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。     

正畸治疗前后腭皱的法医同一认定研究

目的利用腭皱模型分析法评价腭皱形态的个体独特性及正畸治疗前后腭皱形态的稳定性,探索腭皱形态在法医齿科学个体识别应用中的可靠性。方法分别收集70例正畸治疗前、后的上颌模型。通过模型测量分析对腭皱形态及个体识别进行检测,包括数量、方向、形状及长度的变化和近、远中侧端点分别在近远中向及前后方向上的位移。同时对正畸治疗前、后及正畸治疗后与其复制后腭皱模型进行配对检测,计算其平均正确配对率(%)。结果 (1)正畸治疗后腭皱数量、方向、形状及长度均有变化,表现为长度变化(28.6%);分裂(4.3%);联合(2.9%);方向变化(1.4%);形状变化(1.4%)。并且治疗后腭皱远中端点的前后向位移变化占45.7%,近远中向位移占40%;而腭皱近中端在在前后向和在近远中向上位移变化分别为32.9%和17.1%。(2)正畸治疗前组及正畸治疗后组不同个体均未发现相同的腭皱模式。(3)正畸治疗前、后模型的腭皱平均正确配对率为92.19%。而治疗后模型与复制后模型的腭皱平均正确配对率是99.05%。结论腭皱形态具有高度的个体特异性,尽管正畸治疗后腭皱的形态有一定变化,但仍可作为一种新的方法应用于法医齿科的同一认定。     

法医学同一认定中腭皱图像感兴趣区域边界标定

目的 研究一种基于最小二乘拟合的用于腭皱区域边界计算的方法.方法 根据牙齿的分布情况选择特征点,通过对选取的特征点进行最小二乘拟合,建立腭皱区域边界,根据上述边界构造掩模,去除掩膜外侧的部分,来滤除干扰.结果 对拟合曲线的定量结果进行评价,通过6个拟合过程得到样本的相关系数(r)以及实测均值与理想均值.在6次拟合过程中...     

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。     

根据颈椎CT片特征指标进行同一认定的研究

目的选择颈椎CT片上的特征指标,建立逐步回归方程,探讨其在法医学同一认定中的应用价值。方法收集130名被检查者颈椎CT片各1张,70名被检查者不同次颈椎CT影像片各2张。选择并测量颈椎CT片上的13项指标值,分别计算被检查者随机分组后相同测量指标的组间差值,以及同一人不同次测量指标间的差值,运用二分类logistic逐步回归分析,建立各项指标的一元回归方程和多项指标的多元回归方程,并对方程进行盲测检验。结果建立的13个一元方程中同一认定的准确率在69.0%~90.4%之间;建立的4个多元回归方程的准确率在90.4%~96.7%之间,盲测准确率为100%。结论本文在CT片上选择的13项特征指标可以用于同一认定,使用时应尽可能选用多元指标以得到更准确的结果。     

根据骨盆CT片特征指标进行同一认定的研究

目的选择骨盆CT片上的特征指标,建立逐步回归方程,探讨其在法医学同一认定中的应用价值。方法收集160名不同被检查者骨盆CT影像片各1张,70名被检查者不同次骨盆CT影像片各2张。选择并测量骨盆CT片上的14项指标值,分别计算不同人随机分组相同测量指标的组间的差值,以及相同人不同次测量指标间的差值,运用二分类logistic逐步回归分析,建立各项指标的一元回归方程和多项指标的多元回归方程,并对方程进行盲测检验。结果建立的14个一元方程中同一认定的正确率在61.1%(骶骨耳状面后缘宽)~80.5%(第一骶椎平面左右髂骨前端间距)之间;建立的6个多元回归方程的正确率在80.5%~93.8%之间。盲测准确率为100%。结论本文在CT片上选择的14项特征指标可以用于同一认定,在使用时应尽可能选用多元指标以得到更准确的结果。     

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。     

头颅CT片同一认定研究

目的探寻头颅CT片同一认定的方法。方法分别计算同一被检查者不同次头颅CT片指标差值和不同被检查者头颅CT片指标差值，再应用二分类logistic回归分析相同被检查者和不同被检查者指标差值，建立头颅CT片同一认定回归方程。结果建立头颅CT片同一认定方程46个。结论通过头颅CT片测量可以进行有效同一认定。     

头颅CT片同一认定研究

目的探寻头颅CT片同一认定的方法。方法分别计算同一被检查者不同次头颅CT片指标差值和不同被检查者头颅CT片指标差值,再应用二分类logistic回归分析相同被检查者和不同被检查者指标差值,建立头颅CT片同一认定回归方程。结果建立头颅CT片同一认定方程46个。结论通过头颅CT片测量可以进行有效同一认定。     

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。     

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 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.     

Frequencies of morphological characteristics in two contemporary forensic collections: implications for identification

Positive identification relies on comparison of antemortem and postmortem data. Some identifications are based on morphological features such as fracture, pathological condition, and surgical hardware, despite little literature indicating the frequencies of such traits. This study examines whether such features are sufficiently rare as to be deemed individualizing. Data were collected on two modern North American skeletal collections (N=482 individuals). Presence/absence of features was scored by skeletal element and side. Results indicate that frequencies vary by geographic region (higher frequency of fractures and pathological conditions in New Mexico while individuals in Tennessee were more likely to have surgical interventions), many features such as fractures are remarkably common and that even suites of traits may not be individualizing. Caution is warranted when using written data rather than radiographic comparisons as the primary source of identification. The implications of these findings to missing person databases are also discussed.     

根据数字全颌曲面断层片进行个体识别研究

目的建立中国恒乳牙交替完全人群数字全颌曲面断层片的同一认定方法。方法对120例中国恒乳牙交替完全人群的数字全颌曲面断层片进行测量和分析,对每颗牙齿的影像分别选取5个长度性指标和5个角度性指标,运用efilm workstation 2.1软件进行测量,SPSS 13.0软件对数据进行处理和统计。结果各观测指标的测量值在分段赋值区段里的分布概率有所不同,最大可达99.166 7%。两张同源数字全颌曲面断层片之间的分段赋值匹配概率最高为98.947 368 42%,最低为89.473 684 21%。结论所建立分段赋值匹配概率同一认定法经盲测验证,效果较好,该方法可为个体识别提供参考。     

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。     

The use of orthopedic surgical devices for forensic identification

Surgically implanted devices have become increasingly common in modern skeletal material. Therefore, having the knowledge of the variety of implanted orthopedic devices, their manufacturer, and where to find and how to use identifying numbers in such implants can assist in the identification process when traditional methods are not applicable. Orthopedic device manufacturers are required by the Safe Medical Devices Act of 1990 and the FDA Modernization Act of 1997 to track permanently implanted devices. Manufacturer information on orthopedic devices associates the orthopedic surgeon who implanted the device with the patient. By providing a current list of the most common orthopedic device manufacturers in the U.S.A. and the associated contact information, investigators will have updated tools for the individuation process. Despite numerous complicating factors regarding how device data are tracked, the information presented here can assist forensic professionals with obtaining presumptive and/or positive identifications.     

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。