数字全口牙位曲面体层片的法医学同一认定指标

目的采用颌面全口牙位曲面体层片,针对牙齿无病变者筛选简洁实用的法医学同一认定识别指标并进行编码、统计分析及评估。方法随机选取170例牙齿无病变者的颌面数字全口牙位曲面体层片进行观测．根据牙齿的生理变异特征和牙齿的排列特征分别筛选全口牙型和牙列型识别指标。按设计的编码标准对全口牙型、牙列型逐一编码,统计分析编码的多样性,以评估两类识别指标的应用价值。结果170例中共有74种全口牙型编码,多样性为43．53％：170例中共有129种牙列型编码,多样性为75．88％;170例同时进行全口牙型和牙列型编码．则共有150种全口牙型／牙列型编码,多样性为88．24％。结论全口牙型编码多样性较低,单独使用尚不能满足法医学同一认定的要求。牙列型编码的多样性比较高,具有一定的法医学同一认定价值。如果同时进行全口牙型和牙列型编码,多样性明显提高,有较高的法医学同一认定价值。     

颌面数字X线片的法医学同一认定

目的探讨颌面数字X线片(DigitalRadiology,DR)的全口牙型32位编码和测量6项骨性指标的变化特征,评估其在法医学同一认定的价值。方法随机选取颌面DR全景片300例,按设计的编码标准和原则对其全口牙型逐一编码,分析编码的多样性;随机选取颌面DR侧位片100例,由口腔放射科医生和培训过的法医研究生各一人对6项骨性指标(N-S,N-Me,Cd-Gn,Cd-Go,NP-SN,MP-SN)进行准确测量,计算指标的变异系数(CV),并对两人测量结果的一致性进行相关分析。结果(1)300例个人全口牙型编码,总体多样性为75%;牙齿有病变或治疗组的多样性为99.53%;(2)颌面DR侧位片中6项指标变异系数较大;(3)两次测量结果的相关系数均接近1,表明所选指标的测量结果稳定,有高度一致性。结论颌面DR全景片全口牙型32位编码和颌面DR侧位片中6项骨性指标可用于同一认定。     

X线头影侧位片同一认定指标的建立

目的探究口腔颌面X线头影侧位片的形态学分型,对识别指标进行数字编码,构建法医学同一认定体系。方法选取200例成年人口腔颌面的X线头影侧位片,通过SNA角、SNB角的相互关系及后面高与前面高比值,对颌面骨骼形态进行矢状向垂直向的综合分型,同时筛选出反映颌面特征的8个测量指标进行数字编码。结果依据矢状向、垂直向及8个测量指标构建的编码系统,其多样性较大,为99.5%。MP-FH和Y轴角的变异系数较大,同一认定价值较高。S-Ar-Go、Ar-Go-Me、MP-FH、1—-MP角、Y轴角、1—-SN角、1—-1—角各级别构成比间性别差异有统计学意义。结论利用头颅侧位片矢状向及垂直向分型并结合所选取的8项定量识别指标进行识别编码的方法,为法医同一认定提供了新思路。     

中国汉族成人颅骨CT片同一认定方法的研究

目的建立对中国汉族成人颅骨CT片进行同一认定的方法。方法按照纳入标准收集100例中国汉族成人颅骨CT片，对确定的识别指标进行观察和测量，对各指标的观测结果进行分类编码，然后按观测顺序编制特异的12位颅骨CT片识别编码。运用SPSS13．0统计学软件对所得数据进行各指标年龄和性别差异的统计学分析，利用个人识别能力公式计算单个指标和总体指标的个人识别能力。结果12项识别指标中有6个指标存在男女性别差异；12项指标累计个人识别能力可达到99．9997997％。结论本文确定中国汉族成人颅骨CT片12项观测指标，利用指标分类编码法可进行中国汉族成人颅骨CT片的同一认定。     

额窦数字X线影像分型与同一认定指标的筛选

目的 从法医学同一认定的视角探究柯氏位额窦计算机X线摄影(computer radiography,CR)的形态学分类,并结合识别指标的数字编码,构建X线影像同一认定体系.方法 收集 400例四川汉族成年人额窦标准柯氏位CR片.以两侧眼眶上缘均相切的直线与额窦的位置关系对额窦形态学特征进行分型研究,并对额窦识别指标进行数字编码.结果 提出额窦CR片影像学特征6类分型,筛选出额窦不对称性、最大额窦面积的侧别、同侧额窦面积与眼眶面积比、额窦上缘弓形弯曲数、额窦部分分隔位置、额窦中间隔位置等8项识别指标.结论 提出了先作分型鉴别,再用所选取的8项指标对额窦形态进行识别编码的柯氏位额窦CR片影像同一认定的新思路.     

医学影像资料法医学同一认定30例分析

目的探讨医学影像资料法医学同一认定的鉴定原则、思路及方法。方法总结华西法医学鉴定中心1992—2012年受理的30例医学影像资料同一认定案例,对影像资料数量、种类,鉴定利用的识别点及其类型、间隔进行回顾性统计分析。结果胸部X线片为最常见的鉴定资料类型。利用的识别点共有33处、6种类型,包括：自身惟一性特征、骨骼自身结构的变异或发育畸形、疾病或退行性变、创伤后病理变化、医疗后果和正常形态的多处一致。结论影像资料常规审查是案件受理前提之一,同一认定时结合资料类型、投照部位及案情特点选择相应识别点,自身惟一性识别点最佳,多种类型识别点联合使用,识别点多处表现一致得出肯定结论者可应用于鉴定实践。     

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。     

北京汉族群体9个STR位点的频率分布及法医学应用

提供北京汉族群体9个STR基因座的频率分布资料，了解其在法医学中的应用价值。应用PCR技术对9个STR基因座分3组进行复合扩增，经PAG电泳分离、银染，扫描仪扫描，计算机判读并保存结果，对北京地区汉族无关个体9个基因座的基因频率分布进行调查。结果显示，上述9个基因座的杂合度为0．6419～0．8092，多态性信息总量为0．9999，鉴别机率为0．9999，匹配机率为2．0×10-9和非父排除率为0．9985。STR3组9个基因座的综合检验可应用于法医学个体识别和亲子鉴定，并达到同一认定的标准。     

人发毛干角蛋白电泳谱型的分析

本文用SDS-梯度(5.0～17.0％)聚丙烯酰胺凝胶电泳对150例中国人头发角蛋白组分进行了分析。结果表明,在150例人头发中,有6种不同类型的角蛋白电泳谱型。此1～6型发生频率分别为24％、12％、42％、7.3％、8.0％;及6.7％。用N-(3-芘)马来酰胺标记头发角蛋白巯基,证实人头发不同类型的角蛋白电泳谱型主要区别在低硫蛋白部位。作者认为,人头发角蛋白电泳谱型的差异可为法医学鉴定中的毛发个人识别提供重要的依据。     

中国四川省汉族人群额窦CR片的同一认定

目的研究不同投照体位CR片上额窦用于同一认定的观测指标,以编制特异的识别编码.方法用两宽度比值与形态学描述相结合的方法观测额窦CR片,并采用描述性研究方法进行描述性研究和统计分析.结果以额窦不对称性AI、额窦与眼眶宽度之比RI、最大额窦宽度的侧别、额窦上缘弓形弯曲数目(左侧、右侧)、额窦部分隔数目(左侧、右侧)、额窦中间隔位置等8项指标,编制8位数字的额窦构型同一认定编码;额窦形态性别差异无统计学意义(P＞0.05).结论额窦形态高度个人特异,可以用于同一认定,但不能用作性别判断.     

The diversity of dental patterns in the orthopantomography and its significance in human identification

The primary aim of this study was to evaluate the utility of orthopantomography for human identification. Three hundred orthopantomograms were randomly selected from those stored at Dental Hospital of Yonsei University in Seoul. Dental patterns observed in the orthopantomograms were converted into eight codes and their diversity was calculated. The diversity of dental patterns in the orthopantomogram data was 99.92% for full dentition and the diversity of mandible (99.28%) was slightly higher value than that of maxilla (98.22%). In the case of molars and premolars in both jaws, the diversity values ranged from 92.13% to 96.04%. It was founded that orthopantomography is a valuable means of personal identification not only based on full dentition but also when only the posterior teeth are available. The present study indicates that orthopantomography is excellent means of forensic identification.     

The diversity of adult dental patterns in the United States and the implications for personal identification

Few would argue about the individuality of dental radiographs for forensic identification, but when an antemortem/postmortem comparison is based strictly on dental treatment notes and/or charts it becomes less certain. In the past, attempts to validate the high diversity of dental patterns created by combinations of missing, filled, and unrestored teeth have been based on unfounded statistical assumptions. The goal of this research is to present a statistically valid method of assessing dental pattern diversity for the identification of missing individuals. Empirical observation of large reference datasets was found to be the best technique for assessing dental diversity. This technique is nearly identical to the procedure used for mitochondrial DNA casework. For the research presented in this paper, two large datasets were used, one composed of U.S. military personnel and one composed of U.S. civilians. Dental patterns were found to be very diverse on a scale that is comparable to mtDNA. In addition, it was found that the diversity values remain very consistent regardless of the level of detail present in the treatment records. Overall, combinations of missing, filled, and unrestored teeth were found to be very individualistic and an excellent source for forensic identification.     

Establishing personal identification based on specific patterns of missing,filled, and unrestored teeth

The primary goal of this research is to examine the overall utility of nonradiographic dental records for the establishment of individual identifications. It was found that even without radiographic lines of comparison, charts and notes that accurately detail a missing individual's antemortem dental condition can be essential for establishing an identification. Based on an analysis of two large datasets, individual dental patterns were determined to be generally unique, or at least very uncommon. Through this type of empirical comparison, it is possible to establish a strong, quantifiable association with a missing individual. The results of this research indicate that a definitive number of points of concordance do not need to be established in dental identification cases. Each case must be assessed individually. The critical factor is to remove subjective judgment calls from dental comparisons. This research has proposed a new method of empirical comparison that allows forensic odontologists to derive objective frequency information regarding the occurrence of specific dental patterns in the general population. The method is similar to that used for mtDNA casework, and a computer program (OdontoSearch) has been developed to make the technique accessible. It was found that even a small number of common dental characteristics may produce a very rare dental pattern, a point that may be counterintuitive to many forensic odontologists.     

Associated postmortem dental findings as an aid to personal identification.

The use of the unique features of the human dentition to aid in personal identification is well accepted within the forensic field. Indeed, despite advances in DNA and other identification methodologies, comparative dental identifications still play a major role in identifying the victims of violence, disaster or other misfortune. The classic comparative dental identification employs the use of postmortem and antemortem dental records (principally written notes and radiographs) to determine similarities and exclude discrepancies. In many cases the tentative identification of the individual is unknown and therefore antemortem records cannot be located. In such a situation a dental profile of the individual is developed to aid the search for the individual's identity. With such a profile a forensic odontologist can identify and report indicators for age at time of death, race (within the four major ethnic groups) and sex. In addition to these parameters the forensic dentist may be able to give more insight into the individual. This paper outlines, for the non-expert, some of the additional personal information that can be derived from the teeth of the deceased, and which may assist in their ultimate identification.     

Ultraviolet illumination as an adjunctive aid in dental inspection

Tooth-colored resin fillings have become increasingly popular as restorative materials. Their presence in the dentition presents a challenge to the clinician and the forensic odontologist, as detection of the fillings can be difficult both visually and radiographically. As they necessarily form part of the unique dentition of an individual, recognition of the resins is important for forensic identification. Alternative light sources have been used with success in various fields of forensic science. In recent years small LED flashlights emitting at specific wavelengths in the ultraviolet light (UV) range have been developed. Their low cost, small size, and ready availability makes their use practical in both forensic dental inspection and clinical settings. UV inspection is of interest because enamel, dentin and dental materials all have differing fluorescent properties when illuminated by UV light. It was one goal of this research to quantitatively assess the fluorescence properties of modern restorative resins in order to predict their behavior during inspection using UV illumination. The second goal was to demonstrate practical use of UV in dental inspection with examples of how different materials fluoresce. Quantitative measurements were obtained for optical emission wavelength and intensity for 15 modern resins using a spectrophotometer. Results indicated that resin brands fluoresce at different wavelengths and with varying intensities. Practical use and comparison of the flashlights revealed that the most useful excitation wavelengths for resin detection were in the UVA range (365 and 380 nm). Porcelain restorations and composite resin fillings exhibited different responses to these two wavelengths and thus use of both is recommended for forensic dental inspection.     

Identification through X-ray fluorescence analysis of dental restorative resin materials: a comprehensive study of noncremated, cremated, and processed-cremated individuals

Tooth-colored restorative materials are increasingly being placed in the practice of modern dentistry, replacing traditional materials such as amalgam. Many restorative resins have distinct elemental compositions that allow identification of brand. Not only are resins classifiable by elemental content, but they also survive extreme conditions such as cremation. This is of significance to the forensic odontologist because resin uniqueness adds another level of certainty in victim identification, especially when traditional means are exhausted. In this three-part study, unique combinations of resins were placed in six human cadavers (total 70 restorations). Simulated ante-mortem dental records were created. In a blind experiment, a portable X-ray fluorescence (XRF) unit was used to locate and identify the resin brands placed in the dentition. The technique was successful in location and brand identification of 53 of the restorations, which was sufficient to enable positive victim identification among the study group. This part of the experiment demonstrated the utility of portable XRF in detection and analysis of restorative materials for victim identification in field or morgue settings. Identification of individuals after cremation is a more difficult task, as the dentition is altered by shrinkage and fragmentation, and may not be comparable with a dental chart. Identification of processed cremains is a much greater challenge, as comminution obliterates all structural relationships. Under both circumstances, it is the nonbiological artifacts that aid in identification. Restorative resin fillings can survive these conditions, and can still be named by brand utilizing elemental analysis. In a continuation of the study, the cadavers were cremated in a cremation retort under standard mortuary conditions. XRF was again used to analyze retrieved resins and to identify the individuals based on restorative materials known to exist from dental records. The cremains were then processed and the analysis was repeated to determine whether restorative resins could be found under this extreme condition. Under both circumstances, sufficient surviving resin material was found to distinguish positively each individual in the study group. This study showed the utility of XRF as an analytical tool for forensic odontology and also the significance of the role of restorative resins in victim identification, even after cremation.     

咬痕个体识别的比对方法

目的 建立一个牙模数据库,为通过牙齿、咬痕进行个人识别的研究及其在法医实践中的应用提供一种新方法。方法 经过对400例牙模进行分析、计算,将牙齿的形状、排列转换成数字型(X,Y)坐标,通过计算出每颗牙关键点与坐标原点的相对位置,在DOS系统下运用Borland C++5.0语言编写程序,快速地计算出牙齿和牙弓的特征。结果 能对牙模进行自动识别,达到排除与认定。其比对精度长度为1.3mm,角度3°;可取的最少牙点位数目为12～14较为合理,大致需要5～7个完整的牙痕。结论 该方法是研究咬痕与牙模比对的基础。     

Self-assessment of the forensic value of dental records.

One of the most important aspects of a person's dental record may well prove to be it's potential value should the forensic dental identification of their remains become necessary. The better the quality of the antemortem dental records, the easier and faster the identification of the remains will be. The forensic dentist must be able to select identifying features by decoding the deceased's antemortem dental records. A study was conducted on two groups of dentists who were asked to self-assess the forensic dental value of the dental records maintained in their own practices. The three most frequently recorded identifying dental features, other than caries and restorations, were the presence of diastemas, displaced or rotated teeth, and dental anomalies. Surveyed dentists imbedded identifying information into the removable prosthetic devices fabricated for their patients an average of only 64% of the time. Only 56% of the two groups combined felt that their dental chartings and written records would be extremely useful in dental identifications. It is concluded that the quality of antemortem dental records available for comparison to postmortem remains varies from inadequate to extremely useful. Practicing dentists can become valuable members of the dental identification process by developing and maintaining standards of record keeping which would be valuable in restoring their patients' identity.