人体面部形态特征的研究进展

而部形态特征研究在很多学科中都具有重要作用,例如雕塑学、考^学、医学美容、法医学颅骨面貌复原等。随着计算机技术的快速发展,使得面貌复原技术也大大提高,同时,对五官形态特衙的要求也相应提高。现就国内外在人体而部形态特征相关研究作一概述。     

Tests of one Brazilian facial reconstruction method using three soft tissue depth sets and familiar assessors

Facial reconstruction is a method that seeks to recreate a person's facial appearance from his/her skull. This technique can be the last resource used in a forensic investigation, when identification techniques such as DNA analysis, dental records, fingerprints and radiographic comparison cannot be used to identify a body or skeletal remains. To perform facial reconstruction, the data of facial soft tissue thickness are necessary. Scientific literature has described differences in the thickness of facial soft tissue between ethnic groups. There are different databases of soft tissue thickness published in the scientific literature. There are no literature records of facial reconstruction works carried out with data of soft tissues obtained from samples of Brazilian subjects. There are also no reports of digital forensic facial reconstruction performed in Brazil. There are two databases of soft tissue thickness published for the Brazilian population: one obtained from measurements performed in fresh cadavers (fresh cadavers' pattern), and another from measurements using magnetic resonance imaging (Magnetic Resonance pattern). This study aims to perform three different characterized digital forensic facial reconstructions (with hair, eyelashes and eyebrows) of a Brazilian subject (based on an international pattern and two Brazilian patterns for soft facial tissue thickness), and evaluate the digital forensic facial reconstructions comparing them to photos of the individual and other nine subjects. The DICOM data of the Computed Tomography (CT) donated by a volunteer were converted into stereolitography (STL) files and used for the creation of the digital facial reconstructions. Once the three reconstructions were performed, they were compared to photographs of the subject who had the face reconstructed and nine other subjects. Thirty examiners participated in this recognition process. The target subject was recognized by 26.67% of the examiners in the reconstruction performed with the Brazilian Magnetic Resonance Pattern, 23.33% in the reconstruction performed with the Brazilian Fresh Cadavers Pattern and 20.00% in the reconstruction performed with the International Pattern, in which the target-subject was the most recognized subject in the first two patterns. The rate of correct recognitions of the target subject indicate that the digital forensic facial reconstruction, conducted with parameters used in this study, may be a useful tool.     

Ultrasonic assessment of facial soft tissue thicknesses in adult Egyptians

The production of a three-dimensional plastic face on an unknown human skull has been practiced sporadically since the latter part of the last century. In recent years, the technique has been revived and applied to forensic science cases. The morphometric method of forensic facial reconstruction rests heavily on the use of facial soft tissue depth measurements. Moreover, it has been established that measurements made on the living are of more value than those made on the dead. In view of the well-known genetic complexities of the Egyptians, and the lack of knowledge of average facial soft tissue depths of the Egyptians that makes facial reconstruction questionable, it was decided to set up a table of norms for facial tissue thicknesses in 204 adult Egyptians aged 20-35 years. Tissue depths at 17 established landmarks (according to Aulsebrook et al. [Forensic Sci. Int. 79 (1996) 83]) were obtained using ultrasonic probing. The study revealed a unique spectrum of measurements for the Egyptians that might be useful for facial reconstruction purposes with obvious sexual dimorphism in facial soft tissue thickness. Additionally, the study provided evidence for the presence of interpopulation differences in average facial soft tissue thicknesses as evidenced from the comparison of the present data of Egyptians with those previously reported for some other populations.     

A novel method of automated skull registration for forensic facial approximation

Modern forensic facial reconstruction techniques are based on an understanding of skeletal variation and tissue depths. These techniques rely upon a skilled practitioner interpreting limited data. To (i) increase the amount of data available and (ii) lessen the subjective interpretation, we use medical imaging and statistical techniques. We introduce a software tool, reality enhancement/facial approximation by computational estimation (RE/FACE) for computer-based forensic facial reconstruction. The tool applies innovative computer-based techniques to a database of human head computed tomography (CT) scans in order to derive a statistical approximation of the soft tissue structure of a questioned skull. A core component of this tool is an algorithm for removing the variation in facial structure due to skeletal variation. This method uses models derived from the CT scans and does not require manual measurement or placement of landmarks. It does not require tissue-depth tables, can be tailored to specific racial categories by adding CT scans, and removes much of the subjectivity of manual reconstructions.     

Application of 3-D computer graphics for facial reconstruction and comparison with sculpting techniques

Facial reconstruction has until now been carried out by the sculpting technique. This method involves building a face with clay or other suitable material on to a skull or its cast, taking into account appropriate facial thickness measurements together with information provided by anthropologists such as approximate age, sex, race and other individual idiosyncrasies. A method for facial reconstruction is presented using 3-D computer graphics and is compared with the manual technique. The computer method involves initially digitising a skull using a laser scanner and video camera interfaced to a computer. A face, from a data bank which has previously digitised facial surfaces, is then placed over the skull in the form of a mask and the skin thickness is altered to conform with the underlying skull. The advantage of the computer method is its speed and flexibility. We have shown that the computer method for reconstructing a face is feasible and furthermore has the advantage over the manual technique of speed and flexibility. Nevertheless, the technique is far from perfect. Further facial thickness data needs collecting and the method requires evaluation using both known control skulls and later unknown remains.     

An accuracy assessment of forensic computerized facial reconstruction employing cone-beam computed tomography from live subjects

The utilization of 3D computerized systems has allowed more effective procedures for forensic facial reconstruction. Three 3D computerized facial reconstructions were produced using skull models from live adult Korean subjects to assess facial morphology prediction accuracy. The 3D skeletal and facial data were recorded from the subjects in an upright position using a cone-beam CT scanner. Shell-to-shell deviation maps were created using 3D surface comparison software, and the deviation errors between the reconstructed and target faces were measured. Results showed that 54%, 65%, and 77% of the three facial reconstruction surfaces had <2.5 mm of error when compared to the relevant target face. The average error for each reconstruction was -0.46 mm (SD = 2.81) for A, -0.31 mm (SD = 2.40) for B, and -0.49 mm (SD = 2.16) for C. The facial features of the reconstructions demonstrated good levels of accuracy compared to the target faces.     

Mid-facial tissue depths of white children: an aid in facial feature reconstruction

Available facial tissue thickness standards for facial feature reconstruction are based on adult measurements. Mid-facial tissue thicknesses for male and female white adolescents are presented here. Measurements were taken from lateral radiographs produced in an orthodontic practice. Statistical analysis indicates that age, sex, and to some extent, dental occlusion pattern are factors that should be taken into account when attempting facial feature reconstructions.     

计算机辅助技术的三维颅面复原研究现状与进展

本文主要论述了国内、外学者对人头颅面三维容貌复原技术的研究现状与研究的进展情况，并对国内、外目前的头颅复原研究现状和进展情况进行了比较与分析。     

Investigation into the use of photoanthropometry in facial image comparison

Photoanthropometry is a metric based facial image comparison technique. Measurements of the face are taken from an image using predetermined facial landmarks. Measurements are then converted to proportionality indices (PIs) and compared to PIs from another facial image. Photoanthropometry has been presented as a facial image comparison technique in UK courts for over 15 years. It is generally accepted that extrinsic factors (e.g. orientation of the head, camera angle and distance from the camera) can cause discrepancies in anthropometric measurements of the face from photographs. However there has been limited empirical research into quantifying the influence of such variables. The aim of this study was to determine the reliability of photoanthropometric measurements between different images of the same individual taken with different angulations of the camera. The study examined the facial measurements of 25 individuals from high resolution photographs, taken at different horizontal and vertical camera angles in a controlled environment. Results show that the degree of variability in facial measurements of the same individual due to variations in camera angle can be as great as the variability of facial measurements between different individuals. Results suggest that photoanthropometric facial comparison, as it is currently practiced, is unsuitable for elimination purposes. Preliminary investigations into the effects of distance from camera and image resolution in poor quality images suggest that such images are not an accurate representation of an individuals face, however further work is required.     

Measurement of eyeball protrusion and its application in facial reconstruction

The estimation of eyeball protrusion from the bony orbit has traditionally relied upon Wolff's theory (1976) that the cornea will be tangental to a line taken from the superior to the inferior orbital margin. This study tested this theory by taking measurements from MRI cranial images of 78 eyes of white adult subjects. Orbital depth had a significant negative linear correlation with eyeball protrusion, and protrusion of the eyeball was determined by the following standard: eyeball protrusion = 18.3 - (0.4 x orbit depth). Current eyeball position determination was shown to be as much as 3.9 mm too deep in the socket, and a practical application of this result to facial reconstruction is discussed.     

四川汉族青少年面部中线软组织厚度的数字X线测量

目的测量四川汉族青少年(8～20岁)人群面部中线软组织厚度,探讨其生长发育变化规律,为法医人类学的面部重建提供的基础数据。方法选取974例(男496,女478)头颅侧位数字X线片,分13个年龄段(8～20岁),选择面部10个标志点的软组织厚度测量,并进行描述性统计学分析。结果四川汉族青少年人群面部10个标志点的中线软组织平均厚度,在青少年阶段大多数测量标志点随年龄增长而增厚;男女性面部中线软组织厚度统计学分析存在性别差异(P<0.05),在15岁之后差异增大,且LLI点显著差异性在9～20岁之间均存在(P<0.01)。结论四川汉族青少年面部中线软组织厚度有随年龄增长而增厚的趋势,男女面部软组织厚度存在性别差异。     

In vivo facial tissue depth measurements for white British children

This paper reports the results of a study of facial tissue depth measurement in White British children of both sexes, aged between 11 and 18 years. The purpose of this research was to increase the information available upon tissue depth data for children, primarily for use in forensic facial reconstruction. Facial tissue depths were measured at 21 anatomical points using ultrasonic echo-location. The mid-philtral, upper lip border and lower lip border points showed consistently larger tissue depths in the males than the females, and the zygomatic attachment showed consistently larger tissue depths in the females than the males. The males showed a general increase in tissue depth with an increase in age at all the mid-line facial points and the cheek points. The females showed increased tissue depth with age at all the points except the infra-orbital, lateral orbital, mid-zygomatic arch and mid-mandibular points. A table of mean tissue depths was developed for males and females divided into two-yearly age groups.     

Anthropological facial ‘reconstruction’ – recognizing the fallacies, ‘unembracing’ the errors, and realizing method limits

Despite being practiced for over the last 200 years, facial approximation methods remain in their infancy as the soft tissue prediction methods employed have not been tested and justified. Scientific testing is the only way forward and much of it is needed. The lack of systematic scientific tests in the past has enabled many misleading notions to become established. Many of these notions appear to have arisen and been sustained as a result of practitioner biases--this is clearly evident even in the name commonly used to describe the method of building faces from skulls, for "facial reconstruction" implies everything the method is not, e.g., technical/scientific, exact, and credible. Although facial approximation methods are useful for forensic investigation (even if they do not generate identifications through true positive recognitions of the faces), the public should beware of the marketing and political ploys employed within the profession. These ploys give rise to some impressive, but unjustifiable claims--but do not just take my word for it; evaluate the evidence for yourself with disregard to the indoctrination waged by the facial "reconstruction" field in general, including that promoted by what I have had to say here. Use your own reason and intellect and see which conclusions you reach.     

The mechanism of facial injury

Medicolegal experts are often asked to explain how, why and when facial injuries occurred. This can only be done satisfactorily if they are considered carefully and if all of the associated features are taken into account. One aspect of the topic which has received scant attention in medical and dental texts is Biodynamics, a brief analysis of the principal features of which is reproduced in this paper.     

Peculiarities of destruction in the facial area of the skull

Injuries observed in the facial skull area (FSA) in trauma made by hard blunt objects are registered within the forensic medical examinations of cadavers by far more rare than they are actually encountered in life. At the same time, a statement made to the effect that it was FSA that was affected in injuries of the cerebral skull area (CSA) is of an important forensic medical value. According to our research, the "strength beams" present in FSA and CSA are ovals and semi-ovals positioned above one another in 3 layers (top, medium and low ones). The anterior sections of all layers of FSA "strength beams" and of adjoining CSA regions, i.e. the squama of frontal bone (low one third of it) as well as anterior and middle cranial fossas, are a single deformative strength system. Specific features of each impact-zone region affect greatly a character of injuries in FSA at traumas in the medium facial third. Bones in the anterior and middle cranial fossas are damaged, apart from cranial injuries, in certain variations of impacts to FSA.     

Photo identification: facial metrical and morphological features in South African males

Personal identification of individuals is very important in forensic sciences. Facial identification is becoming even more relevant with increasing crime rates, problems with access control and terrorist attacks. To make facial identification more accurate, an in depth knowledge of the common and rare facial characteristics seen in various populations is needed. This will be advantageous when comparing facial photographs. Currently very little data is available on the facial variation of South Africans. Therefore the aim of this study was to analyse the facial features of a group of South African Bantu-speaking men, to determine the common and rare facial features seen in the group. Facial photographs were taken for 200 volunteers from the Pretoria Police College, in the norma frontalis position. The subjects were between 20 and 40 years of age, with no facial deformities. Thirteen measurements were taken directly from the photographs and used in 12 indices. Eight morphological features were also analysed on each face. Each feature was divided into different categories, which described variants of that feature. The metrical and morphological data were then used to create various combinations of facial characteristics that described different regions of the face. The frequency of occurrence of these combinations was calculated for the study population. The most common features were oval or inverted trapezoid facial shapes, intermediate size noses with a down-turned septum tilt and intermediate size mouths with a flat V-shaped upper lip notch (cupid's bow). The eyes were mostly situated closely together. Some of the rare or absent features included round or square facial shapes and narrow noses with an upturned septum tilt. Matching these rare features on facial photographs will be useful during cases of disputed identification.     

Three-dimensional cranio-facial reconstruction in forensic identification: latest progress and new tendencies in the 21st century

Three-dimensional (3D) cranio-facial reconstruction can be useful in the identification of an unknown body. The progress in computer science and the improvement of medical imaging technologies during recent years had significant repercussions on this domain. New facial soft tissue depth data for children and adults have been obtained using ultrasound, CT-scans and radiographies. New guidelines for facial feature properties such as nose projection, eye protrusion or mouth width, have been suggested, but also older theories and "rules of thumbs" have been critically evaluated based on digital technology. New fast, flexible and objective 3D reconstruction computer programs are in full development. The research on craniofacial reconstruction since the beginning of the 21st century is presented, highlighting computer-aided 3D facial reconstruction. Employing the newer technologies and permanently evaluating and (re)questioning the obtained results will hopefully lead to more accurate reconstructions.