活体跟骨数字X线片性别判定

目的应用数字X线摄影方法测量跟骨,评估5项测量指标在法医学性别判定中的价值。方法393例受试对象随机分组,实验组334例(男性148例,女性186例),验证组59例(男性26例,女性33例)。每一受试对象按照规定投照方法摄跟骨侧位DR片,分别测量5项跟骨长度指标。方差分析检验实验组各项指标性别间差异,Fisher判别分析及多元逐步判别分析建立性别判别函数。验证组样本数据回代,前瞻性评估判别效能。结果5项指标性别差异有统计学意义(P<0.001)。共建立了6组性别判别函数,性别判断正确率在78.4%～88.9%之间;回代检验,判断正确率在79.7%～86.4%之间。结论跟骨侧位数字X线片5项长度测量指标代入判别函数进行性别判定的方法可为法医学个人识别中的性别判定提供帮助。     

Root Morphology and Anatomical Patterns in Forensic Dental Identification: A Comparison of Computer‐Aided Identification with Traditional Forensic Dental Identification*

Abstract: An online forensic dental identification exercise was conducted involving 24 antemortem–postmortem (AM–PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM–PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT‐ID index = 0.923) and Spearman’s rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer‐aided dental identification allows for an objective comparison of AM–PM radiographs and can be a useful tool to support a forensic dental identification conclusion.     

Forensic age estimation on digital X-ray images: Medial epiphyses of the clavicle and first rib ossification in relation to chronological age

In recent years, there has been a renewed interest in forensic sciences about forensic age estimation in living subjects by means of radiological methods. This research was conducted on digital thorax X-rays to test the usefulness of some radiological changes in the clavicle and first rib. The sample consisted in a total of 123 subjects of Spanish origin (61 men and 62 women; age range: 5-75 years). From all subjects, a thorax posterior-anterior radiograph was obtained in digital format. Scoring for fusion of medial epiphyses of the clavicle was carried out by Schmeling's system and ossification of the costal cartilage of the first rib by Michelson's system. Degree of ossification and epiphyseal fusion were analyzed in relation with known age and sex of these subjects. The results give a minimum age of >20 years for full fusion of the medial epiphysis of the clavicle (Stages 4 and 5). Concerning the first rib, all subjects with the final Stage 3 of ossification were above 25 years of age. These results suggest that the first rib ossification might become an additional method to the ones so far recommended for forensic age estimation in subjects around 21. New research would be desirable to confirm this suggestion.     

应用下颌第三磨牙建立中国汉族18岁评估模型

目的探讨第三磨牙在活体年龄推断中的价值,评估第三磨牙能否作为18岁年龄节点的判断指标。方法应用Orhan改良的Demirjian分级标准对1 845例10~30岁个体的下颌第三磨牙分级并赋分,对性别差异进行t检验,建立第三磨牙推断年龄的三次回归模型。同时绘制各等级年龄累积分布图和ROC曲线评估第三磨牙与18岁间相关性,建立18岁Bayes判别分析方程。结果评估者内可信度为0.903。年龄与等级间呈中等相关。D、H等级存在两性差异(P0.05),余各等级均无性别差异。男性等级1~D,女性等级1~C均小于18岁;男女性等级H均大于18岁。ROC曲线下面积为0.797(P0.05)。结论第三磨牙等级与年龄间有较高的相关性,可用于18岁年龄节点的推断,但仍应结合其他指标相互印证协同鉴定。     

Suicidal hanging resulting in complete decapitation--forensic, radiological, and anthropological studies: a case report

The authors report a case of complete posthanging decapitation. The decapitated corpse lay against a pillar of a road bridge. The head had rolled 5 m from the trunk. The bridge was 7.2 m above the road level. The rope was 3.6 m long, its lower end was 3.6 m from the ground and its diameter was 10 mm. The noose used was a slip knot. Plain X-rays of the skull and cervical spine were obtained. The skull X-rays showed air in the meningeal spaces, in both lateral and third ventricles. The severance plane of the cervical spine was between the third and the fourth cervical vertebrae. No other cervical vertebral injuries were noted. At autopsy, the brain was macroscopically unremarkable except for air in the meningeal veins. The decapitation injuries of the head and the torso corresponded perfectly, without apparent loss of substance. The severance plane was confirmed. Dry bone study was carried out. Except for fractures of the extremities of the spinous processes of the second and third cervical vertebrae, no other bone injury of the spine was seen. The cervical vertebrae displayed numerous osteoarthritic lesions. The traditional hangman's fracture was not found. To the best of our knowledge, this is the first report of complete posthanging decapitation with a severance plane between the third and fourth cervical vertebrae.