Identification of unknown bodies by using CT images of frontal sinus

The aim of the study was to define a simple system for the identification of unknown bodies by using CT images of frontal sinus and to discuss whether it was worth to add measurements to the system or not. The system was including simple features as F (presence or absence of frontal sinus), S (intersinus and intrasinus septum) and S (scalloping), and named as FSS system. Measurements selected for the study were width, height, anteroposterior length, total width of two sinuses, the distance between the highest points of the two sinuses and the distance of each sinus to its maximum lateral limit. The study was conducted retrospectively on the paranasal CT scans of 100 cases (38 male and 62 female) who had no apparent sinonasal pathology. All the features and measurements were coded according to the system defined by the authors for each case and coded formulas were compared. At least 93% of the formulas could be eliminated for a case by using FSS system. The rate of success was increased to 98% by adding measurements. Contrary to objective criteria of FSS system, measurements were prone to bias. Therefore, in practice success rate would be expected to be lower than calculated. In the study population, instead of making 100 measurements, eliminating the most of the cases with FSS system and later discriminating the rest by pattern matching was seen logical.     

Sexual Dimorphism of Maxillary Sinus Dimensions Using Cone‐Beam Computed Tomography

Sex determination of unknown persons plays an important role in forensic medicine. Cone‐beam computed tomography (CBCT) is an excellent imaging modality for accurate measurement of maxillary sinus dimensions. This study aimed to evaluate whether maxillary sinus measurements on CBCT scans can be applied for sex determination. The width, length, and height of maxillary sinuses in CBCT images of 100 patients (50 males and 50 females) were measured. Student's t‐test and discriminant function analysis were used to compare differences in the measured parameters between males and females. The correct predictive accuracy rate of sex determination was 78% in females and 74% in males with overall accuracy of 76%. Based on discriminant analysis, the most pronounced variable in differentiation of sex groups was maxillary sinus height. This study suggests that maxillary sinus measurements can be valuable for sex determination in forensic investigation, especially for cases in which other traditional methods are not applicable.     

Photogrammetry vs CT Scan: Evaluation of Accuracy of a Low-Cost Three-Dimensional Acquisition Method for Forensic Facial Approximation

Photogrammetry is a three-dimensional acquisition method potentially applicable to the forensic field. This possibility requires the verification of its accuracy. In this study, 3D volumes of skulls are generated to compare the photogrammetry versus the CT scan. In order to provide eligible material to the photogrammetric software, photographs were captured at a distance of 30 cm from the skull placed on a support 1 m in height and illuminated with diffused laboratory ceiling artificial light. A Nikon Coolpix P7100 camera was used. Photographs capture common elements with the previous and the next photograph so as to allow the photogrammetric software to recognize these common points between photographs and create a 3D puzzle. The Zephyr Lite (3DFlow©) software was employed to register the 3D volume. CT-based skulls are taken as a metric reference. The photogrammetry-based skulls are then enlarged according to the measurements of some landmarks or Zygion and Zygion, the distance between end of nasal and base of nasal pyramid for frontal projection, and minimum breadth of the mandibular ramus for the right lateral projection. The accuracy of the photogrammetry is compared to that of the CT scan by measuring the 3D volumes of the skulls studied. Specific landmarks are used as reference points for the measures in both frontal and lateral views. Bland–Altman graph shows homogeneity. The mean difference (1.28 mm) indicates that the measurements taken on the photogrammetry-based skull tend to slightly overestimate compared with the measurements taken on the CT-based skull.     

Identification of group affinity from cross-sectional contours of the human midfacial skeleton using digital morphometrics and 3D laser scanning technology

Identifying group affinity from human crania is a long-standing problem in forensic and physical anthropology. Many craniofacial differences used in forensic skeletal identification are difficult to quantify, although certain measurements of the midfacial skeleton have shown high predictive value for group classifications. This study presents a new method for analyzing midfacial shape variation between different geographic groups. Three-dimensional laser scan models of 90 crania from three populations were used to obtain cross-sectional midfacial contours defined by three standard craniometric landmarks. Elliptic Fourier transforms of the contours were used to extract Fourier coefficients for statistical analysis. After cross-validation, discriminant functions based on the Fourier coefficients provided an average of 86% correct classifications for crania from the three groups. The high rate of accuracy of this method indicates its usefulness for identifying group affinities among human skeletal remains and demonstrates the advantages of digital 3D model-based analysis in forensic research.     

Sex determination using nonmetric characteristics of the mandible in Koreans

The mandible is the largest and hardest facial bone and retains its shape better than other bones in the forensic and physical anthropologic field. The mandible can be used to distinguish among ethnic groups and between sexes. We examined the morphological characteristics of the mandibles of 102 Koreans of either sex. Of 13 nonmetric items of the mandible, the characteristic that best allowed the sexes to be distinguished was the contour of the lower border of the mandible: rocker-shaped mandibles predominated in males (68.1%), whereas most females (84.6%) exhibited a straight mandible. In addition, the mental region was shaped differently between the sexes: the shape of the chin in most males was generally bilobate or square (91.7%), whereas the chin in females was either square (45.5%) or pointed (54.5%). In this study, the positive predict values of male and female were 92.5% and 73.7%, respectively. Therefore, the nonmetric method used to analyze the mandible in this study can be used for sex discrimination.     

骨骼CT三维重建图像性别判定和年龄推断研究

目的通过计算骨骼计算机断层扫描(Computed Tomography,CT)三维重建图像判定性别和推断年龄的准确率,评价利用骨骼CT三维重建图像判定性别和推断年龄的可行性。方法将法医人类学教材中性别判定和年龄推断的方法应用于539例骨骼CT三维重建图像样本,判定245例骨盆的性别,推断100例男性耻骨联合、100例男性胸骨和94例男性锁骨的年龄,计算准确率。结果骨盆性别判定准确率为98.4%,耻骨下角和坐骨大切迹是区分性别最好的两项指标。男性耻骨联合、胸骨、锁骨的年龄推断准确率在45%以上,其中锁骨双侧方程准确率最高为77%。结论利用骨骼CT三维重建图像判定性别和推断年龄具有可行性。使用大体标本建立的骨盆形态学性别判定方法可直接应用于骨骼CT三维重建图像。使用大体标本建立的男性耻骨联合、胸骨、锁骨形态学年龄推断指标、分级和评分标准以及方程需要修改和补充。     

Reproducibility of facial soft tissue thicknesses for craniofacial reconstruction using cone-beam CT images

The purpose of this study was to evaluate the reproducibility of the soft tissue (ST) thicknesses at 31 landmarks using the cone-beam computed tomography (CBCT) images obtained from 20 adult subjects. Four observers carried out ST thickness measurements using Skull Measure software, and the inter- and intra-observer error rates were evaluated. Only five of 31 landmarks showed significant differences in recorded ST thickness between the observers. When excluding inexperienced observers, only one landmark showed a significant difference between the observers. Regarding the intra-observer reproducibility, the ST thickness measurements at three landmarks showed low correlation coefficients. The results of this study indicate that CBCT images can be used to measure ST thickness with high reproducibility. However, some landmarks need to be redefined to reliably measure ST thickness on CBCT images.     

CT测量在眶内壁骨折损伤程度鉴定中的应用

目的 利用CT测量眶内壁骨折案件中伤者眶容积扩大率及眶内壁骨质缺损面积,探讨两种CT测量值用于评估眶内壁骨折范围的可行性.方法 选取20例无眼眶骨折案件作为对照组,使用CT测量双侧眶容积,并比较两例是否存在差异.选取本院2018-2020年间受理的眶内壁骨折案件39例作为实验组,并根据鉴定意见分为轻伤组与轻微伤组.分别...     

Accuracy of 3D Scanners in Tooth Mark Analysis

The objective of this study was to compare the accuracy of contact and laser 3D scanners in tooth mark analysis. Ten dental casts were scanned with both 3D scanners. Seven linear measurements were made from the 3D images of dental casts and biting edges generated with DentalPrint© software (University of Granada, Granada, Spain). The uncertainty value for contact 3D scanning was 0.833 for the upper dental cast and 0.660 mm for the lower cast; similar uncertainty values were found for 3D-laser scanning. Slightly higher uncertainty values were obtained for the 3D biting edges generated. The uncertainty values for single measurements ranged from 0.1 to 0.3 mm with the exception of the intercanine distance, in which higher values were obtained. Knowledge of the error rate in the 3D scanning of dental casts and biting edges is especially relevant to be applied in practical forensic cases.     

不同年龄组颅脑损伤CT扫描分析

本文对520例不同年龄组的颅脑损伤CT片进行了观察分析，表明青少年损伤原因以高坠多见，损伤类型以颅骨凹陷骨折及硬膜外血肿多见，老年组损伤原因以头部击伤多见，损伤类型以颅骨骨折、硬膜下血肿、脑多发性挫裂伤及脑多发性血肿多见，成年组介于两者之间。     

A Preliminary Study of the Reliability of Anatomical Facial Landmarks Used in Facial Comparison

Anatomical landmarks are considered the most objective indicators for use in forensic facial comparisons. Therefore, accurately identifying and locating these landmarks is the beginning of reliable facial comparison. This study evaluated the accuracy with which facial landmarks are located and examined their reliability according to type of landmark, head posture, and image quality. Nine operators located a series of landmarks on prepared facial images used to produce comparison images. Then, the average distances between the reciprocal landmarks (ADRL) on the reference and the comparison images were measured as indicators of landmark reliability. We found that a set of landmarks had higher or lower reliability as a function of the head angle and image quality. More reliable landmarks were associated with certain head postures and degrees of image quality. These should be used for facial comparison analysis depending on various head and image conditions.     

Histologic findings of the sinus node and the perinodal area in street heroin addicts, victims of sudden unexpected death

Sudden unexpected death is frequent in street heroin addicts. We conducted a histologic study of the sinus node (SN) to offer some evidence about the possible arrhythmogenic cause of death. Postmortem coronary angiography and microscopic examination of the SN and the perinodal area were performed in 50 heroin addicts (group 1) and in 50 nonaddicts (group 2), all men (16-40 years old). In heroin addicts, fatty and/or fibrous tissue replaced SN tissue in 21 cases (42%). Perinodal infiltration was found in 15 cases (30%). Fibromuscular dysplasia in branches of the sinus node artery (SNA) was found in eight cases (16%). Inflammation with focal and/or diffuse concentration of round cells was detected in the SN in 22 cases (44%). Old mural thrombi were also found in 13 cases (26%). The histologic changes in the SN and perinodal area offer an explanation about the possible mechanism of arrhythmia and sudden death in this population.     

Evaluation of Mastoid Process as Sex Indicator in Modern White Americans using Geometric Morphometrics

Conventional methods for evaluating the mastoid as a sex indicator cannot determine whether mastoid shape is an independent and reliable sex indicator. Here, shape differences between the mastoids of 100 male and 100 female modern white Americans were statistically analyzed and visualized using the geometric morphometric method. Discriminant analysis was performed on mastoid size and shape. The relation between size and shape was analyzed to examine the effect of size on shape. In the results, mastoid size and shape were statistically significant sex indicators, while size factor explained 87.3% of the total variance of the shape variables. Nevertheless, females had relatively broader and shorter mastoid shape than males regardless of size, reflecting 12.7% of the total variance of the shape variables. In conclusion, mastoid size and shape were statistically significant sex indicators, while size may matter more in the mastoid than in other cranial parts in terms of sexual dimorphism.     

Age Estimation in Living Adults using 3D Volume Rendered CT Images of the Sternal Plastron and Lower Chest

Age estimation is commonly of interest in a judicial context. In adults, it is less documented than in children. The aim of this study was to evaluate age estimation in adults using CT images of the sternal plastron with volume rendering technique (VRT). The evaluation criteria are derived from known methods used for age estimation and are applicable in living or dead subjects. The VRT images of 456 patients were analyzed. Two radiologists performed age estimation independently from an anterior view of the plastron. Interobserver agreement and correlation coefficients between each reader's classification and real age were calculated. The interobserver agreement was 0.86, and the correlation coefficients between readers classifications and real age classes were 0.60 and 0.65. Spearman correlation coefficients were, respectively, 0.89, 0.67, and 0.71. Analysis of the plastron using VRT allows age estimation in vivo quickly and with results similar than methods such as Iscan, Suchey–Brooks, and radiographs used to estimate the age of death.     

Sensitive determination of barbiturates in biological matrix by capillary electrophoresis using online large-volume sample stacking

In China, some forensic cases are caused by barbiturates. Thus, the determination of trace level barbiturates in body fluid is important for the poisoning investigation. In this study, an online large-volume sample stacking (LVSS) with polarity switching in capillary electrophoresis (CE) was applied for the sensitive determination of barbiturates. This technique involves injecting a large volume of sample into a capillary and removing the sample matrix plug out of the capillary by reversing the polarity. Quantitation limit obtained was 0.048, 0.057, 0.039, and 0.015 μg/mL for secobarbital, amobarbital, barbital, and phenobarbital (signal-to-noise ratio = 9). By using LVSS, the stacking was simply achieved at 171.7-, 169.7-, 202.7-, and 169.1-fold for the above four barbiturates. The relative standard deviation values of intraday and interday were <2.11% and 4.69%, respectively. Recoveries were ranged from 83.7 to 105.2%. Finally, the trace analysis method was applied to the analysis of real forensic specimens and has achieved satisfactory results.     

Rapid and simple GC-MS method for determination of psychotropic phenylalkylamine derivatives in nails using micro-pulverized extraction

A rapid and simple gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the simultaneous detection and quantification of five psychotropic phenylalkylamines (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, and norketamine) in toenails. After external decontamination, nail clippings were mechanically pulverized with a bead mill and then incubated in methanol under ultrasonication at 50°C for 1 h. The resulting solutions were evaporated to dryness, derivatized, and analyzed by GC-MS. The intra- and inter-day precisions were within 10.7% and 13.9%, respectively. The intra- and inter-day accuracies were -4.2% to 5.0% and -2.4% to 8.4%, respectively. Limits of detection and quantification for each analyte were lower than 0.024 and 0.08 ng/mg, respectively. The recoveries were in the range of 80.6-87.5%. The results indicated that the proposed method is a simple, rapid, accurate, and precise for quantification of five phenylalkylamines in nails. The method was successfully applied to the simultaneous detection and quantification of phenylalkylamines in nail samples of possible drug abusers.     

A quantitative method for simultaneous determination of 5-methoxy-N,N-diisopropyltryptamine and its metabolites in urine using liquid chromatography-electrospray ionization-tandem mass spectrometry

5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT) is a designer hallucinogen derived from tryptamine and is reportedly abused and involved in criminal activities. For the detection of 5-MeO-DIPT use, a liquid chromatography-tandem mass spectrometric method for 5-MeO-DIPT and its metabolites, 5-hydroxy-N,N-diisopropyltryptamine (5-OH-DIPT) and 5-methoxy-N,N-isopropyltryptamine (5-MeO-IPT) was developed and validated in rat urine. The urine samples were pretreated by protein precipitation with acetonitrile and introduced into a BDS HYPERSIL C(18) column (50 × 2.0 mm, 5 μm) for chromatographic separation. Mobile phases consisted of methanol, water, and 1% formic acid, and gradient elution was used at a flow rate of 0.2 mL/min. For the MS detection, multiple-reaction monitoring analysis was adopted. The linear range was 0.01-10 μg/mL, and the lower limit of quantification was 10 ng/mL for all analytes. The intra- and interday accuracies and precisions met the criteria (<15%). The developed method was successfully applied to the drug-treated rat urine.