应用数字图像识别系统研究正畸治疗前后腭皱形态变化

目的利用腭皱数字图像识别系统对正畸治疗前后腭皱形态匹配正确率的分析研究,为法医学中同一认定提供理论依据。方法利用正畸患者治疗前后腭皱形态数字图像,通过腭皱数字图像识别系统对图像的特征进行提取并收录到腭皱数字库,运用Matlab软件完成对腭皱形态数字图像的信息匹配处理。结果正畸治疗前后,个体性检测匹配正确率各自都达到100%。正畸治疗前后腭皱形态匹配正确率为95.67%,配对检验结果 P0.05,具有统计学意义。结论腭皱形态具有高度的个体特异性,正畸治疗后腭皱形态会发生多种变化,但对同一认定的影响不大。腭皱形态识别为法医学同一认定提供一种新的方法和途径。     

利用腭皱特征进行同一认定的指标体系构建

目的根据腭皱的形态图特征,进行口腔腭皱在法医学同一认定的指标体系构建。方法收集100例成年人腭皱模型,依据腭皱的形状、数量、位置分布等特征对腭皱形态图进行全面系统的编码。编码顺序采用英文字母按照先右侧再左侧,先前部再后部的顺序编码,并且右、左侧编码以破折号连接。最后依据编码,统计分析腭皱形态分布特征。结果 100例腭皱形态图中,个体间未见完全一致者,每个个体不论男性与女性均表现有独特的腭皱形态图;且同一个体左右侧单条腭皱的形态及分布亦不同。波浪形腭皱所占比例最大（23.03%）,三分叉形出现比例最小（0.74%）,不同性别的波浪形及曲线形腭皱所占比例均较大,女性波浪形（22.7%）及曲线形（18.28%）;男性波浪形（24.11%）及曲线形（21.43%）。结论口腔腭皱法医学同一认定的指标体系构建,将为法医学的同一认定提供一种新的方法。     

衰老相关生物分子标志物在法医年龄推断中的研究进展

未知个体的年龄推断能够在案件侦破、灾害遇难者鉴别及失踪人员调查等法医工作中提供重要线索。随着衰老相关生物分子标志物研究的开展，多种生物标志物被证明与年龄密切相关，如DNA甲基化、端粒长度、非编码RNA等，基于生物分子标志物构建年龄推断模型成为法医遗传学的研究热点。本文就目前常见随龄变化的生物分子标志物在法医年龄推断领域中的应用现状进行综述。     

长度多态与序列多态STR模型法庭科学参数比较

基于毛细管电泳平台进行STR基因座分型是当前个体识别的金标准。二代测序技术支持STR序列多态分型,并有可能在法庭科学领域被广泛应用。相比长度多态性,STR测序可提供更大的信息量,但相关法庭科学参数的定量计算十分必要。本文建立了简单的STR基因座模型,分别计算了长度多态和序列多态STR模型基因座的法医遗传学参数,结果表明:对于单个STR基因座,其序列多态模型的个体识别力和非父排除率相比长度多态模型更高,说明序列多态STR遗传标记识别无关个体及排除非父的能力更强。在联用15个非连锁遗传模拟基因座进行法医DNA分析时,长度多态模型和序列多态模型的累积匹配概率分别在10-18和10-26量级;而如果要达到长度多态模型15个基因座的累积匹配概率(10-18),仅需使用10个非连锁模拟序列多态STR基因座。希冀此模型比较能为二代测序STR数据的法庭科学应用提供参考。     

大鼠缺O_2高CO_2性脑损伤神经细胞凋亡的研究

目的观察缺O2高CO2性脑损伤的形态变化。方法缺O2高CO2大鼠模型,应用透射电镜,原位末端标记法(TUNEL)、流式细胞仪技术,观察脑组织的形态变化。结果脑神经细胞发生变性、坏死及细胞凋亡。结论缺O2高CO2性脑损伤的形态变化,可为法医病理诊断提供一项新的辅助诊断依据。     

冠心病猝死冠状动脉粥样硬化斑块病理形态学观察

目的观察冠心病猝死(SCD)和对照组心冠状动脉(CA)粥样硬化斑块的差异,探讨其在SCD中的意义。方法从本教研室2001年~2003年尸检档案中挑选64例有严重CA粥样硬化病变的病例及心脏标本,分SCD组(36例)和对照组(28例冠心病非猝死者)。除常规检查心脏外,重点检查CA左主干(LM)、左前降支(LAD)、左旋支(LC)和右主支(RM)的开口、类型、走向及粥样硬化斑块情况。每支CA分近、中、远3段,检测每个斑块距开口的距离、狭窄程度、长度、数目和形状(分偏心、环形、偏心+环形三种)。用SPSS11.5统计软件进行统计分析。结果SCD组中CA粥样硬化病变4级21例,3级15例;对照组4级12例,3级16例。两组斑块病变的严重程度无显著性差异(P>0.05)。SCD组粥样斑块长(x-2.0365 cm)、以CA近段较多、与CA开口或分支处的距离近(x-0.7457 cm);对照组斑块短(x-1.4283 cm)、以中段多见,与CA开口或分叉处的距离远(x-2.1942 cm);两组斑块的长度和距开口的距离均有非常显著性差异(P<0.01)。两组间斑块的形状在LAD和RM有显著性差异(P<0.05),而LM和LC则无(P>0.05)。结论SCD与冠心病非猝死者的CA粥样硬化斑块在部位、长度、形状和距CA开口的距离存在差异,而狭窄程度无差异。这对SCD的病理诊断和法医学鉴定具有十分重要的意义。     

33例外伤性鼓膜穿孔的法医临床学分析

鼓膜穿孔是耳科常见病症,在法医临床学检验鉴定中,鼓膜穿孔需区别外伤性、非外伤性鼓膜穿孔,或是否属造作伤后方能做出正确鉴定结论。现就本室检验鉴定的33例鼓膜穿孔总结分析如下。1案例资料一般资料男性23例,女性10例,年龄在25~67岁,右耳10例,左耳23例。致伤原因掌拳伤25例,鞋底伤1例,扫帚伤1例,烫伤1例,中耳炎2例,造作伤3例,其中8例耳部有明显外伤。检查时间伤后1周内检查30例,1周以上检查3例。穿孔部位及形状特征采用电耳镜结合鼓膜照相的检查方法,发现本组中25例穿孔位于紧张部前下方,5例位于紧张部后下方,1例伤及松弛部(烫伤),1例位于…     

36例脑血管畸形猝死案例及法医病理学分析

目的探讨脑血管畸形猝死的法医病理学特点和检查方法。方法对1997年至2006年10月四川华西鉴定中心所做36例脑血管畸形猝死病例进行分析。结果脑血管畸形猝死以10~49岁男性为主,有25例(69.44%)。18例(50%)发病前有明显诱因。18例(50%)在发病后1h内迅速死亡。脑血管畸形猝死的病理类型以脑动静脉畸形最为常见,有33例(91.67%)。24例(66.67%)发生于脑底部、桥脑和小脑。破裂出血是脑血管畸形猝死的直接死因,出血类型以蛛网膜下腔出血最为常见,有22例(61.11%)。脑血管畸形部位和形态复杂多变,常规检查方法不能满足鉴定的需要。结论脑血管畸形猝死的鉴定百分之百准确比较困难,熟悉其法医病理学特点,掌握多种检查方法,才能做出客观、全面、准确的鉴定结论。     

胸骨性别判定的研究进展

人类胸骨的形态特征与性别具有密切关系,各项研究普遍认为,胸骨具有显著性别差异,其指标有:胸骨总长、胸骨体长、柄宽、柄厚、体宽、体厚、胸骨面积。但指标胸骨柄长、胸骨指数的性别差异仍然存在争议。合理联用性别差异显著的相关指标,建立性别判别方程式,确定相应的临界判别值,判定性别即可获得较高的正确率。现有数据显示,国内外研究胸骨判定性别结果的精度可高达90%以上。目前国内的研究方法主要为通过手工测量长度指标获取测量值,计算有关指数,此类方法对骨骼的处理费时费力且人为因素影响较大。医学影像技术的进步,有望简化处理该过程,使得研究结果更为科学精确,特别是多层螺旋CT在法医人类学检查、测量及同一认定中具有实用价值。借鉴国外一些利用X线摄影、CT扫描技术进行有关研究的方法,采用多层面重组结合三维重建图像的测量方法有望获得更为准确的测量数据,为胸骨的性别判定提供1种快捷、准确的新途径。本文对国内外胸骨性别差异的相关研究成果进行了综述,尤其关注了法医学个体识别方面的数据,这些资料为研究胸骨三维重建影像的形态特征奠定了基础,将有力促进胸骨个体识别方法的突破性发展。     

造作伤法医临床学检验1例

正1案例资料1.1简要案情许某,男,29岁,2014年12月23日与他人发生争执,互殴后致伤。临床查体见头颅无畸形,头部可见多处开放性伤口。头颅CT未见明显异常。1.2法医学检验2015年1月14日法医门诊查体见:顶部头皮条状愈合期瘢痕2处,平行排列,长度分别为2.9cm及2.5cm,见1处未缝合的条状浅表瘢痕,长2.0厘米(图1);右颞顶部头皮条状愈合期瘢痕4处,     

Stability of Palatal Rugae as a Forensic Marker in Orthodontically Treated Cases

The palatal rugae have been used as a reference landmark and identification marker by orthodontists and forensic analysts. However, the reliability of palatal rugae as a forensic marker remains questionable once an individual is subjected to orthodontic treatment. This study aimed at evaluating the changes in the rugae pattern after nonextraction, extraction, and maxillary expansion orthodontic treatment. The lengths and shapes of palatal rugae were evaluated on the pretreatment and post‐treatment dental casts of 168 subjects using the Thomas and Kotze classification. Extraction treatment significantly reduced the second and third rugae lengths (p < 0.05), whereas the third rugae length was significantly increased after palatal expansion (p < 0.05). The shape of rugae remained consistent in all the study groups which may be used as a reliable forensic marker in subjects undergoing orthodontic treatment. However, the use of the lengths of palatal rugae in forensic odontology must be made with caution.     

腭皱法医学同一认定数字化系统的建立

目的建立腭皱法医学同一认定数字化系统并对其进行效果评价。方法在标准条件下获取腭皱的数字图像,对腭皱信息都进行采集、降噪、增强、分割、特征提取、边缘检测、信息匹配等处理,运用Matlab软件研制腭皱法医学同一认定系统,并进行效果评价。结果本研究成功建立腭皱法医学同一认定数字化系统,从匹配结果来看,正确率达到100%。结论腭皱法医学同一认定数字化系统的建立,为同一认定提供一种新的方法和途径。     

Individuality of human palatal rugae

Investigators have implied that palatal rugae are unique to each individual. However, these researchers have disagreed as to whether or not legal identification could be based solely on palatal rugae. Previous studies used poor duplicating materials and may not have considered the effects of growth, extractions, palatal expansion, or some combination of these. The inadvertent use of other features of the cast, such as teeth, edentulous ridge morphology, muscle attachments, vestibular depth, or some combination of these, to aid in the identification, may have influenced their results. The purpose of this investigation was to determine if palatal rugae can be relied upon for identification. Twenty-five orthodontic cases were selected with pre- and post-treatment casts; orthodontic treatment had taken eighteen to sixty months. One hundred casts were randomly selected as variables. All casts were trimmed so that all areas except for the rugae area of the hard palate were removed. The twenty-five post-orthodontic casts were dispersed within 100 randomly selected casts. Nine investigators were given the twenty-five pre-orthodontic casts and asked to compare them to the other one hundred and twenty-five casts for possible matches. Data were collected as to percentage of correct matches and time required for comparison. Each set of pre- and post-orthodontic casts was properly identified (100%) by 8 investigators, and the remaining investigator correctly matched 22 out of 25 casts (88%). These conclusions were drawn.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Heritability of Palatal Rugae Morphology Among Siblings*†

Although there is clinical applicability of the palatal rugae as an identification tool in forensic odontology, controversy exists whether the palatal rugae patterns are stable or variable. The greater the genetic component, the higher the probability that palatal rugae patterns are stable. The aim of this study was to compare the palatal rugae morphology between full siblings and the proportion of variability due to genetic component. This cross-sectional study was conducted on digital models of 162 siblings aged 15–30 years old. The palatal rugae patterns were assessed with Thomas and Kotze (1983) classification using Geomagic Studio software (3D Systems, Rock Hill, SC). The palatal rugae morphology between siblings showed significantly similar characteristics for total number of left rugae (p = 0.001), left primary rugae (p = 0.017), secondary rugae for right (p = 0.024) and left sides (p = 0.001), right straight rugae (p = 0.010), and right convergent rugae (p = 0.005) accounting for at least 6.25%-12.8% of the variability due to heredity. Despite the similarities found, the palatal rugae patterns showed significant differences between siblings of at least 46.9% (p = 0.001). Zero heritability was found in 9 of the 14 rugae patterns. Meanwhile, total number of rugae, primary, backward, and convergent rugae showed moderate heritability (h² > 0.3) and total number of secondary rugae showed high heritability (h² > 0.6). In conclusion, despite the individuality characteristics, an appreciable hereditary component is observed with significant similarities found between sibling pairs and the palatal rugae patterns were both environmentally and genetically influenced.     

Palatal rugae pattern in a Portuguese population: a preliminary analysis

Palatal rugae have been related with specific racial groups and are said to be useful in sex discrimination. This work aimed to characterize the palatal rugae patterns in a Portuguese population. Fifty plaster casts were examined for first and third rugae shape evaluation; shape, frequency, and association with sex were studied. In females, the most prevalent first rugae were the straight type on the right and the curve type on the left; in males, the straight type was the most prevalent on both sides. The most frequent third rugae type was sinuous on both sides, in both sexes. No significant sexual dimorphism in rugae shape was found (p > 0.05). When comparing these results with those from other investigations, it was clear that a particular rugae pattern could be established for different ethnic groups. However, the small sample size justifies further work in larger samples to validate these findings.     

Indication and limitations of using palatal rugae for personal identification in edentulous cases

To explore the availability and the limitations of using the palatal rugae pattern in forensic practice for personal identification in edentulous cases, we set up an experiment, which involved 48 patients who had both old and new complete dentures and we observed their rugae. First, we made 48 pairs of maxillary casts from their old and new dentures and a further 50 maxillary casts from complete dentures at random, to use as variables. All the initial impressions taken from the mucosal surfaces of complete dentures were made from alginate impression materials, and the maxillary casts were made from hard dental plaster. Secondly, all 146 casts were trimmed so that all the areas except for the rugae area were removed. Subsequently, 50 examiners were given the 48 casts from the old dentures and were then asked to compare them with the other 98 casts for possible matches. The case numbers, which matched correctly, were recorded. The median percentage of correct matches among the 50 examiners was 94%, despite variations in their experience with forensic identification, and this accuracy does not differ significantly from that in dentate cases, as described in previous publications. The median percentage of correct matches among the 48 cases was 90%. Analyzing the incidence of obtaining a correct match in each case revealed that there were three major misleading shapes that could give rise to a low rate of correct matches; (1) severely low and poorly demarcated eminences of rugae, (2) change of palatal height, and (3) non-complex rugae pattern. These features are mainly due to the shape of the edentulous palate itself and rarely due to the dentures, and could lead to difficulties in finding unique points for use in matching rugae patterns. The results suggest that an appropriate selection of cases, taking into consideration the above misleading shapes, may establish an increased rate of accuracy for identification with this method, thereby bringing the percentage of correct matches closer to 100% in edentulous cases, which is also the percentage of correct matches previously reported in dentate cases.     

Morphological pattern of palatal rugae in children of Davangere

The aim of this study was to identify and compare the rugae pattern between males and females of two different communities in the city of Davangere, Karnataka, India, which may be an additional method of identification in cases of crimes or communal riots. Elastomeric impressions of the maxillary arch of 100 selected children were made; casts were poured in Type IV stone. The method of identification of rugae pattern followed was that of Lysell and Thomas and Kotze, which includes the number, shape, direction, and unification of rugae. The study revealed no significant difference in the total number or length of rugae between the two communities and sexes. However, with regard to shape and unification, females showed a significantly higher diverging rugae type while males had a significant number of circular and converging type of rugae. Also, discrimination function analysis allowed a moderate differentiation of the population. Hence, the rugae pattern can be an additional method of differentiation in conjunction with the other methods such as visual, fingerprints, and dental characteristics in forensic sciences.     

Palatal rugae as an individualising marker: reliability for forensic odontology and personal identification

Personal identification is based on the comparison between ante mortem and post mortem data which can be considered unique for each individual: palatal rugae represent a useful element for such a comparison, thanks to their apparent low variability with time and unique patterns. Literature however is scarce.This pilot study aims at assessing the reliability of palatal rugae in time and at developing an identification method based on their comparison. Two casts from the upper dental arch of 39 subjects were obtained in different periods of time; at their first cast, 85.2% of patients were less than 16 years old. The second cast was performed after a period of time which varied between 4 and 65 months later than the first cast. The first cast can be taken to simulate ante mortem information, the second post mortem information. Every cast was then digitised with a scanner. In the digital images the palatal rugae were highlighted by using Adobe® Photoshop® 7.0 software; each image was coded and a comparison between “simulated” ante mortem and post mortem data was performed. In all cases ante mortem and post mortem data from the same individual were correctly matched.The study seems to indicate that this technique is highly reliable and user friendly, even on subadults, where growth processes seem not to affect the specific morphology of palatal rugae.