of the femoral shaft was investigated for the human skeletal remains excavated from the Eunpyeong site, dating the period spanning from the mid-15th to the early 20th centuries. The purpose of this research is to examine and report the biomechanical characteristics of the past populations living during Joseon Dynasty period. The results showed that Eunpyeong population was grouped into the 'platymeric category (i.e., platymeric index below 84.9). Females were more platymeric (i.e., more laterally flattened) than males and the sexual dimorphism was statistically significant. In addition, the samples of Eunpyeong site showed a relatively lower pilasteric index (i.e., more round) compared to the populations reported in other studies. The results of this research provide an insight to shed light on the ecological environments, subsistence strategies, and life styles of the past populations. Yet, for more detailed interpretation, it appears necessary to take into account other types of indicators for biomechanical stresses and accumulate more archaeological evidences.

Rethinking the Possibilities and Limitations of a Study on the Skeletal Markers Reconstructing the General Level of Physical Activity / 체질인류학회지

The reconstruction of activity and of work patterns has been approached by examinations of activity-related skeletal markers. Among several different methods, in particular, a number of anthropologists have widely applied the patterns of enthesopathies and degenerative joint disease in studies of past activity. The purpose of this study is to better understand and use these indicators in reconstructing the levels of physical activities of past populations. This review will provide information on the most recent anthropological research on the behavioral interpretation on degenerative joint disease and enthesopathies, to better use these indicators in understanding past populations. There are obvious limitations in using these markers, and it is necessary to consider them. Firstly, it is uncertain as to whether there are certain activities that are performed repetitively throughout their lives of those who lived in past civilizations. A second limitation involves the etiology of skeletal markers related to mechanical stress. There are multiple-factors, including genetic predisposition, sex, the aging process, and diet that may affect the way people practice a specific activity. Accordingly, this makes it difficult to evaluate the underlying etiological factors and their roles in activity-related skeletal changes. In conclusion, to circumvent these limitations, the use of multiple skeletal markers together in studies of the activities of past populations may enable to more reliable interpretations. However, to ensure more reliable interpretations, the validity of such combinations of makers should be challenged. Therefore, more work on the validity of activity-related markers is needed to clarify the activities that are responsible for the development in life of the features observable in skeletal populations. This type of research can contribute to the discussion of the use of activity-related skeletal markers in studies of behavioral interpretations with more certainty regarding which morphological characteristics are responses to physical activity and mechanical loading as the pathogenesis of such characteristics.

Patterns of Linear Enamel Hypoplasias among Korean Skeletal Samples from the Joseon Dynasty Period / 체질인류학회지

Dental linear enamel hypoplasia (LEH) is probably one of the most widely used developmental stress indicators among all known skeletal stress indicators. This research examined LEH on the permanent anterior teeth of 160 human skeletal remains from the Joseon Dynasty period. The purpose of this investigation is to understand the characteristics of the developmental stresses experienced by the people of the Joseon period by analyzing the patterns of LEH incidences. The skeletal remains analyzed for this research were excavated during an archaeological investigation at a construction site in Eunpyeong-gu, Seoul, South Korea. Eunpyeong site is estimated to date from the late 15th century to the late 19th century based on the burial type and goods discovered within the graves. Of all the skeletal remains found at this site, 160 individual specimens with at least one of the permanent anterior teeth constituted the sample of the study. Information regarding each individual specimen's sex, age at death, and burial type was collected by the standardized methods. The prevalence and number of LEH by tooth type, and the number of LEH by sex, by burial type, and by age at death were analyzed. Mandibular canines were the most frequently affected teeth, maxillary canines coming next in the occurrence of LEH, and the third turned out to be the maxillary incisors. This result generally agrees with the findings from previous studies. When number of LEH by sex was compared, there was no consistent difference by sex which also agrees with the findings of previous studies. Although specimens from lime-mortar burials tended to have less number of LEH then those from earth-pit burials, a probable indication of the socioeconomic status effect on the formation of LEH, the result was not very pronounced. No obvious association between the number of LEH and age at death was found, either. Finally the results from this study were compared with those reported by other researches on LEH worldwide. Although preliminary in its level of analysis, this study is the first report of the patterns of LEH of a skeletal population of Korea. With more studies of human skeletal remains from the past, it is hoped, physical anthropology can contribute to the understanding of the past life of the Korean people.