Variation in proportion indices and angles between selected facial landmarks with rotation in the Frankfort plane

A number of different techniques are employed in facial image comparison of living persons. In this study, the effect of rotation on angles and proportion indices between selected facial landmarks is evaluated as a first step to assess whether facial anthropometry could be usefully applied to facial image comparison. The faces of five volunteers were photographed in the Frankfort plane at different angles of rotation from 0 degree (frontal) to 90 degrees (side view), rotating every 10 degrees both clockwise and counter-clockwise. Four landmarks were used: right and left ectocanthions, nasion, and stomion. The proportion indices of the measurements between these landmarks were calculated as well as the angles created by the lines connecting the same landmarks. The results show a consistent and predictable variation between the five subjects. With rotation, the greatest variation is seen where horizontal landmark connecting lines are combined with the ectocanthion/ stomion lines or nasion/stomion. There is less variation in the proportion indices for vertical and diagonally orientated landmark connecting lines.     

Facial image comparisons of morphed facial imagery

ABSTRACT

Facial image morphing is a technique whereby two or more faces are blended together to create a new face (the morph). Apps and open source software are now freely available to create morphs. While morph creation is predominantly for entertainment value, it is also a method being used to create facial imagery for use on fraudulent identity documents. This study sought to answer two questions. First, would participants accept a morph persona (an identity created using only morphed facial imagery) as a credible identity? Second, could participants match faces that had been used to create a morph (so-called constituent faces)? Results showed that morph personas were credible, being correctly matched more often than alternative images of real people. Further, results showed that propensity to declare a constituent face a match to its morph was dependent on the type of morph, with morphs made using two faces more likely to yield matches than those made using eight or 16 faces. A follow up similarity study on faces selected showed that even if a constituent face was selected it would more than likely have been ruled out as a match following a more thorough one-to-one comparison.     

Anthropometric and anthroposcopic analysis of different shapes of faces in group of Indian population: a pilot study

Focus of facial identification research is to isolate features that can be considered a factor of individualization. Anthropometry and Anthroposcopy have been the most important research tools in the field of forensic anthropology. These two methods of observation and data collection are made both on the living and on skeletonized human remains. Anthropometry is a systematic study of human measurements. Morphological analysis of unmeasurable features usually is the area of anthroposcopy. Hence, this study aims to assess different human faces using anthropometry and anthroposcopy. A total of 100 subjects were included in the study, prosopic index given by Martin and Saller was used to classify facial types. An anthropometric measurement was used to assess the facial proportions and anthroposcopy for facial morphology. A significant number of subjects were of hyperleptoprosopic facial type, and with a significant sexual dimorphism observed among the Indian population. Anthroposopic analysis showed common morphological features in each prosopic indices. The findings in our study may throw light on anthropometric and anthroposcopic features of Indians and help significantly in the field of forensic anthropology.     

Techniques in facial identification: Computer-aided facial reconstruction using a laser scanner and video superimposition

A facial image was reconstructed from the skull, part of a complete skeleton found in woodland, of a male person who had hanged himself from a tree. In addition, video superimposition was carried out with antemortem photographs of a person suspected of being the victim, and a good match was obtained. In a further case, a cheaper video-transparency superimposition was carried out, with identity later being confirmed on the basis of dental records. The techniques and the problems encountered are discussed. According to our experience, 3D computer reconstruction and video superimposition have a useful role in the process of identification, particularly in the early stages of an investigation and when other more definitive methods may not be available.     

Assessment of some problematic factors in facial image identification using a 2D/3D superimposition technique

The number of criminal cases requiring facial image identification of a suspect has been increasing because a surveillance camera is installed everywhere in the city and furthermore, the intercom with the recording function is installed in the home. In this study, we aimed to analyze the usefulness of a 2D/3D facial image superimposition system for image identification when facial aging, facial expression, and twins are under consideration. As a result, the mean values of the average distances calculated from the 16 anatomical landmarks between the 3D facial images of the 50s groups and the 2D facial images of the 20s, 30s, and 40s groups were 2.6, 2.3, and 2.2 mm, respectively (facial aging). The mean values of the average distances calculated from 12 anatomical landmarks between the 3D normal facial images and four emotional expressions were 4.9 (laughter), 2.9 (anger), 2.9 (sadness), and 3.6 mm (surprised), respectively (facial expressions). The average distance obtained from 11 anatomical landmarks between the same person in twins was 1.1 mm, while the average distance between different person in twins was 2.0 mm (twins). Facial image identification using the 2D/3D facial image superimposition system demonstrated adequate statistical power and identified an individual with high accuracy, suggesting its usefulness. However, computer technology concerning video image processing and superimpose progress, there is a need to keep familiar with the morphology and anatomy as its base.     

Geometric facial comparisons in speed-check photographs

In many cases, it is not possible to call the motorists to account for their considerable excess in speeding, because they deny being the driver on the speed-check photograph. An anthropological comparison of facial features using a photo-to-photo comparison can be very difficult depending on the quality of the photographs. One difficulty of that analysis method is that the comparison photographs of the presumed driver are taken with a different camera or camera lens and from a different angle than for the speed-check photo. To take a comparison photograph with exactly the same camera setup is almost impossible. Therefore, only an imprecise comparison of the individual facial features is possible. The geometry and position of each facial feature, for example the distances between the eyes or the positions of the ears, etc., cannot be taken into consideration. We applied a new method using 3D laser scanning, optical surface digitalization, and photogrammetric calculation of the speed-check photo, which enables a geometric comparison. Thus, the influence of the focal length and the distortion of the objective lens are eliminated and the precise position and the viewing direction of the speed-check camera are calculated. Even in cases of low-quality images or when the face of the driver is partly hidden, good results are delivered using this method. This new method, Geometric Comparison, is evaluated and validated in a prepared study which is described in this article.     

Toward DNA-based facial composites: Preliminary results and validation

The potential of constructing useful DNA-based facial composites is forensically of great interest. Given the significant identity information coded in the human face these predictions could help investigations out of an impasse. Although, there is substantial evidence that much of the total variation in facial features is genetically mediated, the discovery of which genes and gene variants underlie normal facial variation has been hampered primarily by the multipartite nature of facial variation. Traditionally, such physical complexity is simplified by simple scalar measurements defined a priori, such as nose or mouth width or alternatively using dimensionality reduction techniques such as principal component analysis where each principal coordinate is then treated as a scalar trait. However, as shown in previous and related work, a more impartial and systematic approach to modeling facial morphology is available and can facilitate both the gene discovery steps, as we recently showed, and DNA-based facial composite construction, as we show here. We first use genomic ancestry and sex to create a base-face, which is simply an average sex and ancestry matched face. Subsequently, the effects of 24 individual SNPs that have been shown to have significant effects on facial variation are overlaid on the base-face forming the predicted-face in a process akin to a photomontage or image blending. We next evaluate the accuracy of predicted faces using cross-validation. Physical accuracy of the facial predictions either locally in particular parts of the face or in terms of overall similarity is mainly determined by sex and genomic ancestry. The SNP-effects maintain the physical accuracy while significantly increasing the distinctiveness of the facial predictions, which would be expected to reduce false positives in perceptual identification tasks. To the best of our knowledge this is the first effort at generating facial composites from DNA and the results are preliminary but certainly promising, especially considering the limited amount of genetic information about the face contained in these 24 SNPs. This approach can incorporate additional SNPs as these are discovered and their effects documented. In this context we discuss three main avenues of research: expanding our knowledge of the genetic architecture of facial morphology, improving the predictive modeling of facial morphology by exploring and incorporating alternative prediction models, and increasing the value of the results through the weighted encoding of physical measurements in terms of human perception of faces.     

A new computer-assisted technique to aid personal identification

The paper describes a procedure aimed at identification from two-dimensional (2D) images (video-surveillance tapes, for example) by comparison with a three-dimensional (3D) facial model of a suspect. The application is intended to provide a tool which can help in analyzing compatibility or incompatibility between a criminal and a suspect’s facial traits. The authors apply the concept of “geometrically compatible images”. The idea is to use a scanner to reconstruct a 3D facial model of a suspect and to compare it to a frame extracted from the video-surveillance sequence which shows the face of the perpetrator. Repositioning and reorientation of the 3D model according to subject’s face framed in the crime scene photo are manually accomplished, after automatic resizing. Repositioning and reorientation are performed in correspondence of anthropometric landmarks, distinctive for that person and detected both on the 2D face and on the 3D model. In this way, the superimposition between the original two-dimensional facial image and the three-dimensional one is obtained and a judgment is formulated by an expert on the basis of the fit between the anatomical facial districts of the two subjects. The procedure reduces the influence of face orientation and may be a useful tool in identification.     

Geometric morphometric methods for three-dimensional virtual reconstruction of a fragmented cranium: the case of Angelo Poliziano

The process of forensic identification of missing individuals is frequently reliant on the superimposition of cranial remains onto an individual's picture and/or facial reconstruction. In the latter, the integrity of the skull or a cranium is an important factor in successful identification. Here, we recommend the usage of computerized virtual reconstruction and geometric morphometrics for the purposes of individual reconstruction and identification in forensics. We apply these methods to reconstruct a complete cranium from facial remains that allegedly belong to the famous Italian humanist of the fifteenth century, Angelo Poliziano (1454–1494). Raw data was obtained by computed tomography scans of the Poliziano face and a complete reference skull of a 37-year-old Italian male. Given that the amount of distortion of the facial remains is unknown, two reconstructions are proposed: The first calculates the average shape between the original and its reflection, and the second discards the less preserved left side of the cranium under the assumption that there is no deformation on the right. Both reconstructions perform well in the superimposition with the original preserved facial surface in a virtual environment. The reconstruction by means of averaging between the original and reflection yielded better results during the superimposition with portraits of Poliziano. We argue that the combination of computerized virtual reconstruction and geometric morphometric methods offers a number of advantages over traditional plastic reconstruction, among which are speed, reproducibility, easiness of manipulation when superimposing with pictures in virtual environment, and assumptions control. S. Benazzi and E. Stansfield contributed equally to this work.     

Craniofacial superimposition: a review of focus distance estimation methods and an extension to profile view photographs

International Journal of Legal Medicine - Craniofacial superimposition concerns the photographic overlay of skulls and faces, for skeletal identification. As a phased method that depends on...     

In vivo facial soft tissue thickness measurements for Turkish Subadults

Facial soft tissue thicknesses are mainly used in facial reconstruction for the purpose of forensic identification. Several studies of facial soft tissue thickness (FSTT) in subadults have been published from different ancestral backgrounds such as Caucasoid, African-American, Hispanics and Japanese subjects. However, there is no existing available FSTT data for Turkish subadults. This study reports FSTT data in Turkish subadults of both sexes, aged between 3 and 18. FSTTs were measured at 31 anatomical points on the faces of 450 individuals. A table of mean FSTTs was developed for boys and girls divided into three age groups (3–8; 9–13; 14–18). Differences between boy and girl measurements in three age groups were compared using Student’s t-test. Significant differences were observed at some landmarks in each age group. In order to observe differences among age groups, an ANOVA (one-way analyses of variance) followed by a LSD (least significant difference) Post Hoc test was applied to the variances. The boys showed a general increase in tissue thickness with an increase at all the midline and cheek points. The girls showed increased tissue thickness with age at all points except supraglabella, upper lip, frontal eminence, lateral nasal, sub-orbital and supraglenoid.     

Holographic topometry for a dense visualization of soft tissue for facial reconstruction

Facial reconstruction can be used as a forensic technique to identify a person, when no other identification method is applicable. The facial soft tissue thickness applied to the skull is crucial when performing an accurate facial reconstruction. Historically, scientists developed several techniques to measure the soft tissue of the face. It was their aim, to build a database of a unique point-set, differentiated by gender, age, ethnic origin, BMI. All used a limited number of landmarks and an inaccurate measuring technique. We developed a contact-free and precise measuring technique, using low-dose CT and holographic data. Due to the extremely short exposure time, the holographic measurement is very precise. We lay out our first experiences to create a facial soft tissue layer map of the face.     

Magnetic resonance imaging of facial muscles

Facial and tongue muscles are commonly involved in patients with neuromuscular disorders. However, these muscles are not as easily accessible for biopsy and pathological examination as limb muscles. We have previously investigated myasthenia gravis patients with MuSK antibodies for facial and tongue muscle atrophy using different magnetic resonance imaging sequences, including ultrashort echo time techniques and image analysis tools that allowed us to obtain quantitative assessments of facial muscles. This imaging study had shown that facial muscle measurement is possible and that useful information can be obtained using a quantitative approach. In this paper we aim to review in detail the methods that we applied to our study, to enable clinicians to study these muscles within the domain of neuromuscular disease, oncological or head and neck specialties. Quantitative assessment of the facial musculature may be of value in improving the understanding of pathological processes occurring within facial muscles in certain neuromuscular disorders.     

Pitfalls at the root of facial assessment on photographs: a quantitative study of accuracy in positioning facial landmarks

In the last years, facial analysis has gained great interest also for forensic anthropology. The application of facial landmarks may bring about relevant advantages for the analysis of 2D images by measuring distances and extracting quantitative indices. However, this is a complex task which depends upon the variability in positioning facial landmarks. In addition, literature provides only general indications concerning the reliability in positioning facial landmarks on photographic material, and no study is available concerning the specific errors which may be encountered in such an operation. The aim of this study is to analyze the inter- and intra-observer error in defining facial landmarks on photographs by using a software specifically developed for this purpose. Twenty-four operators were requested to define 22 facial landmarks on frontal view photographs and 11 on lateral view images; in addition, three operators repeated the procedure on the same photographs 20 times (at distance of 24 h). In the frontal view, the landmarks with less dispersion were the pupil, cheilion, endocanthion, and stomion (sto), and the landmarks with the highest dispersion were gonion, zygion, frontotemporale, tragion, and selion (se). In the lateral view, the landmarks with the least dispersion were se, pronasale, subnasale, and sto, whereas landmarks with the highest dispersion were gnathion, pogonion, and tragion. Results confirm that few anatomical points can be defined with the highest accuracy and show the importance of the preliminary investigation of reliability in positioning facial landmarks.     

Intoxicated person discrimination using infrared signature of facial blood vessels

In this work, facial thermal infrared images are employed for intoxicated person discrimination. The activity of the facial blood vessels of sober and intoxicated people comes into sight when nonlinear anisotropic diffusion and top-hat transformation are applied to enhance and isolate the vessels from the rest of the information on the face. For an intoxicated person, vessels around the nose and eyes as well as on the forehead become more active, whereas for a person who is sober the vessels’ activity is smoother all over the face’s thermal image. Accordingly, drunkenness can be ascertained by only using the thermal infrared image of the intoxicated person. The proposed method can be incorporated into a non-invasive inspection system used by the police as a first step for intoxicated person detection. The Student’s t-test is employed to assess the degree of confidence in separating the thermal images corresponding to sober and intoxicated people. The 40 participants in the experiment have contributed to the creation of the unique sober–drunk database available on the web.     

The conclusive role of postmortem computed tomography (CT) of the skull and computer-assisted superimposition in identification of an unknown body

Computed tomography is commonly used in modern medicine, and thus, it is often helpful for medicolegal purposes, especially as part of the antemortem record. The application of postmortem computed tomography and 3D reconstruction of the skull in challenging cases is reported, and its valuable contribution to positive identification is discussed. This paper presents a case in which the body of an unknown individual is identified. Positive identification had not been possible despite a multidisciplinary examination. The postmortem use of computerized tomography and 3D reconstruction of the skull followed by the comparison of individual morphological characteristics of the viscerocranium showed the concordant points between the deceased and a missing person. Finally, superimposition using a 3D-reconstructed skull instead of the skeletonized skull demonstrated an adequate degree of morphological consistency in the facial images of the analyzed individuals that lead to positive identification. It was concluded that where other methods of personal identification had failed, the use of postmortem computed tomography had proved to be instrumental in the positive identification of the deceased.     

Dental superimposition: a pilot study for standardising the method

Dental superimposition is becoming more and more important because of the increasing number of illegal immigrants (at least in Italy), with no clinical history, no personal effects or relatives useful for genetic comparison, whose friends and acquaintances can usually only produce photographs. Very few authors have been involved in devising and using this method. The goal of the present study is to establish whether it is possible, and under which conditions, to identify individuals by dental superimposition of teeth visible in an ante-mortem photograph and dental casts of an unidentified body, and to develop a protocol for the spatial orientation analysis of the dentition and qualitative and semi-quantitative analysis of superimpositions. A non-mathematical scoring system has been applied to each superimposition as a first step towards the optimisation of a cheap, quick, semi-quantitative method of identifying individuals when other more used methods are not applicable.     

Human identification through frontal sinus 3D superimposition: Pilot study with Cone Beam Computer Tomography

As a unique anatomical feature of the human body, the frontal sinus morphology has been used for identification of unknown bodies with many techniques, mostly using 2D postero-anterior X-rays. With the increase of the use of Cone-Beam Computer Tomography (CBCT), the availability of this exam as ante-mortem records should be considered. The purpose of this study is to establish a new technique for frontal sinus identification through direct superimposition of 3D volumetric models obtained from CBCT exam, by testing two distinct situations. First, a reproducibility test, where two observers independently rendered models of frontal sinus from a sample 20 CBCT exams and identified them on each other's list. In the second situation, one observer tested the protocol and established on different exams of three individual. Using the open source DICOM viewer InVesallius^® for rendering, Mesh Lab^®, for positioning the models and CloudCompare for volumetric comparison, both observers matched cases with 100% accuracy and the level of coincidence in a identification situation. The uniqueness of the frontal sinus topography is remarkable and through the described technique, can be used in forensic as an identification method whenever both the sinus structure and antemortem computer tomography is available.     

兔面神经爆炸性损伤的病理学变化

目的　研究兔面神经爆炸伤的损伤情况及相关病理变化。方法　选用点状爆炸源 ,距新西兰白兔面部 2mm处引爆致伤。分别于伤后 6小时、1天、3天、1周、2周取面神经 ,在光镜、电镜下观察神经轴突、髓鞘、雪旺细胞及神经纤维周围结缔组织的变化。结果　 0 .12 5gTNT当量炸药球距兔左面部 2mm处引爆 ,致兔面部软组织挫裂伤、下颌骨粉碎性骨折。伤后动物出现面瘫症状 ,但面神经连续性较好。伤后 1天光镜下观察 ,面神经轴突肿胀 ,但神经外膜延续性尚好 ,并有大量炎细胞弥散浸润。伤后 3天出现髓鞘空泡样变 ,板层分离 ,轴索发生广泛肿胀、断裂。伤后 1周轴索染色不均 ,坏死崩解 ,炎症开始消退。伤后 2周时未见明显轴索再生。结论　面神经爆炸伤以严重的神经干间接伤为主 ,其范围广泛 ,轴索及髓鞘出现相应病理改变 ,伤后 1周内神经损伤随时间加重     

面神经炎中医分型治疗效果观察

 目的 观察面神经炎中医分型治疗效果。方法 95例面神经炎患者按1∶1的比例随机分为两组,治疗组48例,对照组47例。两组均按急性期、静止期及恢复期采用不同的针刺方法。同时,治疗组将患者分为风寒客络型、风热袭络型及瘀阻络脉型,在牵正散的基础上风寒客络型加防风、羌活、桂枝、黄芪;风热袭络型加黄芩、菊花、夏枯草;瘀阻络脉型加当归、赤芍、香附等中药治疗。对照组不分证型,只服用牵正散中药。治疗6周后,比较两组的疗效及面神经功能积分。结果 从临床疗效比较,治疗组临床治愈率为83.3%,明显优于对照组74.4%(P＜0.01),而在总有效率方面,两组无统计学差异。治疗6周后,两组患者面神经运动功能、语言功能及综合功能均较前有所提高(P＜0.05),且与对照组相比,治疗组患者面神经运动功能、语言功能及综合功能有所提高(P<0.05)。结论 面神经炎中医分型治疗能显著改善预后。