The Successful Recovery of Low Copy Number and Degraded DNA from Bones Exposed to Seawater Suitable for Generating a DNA STR Profile

A universal method allowing for DNA profiling from bones exposed to seawater has not been reported yet. This study refers on the identification of a body immersed in seawater for 8 months. The biological material for identification was the mandibular body, usually characterized by low success rates of DNA analysis. Initially, two extraction protocols were performed with negative results: one used for bones immersed in fresh water and a silica‐column procedure. A third protocol was performed, which combined the extraction of a higher amount of bone powder, the use of multi‐silica‐based extraction columns followed by a concentration step. This protocol allowed to obtain low copy number DNA and to generate a 12‐loci STR profile by combining conventional STR typing and mini‐STR technologies. This protocol could be suitable when human bones have been exposed to severe environmental conditions, and the available nuclear DNA is highly degraded and in low copy number.     

Mandibular ramus: an indicator for sex in fragmentary mandible

Mandible is the hardest and most durable bone of the skull exhibiting a high degree of sexual dimorphism. Especially ramus of mandible is subjected to greater stress than any other bone of the skull because of the process of mastication. This study has been performed to establish the osteometric standards for practical use in forensic context over Indian population using mandibular ramus. The sample consists of 116 mandibles of Northern Indian population (M:F; 92:24, mean age 37.4 years), collected from the Department of Forensic Medicine, IMS, BHU, Varanasi. Osteometric informations about five metric parameters (coronoid height, projective height, condylar height, and maximum breadth and minimum breadth of ramus) were taken with sliding calipers. These parameters were subjected to different discriminant function analysis using SPSS 16.0. All parameters showed significant sexual dimorphism (p < 0.001 in all cases) with an overall accuracy of 80.2%, and coronoid height was the single best parameter providing an accuracy of 74.1%.     

Cone‐beam Computed Tomography for Analyzing Variations in Inferior Alveolar Canal Location in Adults in Relation to Age and Sex*

Abstract: Previous studies have indicated that the relative position of the inferior alveolar canal and its mental and mandibular foramina in adults vary with age and show sexual dimorphism. Conceivably, these purported differences could be of forensic value for determining identity of human remains. This study was designed to determine the influence of age and sex on the relative position of inferior alveolar canal and its foramina in cone‐beam computed tomography (CBCT) studies of adults. Existing CBCT studies of the maxillofacial region from dentate adult patients selected at random and ranging in age from 18 to 80 years (110 women and 55 men) were acquired, and the location of the inferior alveolar canal was assessed at three points: the mandibular foramen in axial view, the inferior alveolar canal in coronal view, and the mental foramen in coronal view. Measurements were also expressed for the mental foramen as the percentile position from the nearest superior bony crest to the inferior border; corresponding position of the mandibular foramen from the anterior to the posterior border of the mandibular ramus; and for the inferior alveolar canal at the level of first permanent molar from the nearest buccal bony surface to the lingual surface and from the superior alveolar crest to the inferior border. Regression analyses were performed on the variables with regard to the effects of age and sex. Most analyses resulted in no statistical significance (p < 0.05). A few of the sex‐specific traits demonstrated near‐statistically significant effects; however, these characterizations generally resulted in a 1% or less change per age decade. Overall, the results demonstrated that the relative location of the inferior alveolar canal and associated foramina in adults remain fairly constant without regard to age and sex.     

Introducing Human Mandible Identification [(hu)MANid]: A Free,Web‐Based GUI to Classify Human Mandibles

Statistical programs have revolutionized the way in which forensic anthropologists conduct casework by allowing practitioners to use computationally complex analytics at the click of a button. Importantly, the products of these statistical programs are reproducible and contain measures of error or uncertainty, thereby strengthening conclusions. This paper is an introduction to (hu)MANid, a free, web‐based application that uses linear and mixture discriminant function analyses to classify human mandibles into one of many worldwide and/or periodic reference groups. The mechanics, development, and use of the application will be discussed. Further, the program was tested against other software to compare model performances and classifications. Total correct classifications among the test cases and programs were identical. Ten mandibles were tested using both statistical procedures. Mixture discriminant analysis improved classification by an average of 9.3% and correctly identified three more mandibles than LDA. Therefore, we believe (hu)MANid will be an asset to the anthropological community.     

Examining Interobserver Reliability of Metric and Morphoscopic Characteristics of the Mandible

Mandibular metric and morphological characteristics have long been used for sex and ancestry estimation. Currently, there are no large‐scale studies examining interobserver agreement, particularly examining the role of observer experience. This study examines the interobserver agreement of six morphoscopic and eleven metric mandibular variables. Four observers with varied levels of experience scored 183 mandibles from the William M. Bass Donated Skeletal Collection. Absolute agreement and consistency were evaluated with the intraclass correlation coefficient (ICC). Additionally, technical error of measurement (TEM) and relative TEM (%TEM) were calculated for each metric variable. All analyses were conducted twice—once with all observers and again with only experienced observers. Results show mean morphoscopic agreement of 0.543 among all observers and 0.615 for experienced observers, and mean metric agreement of 0.886 among all observers and 0.911 for experienced observers. Further, no TEM exceeded 2 mm. All results were significant (p < 0.001).     

根据成人的耻骨缘枝角和耻骨联合部宽高指数鉴定性别

笔者测量了100副(男、女各50副)成人耻骨缘枝角的角度和耻骨联合部宽高的指数,其男女均数差异极为显著。从总体上看,耻骨缘枝角男性大于女性,耻骨联合部宽高的指数男性小于女性。提出前者的性别判别值为137.0°,后者的性别判别值为62.2。估算其正确率分别可达97.7％和81.6％。     

Accuracy of BR Regression Equation for Impacted Teeth in Age Estimation in Haryana Population of India

Abstract:  Dental cementum is a vital tissue that demonstrates continuous apposition throughout the life of a tooth. Positive correlation has been reported between the coronal displacement of cementum and age in impacted teeth and BR regression equation has been proposed. The present study is an attempt to calculate accuracy of BR regression equation in Haryana population of India. The study was conducted on 20 impacted mandibular third molars extracted from healthy patients, aged between 22 and 32 years. The bucco-lingual ground sections were prepared and the distance between the edges of enamel and cementum were measured with micrometer attached to a light microscope and BR regression equation was applied for age estimation. Although the estimated age with BR regression equation was less than chronological age it was not statistically significant. Hence, the BR regression equation can be used in medicolegal as well as in forensic odontology for age estimation.