Assessment of differences in mechanical properties and thickness of temporal and occipital bones and correlation with age in Japanese forensic samples.

The mechanical properties and thickness of adult temporal and occipital bones were examined in modern Japanese forensic samples. Cranial bones were obtained from 293 Japanese corpses (179 men and 114 women). During autopsy, left temporal (LT), right temporal (RT), and occipital (O) bone samples were extracted from each skull. Sample thickness (ST) was measured using multidetector computed tomographic imaging. The fracture load (FL) of each sample was measured by a bending test, in which the flexural strength (FS) was calculated. The FL and ST values for O were significantly greater compared with those of the LT and RT bones. The temporal bones were thinner compared with other parts of the skull and at greater risk for fracture. There is a need to take precautions to prevent temporal bone fractures. There were no significant differences in any of the values between LT and RT, indicating bilateral symmetry of the temporal bones. There were significant negative correlations between age and the FL and FS values for all sites in both sexes, except for O in the male samples, suggesting that older individuals are at increased risk for fractures. No significant correlations were observed between age and ST values in any of the samples. There were significantly positive correlations between FL and ST values at all sites regardless of sex.

Characteristics of indoor and outdoor fatal hypothermia cases in Chiba, Japan.

In forensic medicine, hypothermia is a frequently encountered cause of death, and this characteristic provides public health information to prevent similar deaths in the future. Previous studies revealed regional differences in hypothermia occurrence (indoors or outdoors). However, to our knowledge, no recent studies in Japan have directly compared the characteristics of indoor- and outdoor-onset cases based on forensic autopsy reports. Hence, this study aimed to determine the characteristics and risks of unexpected hypothermia-related death. It included 218 cases from the Chiba Prefecture, Japan, wherein forensic autopsies were performed and hypothermia was diagnosed; these cases were categorized into indoor- and outdoor-onset cases, and their characteristics were examined. The results showed no significant differences between the two groups in relation to the age of onset or residential environment (i.e., the presence or absence of cohabitants). The outdoor-onset group tended to have a higher incidence of dementia. Regarding the causes of hypothermia, the indoor group had more internal causes (p < 0.0001), whereas the outdoor group had more primary and external causes (p < 0.0001 and p = 0.0029, respectively). The indoor group was more undressed than the outdoor group. Atypical antipsychotic components were predominantly detected in the blood in the outdoor group (p = 0.0077). The body mass index tended to be lower in the indoor group than in the outdoor group. Broadening public awareness of the present study findings may aid in developing preventative strategies for hypothermia based on the location of onset.

Mandibular torus thickness associated with age: Postmortem computed tomographic analysis.

Age estimation is an essential step in identifying human corpses. Several mandibular landmarks have been highlighted as skeletal sites for age estimation since aging causes morphological changes. Reports suggest that mandibular torus size may be associated with aging; however, thorough investigation has not been performed owing to the difficulty in measuring it. Therefore, this study aimed to determine the association between age and mandibular torus thickness using postmortem computed tomography data from Japanese corpses. This study included 2,792 corpses with mean (standard deviation) age of 58.0 (22.4) years (range, 0-101 years) and 67.6 % males. Further, 2,662 (95.3 %), 14 (0.5 %), 59 (2.1 %), and 57 (2.0 %) corpses were in the permanent, mixed, primary, and predental dentition periods, respectively. Multivariable analysis was performed to quantify the impact of age on mandibular torus thickness, adjusting for sex, height, weight, and occlusal contact status. The model also included an interaction term between age and occlusal status because of the potential effect modification by occlusion. Results of the multivariable regression analysis showed that mandibular torus thickness increased with age (the regression coefficients (95 % confidence interval) were 0.6 (0.2-1.0), 0.7 (0.3-1.0), 1.0 (0.6-1.4), 1.3 (0.9-1.7), 1.3 (0.8-1.8), and 1.1 (0.4-1.7) for age groups 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89 years, respectively), especially in males with occlusal contact. A significant association between mandibular torus thickness and age, modified by occlusal status and sex, was identified. Therefore, data regarding the thickness of the mandibular torus and occlusal status may be useful for age estimation in human corpses.

Lethal hemopericardium caused by infection of mitral annular calcification: An autopsy case report.

Mitral annular calcification (MAC) is a chronic and degenerative condition involving calcification of the mitral annulus. MAC is a risk factor for coronary artery disease, cardiovascular events, stroke, and cardiovascular death. However, patients with MAC are often asymptomatic. Herein, we present the first case of cardiac tamponade due to infection of MAC in forensic pathology. An 80-year-old woman was found in cardiopulmonary arrest shortly after experiencing fatigue. She was transferred to a hospital, and despite chest compression and ventilation, she was pronounced dead due to no response. Postmortem computed tomography, autopsy, and histological examination showed MAC, abscess formation involving Gram-positive cocci on the MAC, and fistulation of the abscess into the intracardial pericardial cavities, resulting in a massive lethal hemopericardium.

Detection of diatoms in a case of mud aspiration at a coastal area.

The source of diatoms detected in non-drowned bodies have been attributed to postmortem invasion, contamination during autopsy or diatom testing, or "natural load." However, sand aspiration has not been reported as a source. Herein, we report an autopsy case in which diatoms were detected in a non-drowned human who had aspirated mud. A man in his 60 s was found dead at a harbor park in Japan. His whole body was covered with sand, including his face. A situational investigation suggested that he may have entered the sea. Autopsy revealed intratracheal mud, with no obvious findings indicating drowning, suggesting that he died from mud aspiration probably due to hypothermia or non-lethal ethanol intoxication. In the diatom test, 10-100 diatoms/g were detected in bilateral lung samples, which were similar to those found in the intraoral and intratracheal mud and the sand samples from around the discovery site and not similar to those found in the seawater samples. The diatoms in the stomach content exhibited an intermediate trend between those found in the sand and seawater. Therefore, careful qualitative and quantitative analyses are required to differentiate between true drowning and false-positives in non-drowning cases to determine the cause of death.

Usefulness of powdered crown of mandibular first premolars in birth year estimation by radiocarbon dating.

BACKGROUND: Radiocarbon (14C), whose levels increased in the atmosphere between 1955 and 1963, accumulates in the enamel of human teeth only during the process of tooth formation and has been applied to estimate the birth year of unidentified corpses. However, enamel isolation from teeth is time-consuming and labor-intensive. Therefore, this study aimed to estimate the birth year using 14C in the crown of a single mandibular first premolar tooth. MATERIALS AND METHODS: Fourteen mandibular first premolars collected from forensic autopsies were analyzed. For nine teeth, each tooth was cut longitudinally: half of the tooth was enamel, and the other half was crown (1). For the other five teeth, the entire crown was used (2). Thereafter, the 14C concentration in each tooth was measured using accelerator mass spectrometry. RESULTS: The absolute error between the actual date of birth (DOB) and the estimated DOB was within the range of 1.0-8.8 years in the enamel of five teeth and 0.1-4.0 years in the crown halves of seven teeth (1). For the five teeth with entire crowns, the absolute errors ranged between 0.3 and 3.0 years (2). CONCLUSION: The absolute error of 14C-based year of birth estimation using the powdered crown of the mandibular first premolar teeth ranged between 0.1 and 4.0 years. Our method, which involves pulverizing an entire crown, eliminates the need for the equipment, time, and labor associated with enamel isolation. Therefore, 14C dating using powdered crowns of mandibular premolars can be useful for birth year estimation.

Age estimation by palatal suture using modified Kamijo's method.

The present study aimed to investigate the correlation between palatal suture obliteration and age in modern Japanese and to develop an age estimation equation by modifying Kamijo's (1949) method. The subjects were 195 Japanese skeletal remains (155 males and 40 females) whose age and sex were known. First, obliteration score (OS) was obtained by measuring palatal suture obliteration from photographic images taken at the time of forensic autopsy, and the correlation with age was examined; no significant correlation was found in females. Second, the palatal sutures were divided into 14 sections, and each section was scored from 0 to 4 points according to the degree of the suture obliteration. Suture scores (SS) were then calculated for each of the four sutures, and the sum of the 14 scores (TSS: total suture score) was used to perform regression analysis for age. For male and all subjects (male and female), age significantly increased (p < 0.001) according to increment of SSs for all sutures. TSS has the highest regression coefficient (r = 0.540), and the lowest standard error of estimation (13.54 years) for all of the patients. The intra- and inter-observer agreement scoring showed high reliability. Validation study using the formulae showed a high percentage of correct responses (80 %). In conclusion, age estimation regression formula by palatal suture using modified Kamijo's method was established for Japanese population, and the study showed the formula might be valid for age estimation.

X-ray analytic microscopy with CT-guided sample extraction to analyze potential projectile fragments in a dead serow.

In forensic pathology, it is important to detect and recover as evidence residual metal particles and projectiles when evaluating potential gunshot wounds. This process can be challenging when the bullets are fragmented. This report presents our experience using multiple modalities to analyze the wound of an illegally killed Japanese serow (Capricornis crispus) found in a mountainous region without its head and hind limbs. We performed postmortem computed tomography (PMCT) and necropsy that showed a distant-range gunshot wound of the neck likely created by a centerfire rifle. A postmortem cut through the neck and absent head precluded a complete evaluation. To determine the composition of the metal-like fragments in the neck, sampling and metal analysis were performed in two ways. Samples extracted from the exposed wound surface without CT guidance were analyzed directly using inductively coupled plasma mass spectrometry (ICP-MS). Samples from the bone, muscles, and cervical cord extracted under CT guidance were analyzed using x-ray analytic microscopy (XGT-9000, HORIBA, Kyoto, Japan). In wound surface samples, silicon and iron were detected as the main components on ICP-MS, suggesting that the materials were gravel. The samples taken under CT guidance and analyzed with XGT-9000 revealed that the high-density CT areas were mainly composed of lead. Combining CT-guided sample extraction and XGT-9000 can be useful for retrieving true projectile fragments and avoiding the confusion created by erroneously sampling non-projectile surface materials.

Age estimation by evaluating median palatine suture closure using postmortem CT.

This study sought to develop an age-estimation formula to evaluate the extent of median palatine suture (MP) closure using postmortem computed tomographic (PMCT) images. The PMCT images of 634 Japanese subjects (mean age, 54.5 years; standard deviation [SD], 23.2 years) with known age and sex were examined. The degree of suture closure of the MP, anterior median palatine suture (AMP), and posterior median palatine suture (PMP) was measured and scored (suture closure score, SCS), and a single linear regression analysis was conducted with age at death. On the analysis, SCS of MP, AMP, and PMP showed a significant correlation with age (p < 0.001). The correlation coefficient of MP was higher (0.760, male; 0.803, female; and 0.779, total) than that of AMP (0.726, male; 0.745, female; and 0.735, total) or PMP (0.457, male; 0.630, female; and 0.549, total). The regression formula and standard error of estimation (SEE) of MP were calculated as Age = 100.95 × SCS + 20.51 (SEE 14.87 years) for male subjects, Age = 91.93 × SCS + 26.65 (SEE 14.12 years) for female subjects, and Age = 95.17 × SCS + 24.09 (SEE 14.59 years) for the total, respectively. In addition, another 50 Japanese subjects were randomly selected to validate the age-estimation formula. In this validation, the actual age of 36 subjects (72%) was within the estimated age ± SEE. This study showed that the age estimation formula using PMCT images of MPs was potentially useful for estimating the age of unidentified corpses.

Statistical analysis of biomechanical properties and size of the sternum and its fracture risk in a Japanese sample.

OBJECTIVE: Sternal fractures can have life-threatening complications. To understand chest injury mechanisms, sufficient data regarding the mechanical properties and structure of the sternum are required. The aim of this study was to examine the mechanical properties and size of the sternum in a Japanese forensic sample. MATERIALS AND METHODS: Sterna were obtained from 120 Japanese dead bodies of known age and sex. The sample thickness (ST) and the sample width (SW) were measured using a computed tomographic image. Three-point-bending tests were conducted using a three-point-bending apparatus to assess the fracture load (FL) of the sample. Then, the flexural strength (FS) was calculated and the natural logarithm of FL (ln FL) and FS (ln FS) were also calculated. RESULTS: The values of ST, ln FL, and ln FS for male samples were significantly greater than those for female samples. Both ln FL and ln FS had significant negative correlations with age regardless of sex; the Pearson product-moment correlation coefficients were larger for female samples than for male samples. Although age was significantly negatively correlated with SW in female samples, there was no significant correlation between age and SW in male samples. No significant correlations were found between age and ST regardless of sex. CONCLUSION: This is the first study to present quantitative data on the biomechanical properties of the sternum. Because of the smaller sternal strength of elderly women, it is especially important for them to avoid the risk of sternal fractures.

Identification, measurement, and evaluation of blood concentrations of insulin glargine and insulin lispro by UPLC-MS-MS in a dead body suspected of insulin overdose.

Insulin preparations, which are drug treatments for diabetes, cause fatal hypoglycemia when an overdose is administered. Cases of homicide and suicide using these preparations have been reported and are of great forensic interest. However, there are few reports assessing the postmortem concentration of insulin preparations, and it is often difficult to determine the cause of death. In the present study, we report a case of a suspected insulin glargine and insulin lispro overdose for suicide. A woman in her 30s had a history of mental illness and diabetes. The day before her death, she reported to her boyfriend that she had taken large doses of insulin preparations and prescription drugs. An autopsy revealed no fatal injuries or lesions. Drug screening tests revealed several prescription drugs, none of which showed toxic concentrations. Analysis using LC-MS/MS detected insulin glargine in the peripheral and cardiac blood at 429 µU/mL and 1362 µU/mL, respectively, whereas insulin lispro was detected in both the peripheral and cardiac blood at levels below the lower limit of quantification (LLOQ; <50 µU/mL). The cause of death was considered likely to be hypoglycemia caused by an overdose of insulin glargine. Insulin glargine is rapidly metabolized after subcutaneous administration and is rarely detected in the blood when used at therapeutic doses. There are no other reports on the quantification of insulin glargine parent compounds in postmortem samples, and this case provides important data on postmortem blood concentrations of insulin glargine intoxication.

Statistical analysis of the thickness and biomechanical properties of Japanese children's skulls.

OBJECTIVE: The structure and strength of a child's skull are important in accurately determining what and how external forces were applied when examining head injuries. The aims of this study were to measure skull thickness and strength in children, evaluate sex differences, and investigate the correlation between skull thickness and strength and age. MATERIALS AND METHODS: Skulls were obtained from 42 Japanese dead bodies under 20 years of age. During the autopsies, bone samples were taken from each skull. The length, width, and central thickness of the skulls were measured using calipers. Three-point bending tests were conducted, and bending load and displacement were recorded. Bending stress and bending strain were calculated, and Young's modulus, 0.2% proof stress, and maximum stress were obtained. RESULTS: In cases under 1.5 years old, 14 out of 46 male samples and 20 out of 40 female samples did not fracture during the three-point bending test, though no significant sex differences were detected. No significant differences in age, sample thickness, Young's modulus, 0.2% proof stress, or maximum stress were detected between the sexes. The sample thickness, Young's modulus, 0.2% proof stress, and maximum stress increased significantly and logarithmically with age (R2 = 0.761-0.899). Although age correlated with thickness, Young's modulus, and maximum stress more in females than in males, 0.2% proof stress correlated slightly better in males than in females. CONCLUSION: The skulls of preschool children, in particular, are thin, have low strength, and are at high risk of fracturing even with relatively small external forces. Unlike adults, no significant sex differences in skull thickness or strength were observed in children.

High titers of infectious SARS-CoV-2 in corpses of patients with COVID-19.

OBJECTIVES: The prolonged presence of infectious SARS-CoV-2 in deceased patients with COVID-19 has been reported. However, infectious virus titers have not been determined. Such information is important for public health, death investigation, and handling corpses. The aim of this study was to assess the level of SARS-CoV-2 infectivity in the corpses of patients with COVID-19. METHODS: We collected 11 nasopharyngeal swabs and 19 lung tissue specimens from 11 autopsy cases with COVID-19 in 2021. We then investigated the viral genomic copy number by real-time reverse transcription-polymerase chain reaction and infectious titers by cell culture and virus isolation. RESULTS: Infectious virus was present in six of 11 (55%) cases, four of 11 (36%) nasopharyngeal swabs, and nine of 19 (47%) lung specimens. The virus titers ranged from 6.00E + 01 plaque-forming units/ml to 2.09E + 06 plaque-forming units/g. In all cases in which an infectious virus was found, the time from death to discovery was within 1 day and the longest postmortem interval was 13 days. CONCLUSION: The corpses of patients with COVID-19 may have high titers of infectious virus after a long postmortem interval (up to 13 days). Therefore, appropriate infection control measures must be taken when handling corpses.

Occupational accidental injury deaths in Tokyo and Chiba prefectures, Japan: A 10-year study (2011-2020) of forensic institute evaluations.

Occupational accidental injury deaths (OAIDs) are a major social problem, and the analysis of individual cases is important for developing injury prevention measures. In this study, OAIDs with autopsies performed at forensic facilities in the metropolitan area of Japan (Tokyo and Chiba prefectures) from 2011 to 2020 were reviewed. The epidemiological characteristics of these OAIDs (n = 136), which accounted for 13.5% of OAIDs reported in the region during the study period, were compared with those of non-occupational accidental injury deaths (non-OAID) cases (n = 3926). Among OAID cases, 134 (98.5%) were men and 13 (9.6%) were foreign-born workers, which was significantly more than in non-OAID cases (p < 0.001, respectively). OAIDs were most frequent in construction (39.0%) followed by the manufacturing category (21.3%). The percentage of OAIDs in workers aged 65 and over showed an increasing trend. Most accidents occurred just after the start of work or just before the workday ended, as well as during the peak months of the year. The most common type of accident was fall/crash from a height (25.0%), and the most common injury site was the chest; none of these cases were confirmed to have been wearing a safety belt properly. Among foreign-born workers, the most common type of accident was caught in/between. As the working population is expected to change in the future, and an increase in the number of older adults and foreign workers is expected, it is necessary to take preventive measures such as improving the work environment based on ergonomics and providing safety education.

Methamphetamine-related forensic autopsy cases in a Japanese prefecture over a 7-year period: Characteristics of deaths and blood concentrations.

Understanding the actual conditions of methamphetamine (MA)-related death is important from the perspectives of criminal justice and public health. In this report, we review 104 cases of MA-related death handled by our departments between January 2014 and December 2020. Based on information from police and autopsy examinations, we classified the cases into the following categories: "accidental intoxication" ("MA only" and "multiple drugs or alcohol"), "fatal disease" ("definitively MA-related," "possibly MA-related," and "unlikely MA-related"), "accident," "suicide," "homicide," and "undetermined." The total number and annual trends for each category and their respective femoral blood concentrations were investigated. "Fatal disease" was the most common category (48 cases), followed by "suicide" (25 cases), "accidental intoxication" (14 cases), and "accident" (11 cases). "Definitively MA-related" in which MA may have played a role in their onset or exacerbation accounted for the majority of "fatal disease": 12 cases of heart disease, 4 cases of aortic dissection, 12 cases of cerebral hemorrhage, and 4 cases of subarachnoid hemorrhage. Cases classified as "definitively MA-related" died with lower femoral blood concentrations of MA compared with "MA only." Cases with "fatal disease" might have been misdiagnosed as "death by natural causes" if a proper autopsy and toxicology examinations were not performed. In death investigations, it is necessary to keep in mind that there are some MA-related deaths, and efforts should be made to increase awareness about the risk of death in using this drug.

Relevance of diatom testing on closed organs of a drowned cadaver who died after receiving treatment for 10 days: A case report.

A male in his late adolescence fell into the sea and was found 50 min later with cardiopulmonary arrest. He was revived approximately 260 min after he drowned. Although he received several treatments, including venoarterial extracorporeal membrane oxygenation and continuous hemodiafiltration, he was clinically diagnosed with brain death. He died 10 days after the accident. The autopsy did not reveal any unremarkable findings other than those associated with post-resuscitation changes and medical treatment. The diatom test revealed 47.9, 311.6, and 577.5 diatom particles per gram from water, left lung, and right lung samples, respectively. No diatoms were detected in a 10 g liver sample, and 1 diatom was detected in each of approximately 12 g of bilateral kidney samples, which was different from the abundant species in the lung samples. The diatom test of the closed organs could be considered false negative for confirming drowning death since diatoms can also be detected in non-drowned cadavers on dry land. This suggests that diatoms might not reach the closed organs via circulation and that the diatom test of closed organ samples might no longer be necessary to confirm drowning deaths.

Stature estimation by semi-automatic measurements of 3D CT images of the femur.

Stature estimation is one of the most basic and important methods of personal identification. The long bones of the limbs provide the most accurate stature estimation, with the femur being one of the most useful. In all the previously reported methods of stature estimation using computed tomography (CT) images of the femur, laborious manual measurement was necessary. A semi-automatic bone measuring method can simplify this process, so we firstly reported a stature estimation process using semi-automatic bone measurement software equipped with artificial intelligence. Multiple measurements of femurs of adult Japanese cadavers were performed using automatic three-dimensional reconstructed CT images of femurs. After manually setting four points on the femur, an automatic measurement was acquired. The relationships between stature and five femoral measurements, with acceptable intraobserver and interobserver errors, were analyzed with single regression analysis using the standard error of the estimate (SEE) and the coefficient of determination (R2). The maximum length of the femur (MLF) provided the lowest SEE and the highest R2; the SEE and R2 in all cadavers, males and females, respectively, were 3.913 cm (R2 = 0.842), 3.664 cm (R2 = 0.705), and 3.456 cm (R2 = 0.686) for MLF on the right femur, and 3.837 cm (R2 = 0.848), 3.667 cm (R2 = 0.705), and 3.384 cm (R2 = 0.699) for MLF on the left femur. These results were non-inferior to those of previous reports regarding stature estimation using the MLF. Stature estimation with this simple and time-saving method would be useful in forensic medical practice.

Ropinirole involved in a fatal case: blood and urinary concentrations.

PURPOSE: Ropinirole is an antiparkinsonian  drug and has recently been suggested to be effective in amyotrophic lateral sclerosis. It is expected that ropinirole prescriptions will increase in the near future. However, the fatal concentration in blood is unclear at this time. Therefore, we report a fatal case involving ropinirole intoxication and discuss the fatal concentrations with reference to several autopsy cases involving ropinirole. METHODS: Ropinirole was quantified in femoral vein blood, cardiac blood, and urine from five autopsy cases in which ropinirole was detected by drug screening in our laboratory. One is a ropinirole intoxication case (this report) and the others  were non-intoxication cases. Their ropinirole concentrations were compared and discussed. RESULTS: The ropinirole concentration in this case was 100 ng/mL in femoral blood, 160 ng/mL in cardiac blood, and 1840 ng/mL in urine. The ropinirole concentrations in the four non-ropinirole poisoning cases were 7-35 ng/mL (mean: 24 ng/mL) in femoral blood, 13-100 ng/mL (mean: 60 ng/mL) in cardiac blood, and 140-1090 ng/mL (mean: 640 ng/mL) in urine. Cardiac/peripheral ratios were in the range of 1.6-2.1 (mean 1.8). CONCLUSIONS: There were no obvious signs of overdose, and the high cardiac/peripheral blood ratio suggested that postmortem redistribution may have occurred, but the  peripheral blood ropinirole concentration (100 ng/mL) was obviously higher than that reported in the previous fatal case of ropinirole poisoning (64 ng/mL). Based on these results, the cause of death in this case was considered to be shock and fatal arrhythmia due to ropinirole poisoning. This case provides important data on postmortem blood and urinary levels of ropinirole poisoning.

Validity of dental findings for identification by postmortem computed tomography.

Postmortem computed tomography (PMCT) images help identify individuals and extract information from corpses. PMCT may substitute for a standard examination when bodies are severely damaged or when resources are limited in a mass fatality incident. In such situations, the dental information revealed by PMCT has the potential to narrow down candidates for identification further. However, the validity of the dental findings obtained from PMCT images remains unclear. In this study, we investigated the validity of dental findings on PMCT images compared to regular dental examinations as the reference standard. We routinely collected PMCT images of 148 unidentified corpses and compared the dental findings of each tooth obtained from PMCT with those of a regular dental examination. The validity of dental findings of PMCT was measured by sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). We also evaluated the accuracy of dental findings per corpse using 32 teeth as the denominator. The dental findings with high sensitivity and high specificity were a present tooth (0.96 and 0.97), a missing tooth (0.97 and 0.97), pontic (0.92 and 1.00), a dental implant (1.00 and 1.00), and a root filling (0.94 and 0.99). The mean accuracy of the dental findings per corpse in PMCT was 95.6% (standard deviation: 6.9, minimum ≤ median ≤ maximum: 65.6 ≤ 100 ≤ 100). The number of corpses with 100% accuracy in the dental findings was 81 (54.7%). The information obtained in this study highlights the potential use of PMCT during human identification in several settings with limited resources, such as the number of specialists present and the condition of the corpses.

Carrion flies (Insecta: Diptera) found on human cadavers in Chiba prefecture, Honshu, Japan, with the first record of Fannia prisca from a human corpse.

Forensic entomology (FE) involves the collection and analysis of necrophagous insects and arthropods for postmortem interval estimation based on their growth and succession. In Japan, research on FE is limited, and the predominant species of necrophagous insects and their distribution have not been clarified. The present study aimed to clarify the actual situation of insects, targeting Diptera collected from human cadavers, in Chiba Prefecture. We targeted the cases for which specimens could be collected from forensic autopsies conducted at the Legal Medicine Department of Chiba University Graduate School of Medicine or from human bodies handled by the Chiba Police in 2019. We specifically chose cases from which adult insects could be bred. Fifty cases were applicable, and 47 cases were successful in rearing adult flies. Sixteen species of Diptera were identified: six species of Calliphoridae, four species of Sarcophagidae, and a few species of Fanniidae, Muscidae, Phoridae, Piophilidae, and Stratiomyidae. The most frequently observed species were Lucilia sericata (20 cases) and Chrysomya pinguis (18 cases). For the first time, globally, we recorded the presence of Fannia prisca in a human cadaver. In conclusion, this is the first report to reveal the presence of carrion flies in human death cases in Chiba Prefecture, Japan. Research in FE is important in the context of the Japanese natural and social environment since this can aid forensic investigations conducted by authorities.