Dental Cementum in Age Estimation: A Polarized Light and Stereomicroscopic Study

Abstract: Dental hard tissues are good candidates for age estimation as they are less destructive and procedures to determine age can be easily performed. Although cementum annulations and cementum thickness are important parameters in this regard, they are seldom used. This study was undertaken to review the methods, difficulties in execution of techniques, and accuracy of cementum thickness and annulations in estimating the age. Unstained and stained ground sections of tooth were used to measure cemental thickness and count cemental annulations based on which age was estimated and was compared with known age. Although there was positive relation between cemental thickness and annulations with age, only in 1–1.5% of cases, age could be predicted with accuracy.     

The influence of a shot distance on a profile of a wound canal in flat bones

Experimental shots were made from rifled weapons, from different distances, at isolated flat bones. There was established a significantly increased angle of the axial section of the cone-shaped defect due to the expanding sizes of the exit part of the wound canal (WC) and of the outlet opening as the shot distances increased. An expert's evaluation is offered to assess a shot distance involving the WC profile and by calculating an angle of the axial section of the cone-shaped defect on the basis of the inlet and outlet sizes and of the flat-bone thickness.     

Bermuda Triangle: the supply of services (implied terms) act 2003 and the competing theories of exemption clauses

Patton and Cook v Bank of Bermuda is a judgment that undermines the legal certainty which should have been brought about by the implementation of the Supply of Services (Implied Terms) Act 2003, and raises questions of broad importance for all contracts governed by Bermuda law – particularly as the decision has not been overturned in the years since, and remains the only authority to engage directly with the effect of section 6 of the 2003 Act; arguably its most important provision. The key issue that will be explored in this paper is whether the distinction drawn in Patton between contracting out of a duty of reasonable skill and care, and contracting out of liability for breach of that duty is, as a matter of contract law theory and jurisprudence, valid and meaningful, or whether it is a distinction without a difference.     

Failure of use of cemental annulations in teeth to determine the age of humans

The reliability of cemental annulation counts in teeth was examined to determine its value as an age indicator for humans. One hundred extracted human teeth were embedded in polyester casting resin and sectioned using a diamond wafering saw. Thin sections were photomicrographed, projected, and counted in a double blind random method of presentation. The age of the specimen was determined by adding the number of cemental annulations counted by the observers and the eruption age of the specific tooth that was used. The data analyzed by simple regression indicated that determining chronologic age in humans from cemental annulations is not possible.     

Comparison of the validity of three dental methods for the estimation of age at death

The aim of the present study was to compare the accuracy, precision, and bias of two macroscopic and one histological age at death estimation methods on human teeth. The sample was comprised of 67 permanent teeth, obtained from 37 individuals aged 20-91 years. Age was predicted according to the methods proposed by Lamendin et al. (LAM), Bang and Ramm (BR), and the quantification of tooth cementum annulations (TCA). TCA was found to be most accurate in all age groups. Its mean absolute error of the estimated age was about half as high as the mean absolute error for both LAM and BR. BR achieved approximately the same mean absolute error as TCA for old adults only. LAM displayed the highest precision in the young and the old age group whereas TCA was more precise in the middle age group. TCA was found to be the most precise method when the precision was calculated for all ages. Considering the bias, all methods displayed a tendency to overestimate age in young and to underestimate it in old specimens. The exception to this rule was TCA, which provided unbiased estimates for young adults. The higher accuracy and precision recommends favouring TCA over LAM and BR, provided that the required know-how and equipment are available.     

An investigation into the accuracy and reliability of skull-photo superimposition in a South African sample

One of the aims of forensic science is to determine the identities of victims of crime. In some cases the investigators may have ideas as to the identities of the victims and in these situations, ante mortem photographs of the victims could be used in order to try and establish identity through skull-photo superimposition. The aim of this study was to evaluate the accuracy of a newly developed digital photographic superimposition technique on a South African sample of cadaver photographs and skulls. Forty facial photographs were selected and for each photo, 10 skulls (including the skull corresponding to the photo) were used for superimposition. The investigator did not know which of the 10 skulls corresponded to the photograph in question. The skulls were scanned 3-dimensionally, using a Cyberware? Model 3030 Colour-3D Scanhead scanner. The photos were also scanned. Superimposition was done in 3D Studio Max and involved a morphological superimposition, whereby a skull is superimposed over the photo and assessed for a morphological match. Superimposition using selected anatomical landmarks was also performed to assess the match. A total of 400 skull-photo superimpositions were carried out using the morphological assessment and another 400 using the anatomical landmarks. In 85% of cases the correct skull was included in the possible matches for a particular photo using morphological assessment. However, in all of these cases, between zero and three other skulls out of 10 possibilities could also match a specific photo. In the landmark based assessment, the correct skull was included in 80% of cases. Once again, however, between one and seven other skulls out of 10 possibilities also matched the photo. This indicates that skull-photo superimposition has limited use in the identification of human skeletal remains, but may be useful as an initial screening tool. Corroborative techniques should also be used in the identification process.     

A View to the Future: A Novel Approach for 3D–3D Superimposition and Quantification of Differences for Identification from Next‐Generation Video Surveillance Systems

Techniques of 2D–3D superimposition are widely used in cases of personal identification from video surveillance systems. However, the progressive improvement of 3D image acquisition technology will enable operators to perform also 3D–3D facial superimposition. This study aims at analyzing the possible applications of 3D–3D superimposition to personal identification, although from a theoretical point of view. Twenty subjects underwent a facial 3D scan by stereophotogrammetry twice at different time periods. Scans were superimposed two by two according to nine landmarks, and root‐mean‐square (RMS) value of point‐to‐point distances was calculated. When the two superimposed models belonged to the same individual, RMS value was 2.10 mm, while it was 4.47 mm in mismatches with a statistically significant difference (p < 0.0001). This experiment shows the potential of 3D–3D superimposition: Further studies are needed to ascertain technical limits which may occur in practice and to improve methods useful in the forensic practice.     

Use of Craniofacial Superimposition in Historic Investigation

A skeleton discovered in Grand Forks, North Dakota was purported to belong to Clelland “Clell” Miller, a James‐Younger gang member, who was killed during the Northfield Bank robbery on September 7, 1876. A 3‐D image from a computer tomography (CT) scan of the skull was obtained, and a craniofacial superimposition was conducted to determine if the skull could belong to Miller. The superimposition method used in this case was to overlay the CT image of the skull onto Miller's postmortem photograph. In addition to the craniofacial superimposition, the images were juxtaposed to compare similarities or differences in facial morphology between the skull and photograph. Superimposition methods can be used to exclude identifications; however, they should not be used as a conclusive method for identification. In this case, there were sufficient similarities between the skull and Miller's photograph; therefore, the skull could not be eliminated as possibly being that of Miller.     

论我国民间借贷合同法律适用的民商区分

按照是否为自然人之间的借贷,《民间借贷司法解释》对利息约定不明的两种情形规定了不同的裁判规则。这种区分处理具有进步意义,但未能根据民商区分的理念作科学合理的区分,导致相关裁判规则存在标准混乱、规则缺失的问题。要确定民间借贷民商区分的判断标准,首先得解决民商区分的判断标准。我国应回避从内涵到外延都存在极大争议的商主体概念,借助“以营利为主要目的”的商行为概念及内涵和外延都确定的企业概念来界定商事法律关系,从而确定民商区分的法律适用难题。在确定了我国民商区分的判断标准后,民间借贷民商区分判断标准的厘定就迎刃而解了。据此,可确定民商区分视野下民间借贷纠纷裁判规则的完善方案。     

Differences in morphological age-related dental changes depending on postmortem interval.

Morphological methods for age estimation from teeth have been developed and applied to samples without taking the postmortem interval into consideration. We studied differences in morphological age-related changes between fresh extracted teeth and teeth from human skeletal remains in order to develop appropriate dental age estimation methods according to the time after death. Forty-three permanent teeth from dental patients were compared to 37 teeth obtained from human skeletal remains with a postmortem interval from 21 to 37 years. Morphological age-related changes were investigated by measuring variables on intact and half-sectioned teeth. A new computer assisted image analysis procedure to avoid subjectivity was developed to measure variables in sectioned specimens. Dental color, translucency length, attrition, cementum apposition, and secondary dentin showed higher values in teeth from human skeletal remains than in fresh extracted teeth. Variables obtained by morphometric analysis of computer-generated images (tooth length, tooth width, root length, and root area) showed higher values in fresh extracted teeth than in teeth from skeletal remains. The postmortem interval affects age-related morphological changes, and therefore different methods should be used for teeth of unknown postmortem interval.     

The placement of the human eyeball and canthi in craniofacial identification

An accurate understanding of the spatial relationships between the deep and superficial structures of the head is essential for anthropological methods concerned with the comparison of faces to skulls (superimposition) or the prediction of faces from them (facial approximation). However, differences of opinion exist concerning: (i) the position of the eyeball in planes other than the anteroposterior plane and (ii) the canthi positions relative to the bony orbital margins. This study attempts to clarify the above relationships by dissection of a small sample of adult human cadavers (N = 4, mean age = 83 years, s = 12 years). The most notable finding was that the eyeballs were not centrally positioned within the orbits as the more recent craniofacial identification literature expounds. Rather, the eyeballs were consistently positioned closer to the orbital roof and lateral orbital wall (by 1-2 mm on average); a finding consistent with the earlier anatomical literature. While these estimation errors are small ipsilaterally, several factors make them meaningful: (i) the orbital region is heavily used for facial recognition; (ii) the width error is doubled because the eyes are bilateral structures; (iii) the eyes are sometimes used to predict/assess other soft tissue facial structures; and (iv) the net error in facial approximation rapidly accumulates with the subsequent prediction of each independent facial feature. While the small sample size of this study limits conclusive generalizations, the new data presented here nonetheless have immediate application to craniofacial identification practice because the results are evidence based. In contrast, metric data have never been published to support the use of the central positioning guideline. Clearly, this study warrants further quantification of the eyeball position in larger samples and preferably of younger individuals.     

A test of individuality of human external ear pattern: its application in the field of personal identification

A preliminary study has been undertaken to test the individuality of human ear patterns and its probable use in profile view facial image recognition. Anthropometric measurements on 12 inter-landmark linear distances have been carried out for both left and right ears of 700 male and female individuals. A 12-dimensional feature space has been framed to represent each ear pattern as a feature vector with the measured inter-landmark distances as its components. The Euclidean distances in such a feature space amongst all possible pairs of ear patterns of both male and female individuals have been computed. Very few pairs have distances which fell below the safe distinction limit. The undistinguished pairs were further examined by direct superimposition of their images. None of the ear patterns is found to be exactly the same in morphology to the other. Even the left and right ears of the same individual are not identical. Thus, the present study reconfirms the individuality of ear patterns. For establishment of identity, a questioned profile view facial image can be compared with a control one on the basis of the ear pattern visible in it.     

Application Discourse and the Special Case-Thesis*

Abstract. Klaus Günther's (1988) book developed the distinction between two kinds of discourse, the foundation discourse and the application discourse. In an article (Günther 1989a) following the publication of the book, he used this basic distinction as the starting point for a criticism of the special case-thesis as defended by Robert Alexy (1978, 32ff., 263ff.; Alexy 1989, 16ff., 213ff.). The aim of this article is to criticize this criticism in its turn and to show that the special case-thesis does not need the reformulation which Günther proposes. It should be clear from the outset that this concerns an internal discussion in the field of discourse theory; certain discourse-theoretical premises are taken for granted. In order to understand Giinther's criticism I will first give a brief account of the distinction he has made.     

谈新编语文词典应有的特色

2004年出版的<现代汉语规范词典>有功能拓展延伸,收词充实丰富,释义更准确、周密、简洁、通俗等特点.该词典也存在着几个可商榷的问题:1.关于单字和单字义项区分词与非词的问题,2.关于词语该讲的用法问题,3.关于释文与词性的吻合问题,4.关于互见条的照应问题.     

Measuring the distance of the wisdom teeth from the occlusal plane as forensic-odontological method for chronological age determination

As part of an epidemiological study on tooth eruption it was attempted to define easily accessible criteria for age estimation in living human beings based on the distance of the wisdom teeth from the occlusal plane. 253 cast models of 149 female and 104 male patients were used for evaluation. Due to the great variability observed in the eruption of the wisdom teeth, only a small fraction of the total number of 10,924 cast models was suitable for investigation. Only teeth with the axis being perpendicular to the plane of occlusion during eruption according to radiological and clinical findings were included. After defining these inclusion criteria, the distance of the wisdom teeth from the plane of occlusion was determined and correlated to the age of the subjects. The results confirmed the known large variability concerning wisdom tooth eruption and did not show any reliable relation between age and distance values. Nevertheless, a remarkable finding that may be relevant for forensic odontostomatology was seen in one case where the lower wisdom teeth were taller than the occlusal plane, although the female patient was younger than 14 years. The upper molars were retained and root development was incomplete.     

Development of equipment for the standardization of skull photographs in personal identifications by photographic superimposition

The technique of photographic superimposition of postmortem specimens (dried skull or head) positioned identically to the orientation in an antemortem smiling photograph is now a recognized method for personal identification of human remains. Previous methods used to produce the postmortem photographs were problematic as orientation of the specimen could not be easily adjusted and positions were not reproducible. The objective of this paper is to describe the design and method of use of purpose-constructed equipment intended to alleviate these problems. The equipment comprises a skull-holding jig based conceptually on the Royal Berkshire Hospital halo frame. This is mounted on a pan-and-tilt device, incorporating calibrated measurement scales, enabling independent movements in each of the Cartesian coordinates. A camera is attached to an adjustable mount running on twin parallel rails allowing the camera-to-specimen distance to be varied. The equipment has proven to be straightforward in use and offers considerable advantages over previously described methods for producing postmortem photographs.     

面部整容术对颅像重合的影响分析

颅像重合法对身源不明的颅骨个体识别已在国内开展二十余年,其依据是对送检的失踪人照片面部软组织与颅骨之间标志点、线的对应量度关系做出是否同一人的认定。经多年观察总结面部整容术的方法、部位及形态与颅像重合标志点、线量度间的影响问题,对于人群中是否有部分人是面部整容术后的面像判断,提出相关专业人员的鉴定分析方法。     

Tricyclic Antidepressants Found in Pilots Fatally Injured in Civil Aviation Accidents

Prevalence of tricyclic antidepressants (TCAs) has not been explored in pilots. The National Transportation Safety Board (NTSB) aviation accident and the Federal Aviation Administration's Civil Aerospace Medical Institute (CAMI) toxicology and medical certification databases were searched for pilots fatally injured in aviation accidents. During 1990–2012, CAMI received bio‐samples of pilots from 7037 aviation accidents. Of these, 2644 cases were positive for drugs. TCAs were present in 31. TCA blood concentrations ranged from therapeutic to toxic levels. The NTSB determined that the use of drugs and ethanol as the probable cause or contributing factor in 35% (11 of 31) of the accidents. None of the 31 pilots reported the use of TCAs during their aviation medical examination. The prevalence of TCAs in aviators was less than 0.5% (31 of 7037 cases). There is a need for aviators to fully disclose the use of medications at the time of their medical examination.     

经济法之人性价值

就经济法产生的逻辑及主要内容考察,经济法是“人性冲突与调适”的法律形式。就实践而言,经济法产生于市场失灵,而市场失灵的深刻原因在于市场领域内人性的冲突;就立法而言,经济法产生于民法失灵,而民法失灵的真正根源在于民法注重人性解放的同时,对人性的反映也有一定的片面性。因此,经济法应当从厚重的“纯经济色彩”的层层包裹中破壳而出,复归人性之路。     

The uniqueness of the human anterior dentition: a geometric morphometric analysis

The analysis of bitemarks has a significant bearing on forensic odontology and has attracted an increasingly sophisticated array of techniques in its evaluation. Two postulates underlie all bitemark analyses: firstly, that the characteristics of the anterior teeth involved in the bite are unique, and secondly, that this uniqueness is accurately recorded in the material bitten. Here, we investigate the question of the uniqueness of the anterior dentition. To do this, we use geometric morphometric techniques based on landmark and semilandmark data. The incisor and canine occlusal surfaces of 50 randomly selected orthodontic casts of young individuals (17-20 years) of both sexes form the material for this study. We analyzed the sizes of these teeth by means of landmark and semilandmark analysis to calculate Procrustes distances between tooth outlines. In order to analyze shape variation among individuals, we carried out principal components analyses on the partial warp scores. These are derived from Partial Procrustes coordinates aligned by means of thin-plate spline decomposition based on the bending energy matrix. The results indicate that there is no sexual dimorphism in the shape of the upper or lower arches. Plots of centroid size and first relative warps show less superposition among individuals than in shape analysis. This means that, when the size and shape are considered together, the difference between arches increases. Procrustes superimposition between the two individuals located most closely (0.0444) and the two most separated (0.1567) along the first axis of relative warp analyses show that individuals are not only differentiated by the relative position of their teeth but also by their arch shape. In conclusion, it appears that the incisal surfaces of the anterior dentition are in fact unique.