Facial Approximation Research Articles

Soft tissue thickness values for black and coloured South African children aged 6–13 years

In children, craniofacial changes due to facial growth complicate facial approximations and require specific knowledge of soft tissue thicknesses (STT). The lack of South African juvenile STT standards of particular age groups, sex and ancestry is problematic. According to forensic artists in the South African Police Service the use of African–American values to reconstruct faces of Black South African children yields poor results. In order to perform a facial approximation that presents a true reflection of the child in question, information regarding differences in facial soft tissue at different ages, sexes and ancestry groups is needed. The aims of this study were to provide data on STT of South African Black and Coloured children and to assess differences in STT with respect to age, sex and ancestry. STT was measured using cephalograms of South African children (n=388), aged 6–13 years. After digitizing the images, STT measurements were taken at ten mid-facial landmarks from each image using the iTEM measuring program. STT comparisons between groups per age, sex and ancestry were statistically analyzed. The results showed that STT differences at lower face landmarks are more pronounced in age groups per ancestry as opposed to differences per age and sex. Generally, an increase in STT was seen between 6–10 year old groups and 11–13 year old groups, regardless of ancestry and sex, at the midphiltrum, labiale inferius, pogonion, and beneath chin landmarks. This research created a reference dataset for STT of South African children of Black and Coloured ancestry per age and sex that will be useful for facial reconstruction/approximation of juvenile remains.

Facial approximation-from facial reconstruction synonym to face prediction paradigm.

Facial approximation was first proposed as a synonym for facial reconstruction in 1987 due to dissatisfaction with the connotations the latter label held. Since its debut, facial approximation's identity has morphed as anomalies in face prediction have accumulated. Now underpinned by differences in what problems are thought to count as legitimate, facial approximation can no longer be considered a synonym for, or subclass of, facial reconstruction. Instead, two competing paradigms of face prediction have emerged, namely: facial approximation and facial reconstruction. This paper shines a Kuhnian lens across the discipline of face prediction to comprehensively review these developments and outlines the distinguishing features between the two paradigms.

A hyper-realistic method for facial approximation: the case of the Italian humanist Angelo Poliziano.

Frequently, identification of individuals is problematical due to the level of associated decomposition and even more when the skeletal remains are incomplete or fragmented. The identikit, which includes a sketch or a facial reconstruction, could assist investigators with determining the identity of the decedent. Similarly, in archeology and physical anthropology it gives a realistic appearance to a historical character known only through iconography. We examined the skull of Angelo Poliziano, an Italian humanist of the 15(th) century. Previously, his facial approximation was completed in clay according to the Manchester protocol and then a duplication was prepared in ultra-realistic materials. This technique returns a long lasting 3D model of the individual and provides the perception to be in front of a real person and, although expensive, applied in forensic context could it improve the recognition of the individual.

Complex Analysis of 700-Year-Old Skeletal Remains found in an Unusual Grave–Case Report

Aim: The present study was designed to analyze the 700-year-old human remains from an unusual grave using a combined approach that consisted of anthropological, archaeogenetic, genealogical, mass spectrometry, 3-dimensional (3D) modeling and facial reconstruction methods to confirm or reject several hypotheses about the skeletal remains. Methods: DNA was extracted from the skeleton and amplified using autosomal and Y-chromosome human identification short tandem repeat (STR) kits that were designed for forensic use, and sequence data were obtained from hyper variable region I (HVRI) mtDNA sequencing. Elemental mapping and quantification of investigated elements were performed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The Computed Tomography (CT) images of the skull were created in a transversal plane, and the scans were used to create 3D geometric models of the skull. A plastic physical model (a cast) of the skull was produced by rapid prototyping technology, and the model was used for sculptural facial approximation of the studied individual. Results: The Y-chromosome haplogroup of the sample was determined to be E1b1b, and the assigned mtDNA haplogroup was H. LA-ICP-MS and geochemical analysis revealed that the individual consumed plants and meats, except pork. Anthropological examination estimated the age of the individual to be between 45-55 years, and we did not find any traces of disablement or physical anomalies. Interestingly, we were able to produce a facial reconstruction according to the skull. Conclusion: Applying a multidisciplinary approach to the examination of the 14th century material enabled us to retrieve new types of information that helped us to interpret the excavated skeletal remains.

Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

Assessment of presentation methods for ReFace computerized facial approximations

Facial approximations (whether clay sculptures, sketches, or computer-generated) can be presented to the public in a variety of layouts, but there are currently no clear indicators as to what style of presentation is most effective at eliciting recognition. The primary purpose of this study is to determine which of five presentation methods produces the most favorable recognition results. A secondary goal of the research is to evaluate a new method for assessing the accuracy of facial approximations. Previous studies have evaluated facial approximation effectiveness using standards similar to studies of eyewitness identification in which a single, definitive choice must be made by the research participant. These criteria seem inappropriate given that facial approximation is strictly an investigative tool to help narrow the search for potential matching candidates in the process of identification. Results from the study showed a higher performance for methods utilizing more than one image of the approximation, but which specific method performed best varied among approximation subjects. Also, results for all five presentation methods showed that, when given the opportunity to select more than one approximation, participants were consistently better at identifying the correct approximation as one of a few possible matches to the missing person than they were at singling out the correct approximation. This suggests that facial approximations have perhaps been undervalued as investigative tools in previous research.

GEOREFERENCING A COLD CASE VICTIM WITH LEAD, STRONTIUM, CARBON, AND OXYGEN ISOTOPES

Two men walking across a bridge along highway I‐75 found a young woman's body floating in the water below. This 1971 case has since become known as the “Little Miss Panasofkee” case. It is still an open homicide, for which neither the victim nor the perpetrator have been identified. Throughout the United States, thousands of similar cases remain open. The medicolegal communities work on these cases, as the years pass, applying new scientific methods and following new leads as they can be developed. As the years pass, the priorities of the investigations often shift. In any homicide investigation the goal is to solve the murder and bring the perpetrator to justice. While this is still true for long‐term open or cold cases, the needs of families to know the truth, find and bury remains, and find closure outside of criminal trials become increasingly important. In the case study presented here, we reanalyzed the biological profile of the decedent, created a new facial approximation and imaging for visualization of personal evidence, and analyzed samples of hair, bone, and enamel for Sr, Pb, C, N, and O isotopes to decipher a geographical place of origin for the decedent. Hair data show a shift from lighter to heavier C isotopic values indicating a diet change from more grain‐based (hair tip) to more corn‐based (hair root) diet. Oxygen isotopes in teeth show relatively heavy isotopic values suggesting southern geographical origin near a major water basin. Lead isotopic data for teeth and bone samples show relatively low‐radiogenic values suggesting that the victim was born and raised in Europe. There is shift to low 87Sr/86Sr from first to third molar and bone indicating possible migration and dietary change. Taken together, the radiogenic and stable isotope data indicate that the decedent was foreign born. The shift in the hair C isotopes suggests that the victim arrived in Florida/United States between 2 and 12 months before she was murdered. The Pb isotope data suggest European origin. Considering all of the chemical data, including Pb concentrations and Pb, Sr, O, and C isotope analyses on teeth, rib, and hair samples, we can suggest that the victim was most likely a foreigner from southeastern Europe, possibly Greece. The methods used here and the impact of these methods for developing new leads for investigators decades later are discussed and provide new avenues of investigation for other unsolved cases.

Preliminary assessment of facial soft tissue thickness utilizing three-dimensional computed tomography models of living individuals

Facial approximation is the technique of developing a representation of the face from the skull of an unknown individual. Facial approximation relies heavily on average craniofacial soft tissue depths. For more than a century, researchers have employed a broad array of tissue depth collection methodologies, a practice which has resulted in a lack of standardization in craniofacial soft tissue depth research. To combat such methodological inconsistencies, Stephan and Simpson 2008 [15] examined and synthesized a large number of previously published soft tissue depth studies. Their comprehensive meta-analysis produced a pooled dataset of averaged tissue depths and a simplified methodology, which the researchers suggest be utilized as a minimum standard protocol for future craniofacial soft tissue depth research. The authors of the present paper collected craniofacial soft tissue depths using three-dimensional models generated from computed tomography scans of living males and females of four self-identified ancestry groups from the United States ranging in age from 18 to 62 years. This paper assesses the differences between: (i) the pooled mean tissue depth values from the sample utilized in this paper and those published by Stephan 2012 [21] and (ii) the mean tissue depth values of two demographically similar subsets of the sample utilized in this paper and those published by Rhine and Moore 1984 [16]. Statistical test results indicate that the tissue depths collected from the sample evaluated in this paper are significantly and consistently larger than those published by Stephan 2012 [21]. Although a lack of published variance data by Rhine and Moore 1984 [16] precluded a direct statistical assessment, a substantive difference was also concluded. Further, the dataset presented in this study is representative of modern American adults and is, therefore, appropriate for use in constructing contemporary facial approximations.

Forensic Facial Reconstruction: Review and Analysis of Scientific Research in Brazil

Forensic Facial Reconstruction (FFR) refers to any process that aims to recover the morphology of a face at the moment before death, from the observation of a skull. It’s a recognition method that allows direct investigations for primary methods of human identification. The literature on this topic is very extensive, however, there are only few national studies, even in Forensic Dentistry. The present study aimed to review and to analyze the Brazilian research publications about FFR. On April 13, a search for references was carried on Bibliografia Brasileira de Odontologia (BBO) and Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) electronic full-text databases with the terms “forensic facial reconstruction”, “forensic facial reconstitution” and “forensic facial approximation”. A total of 10 national references was found, between 2000 and 2012: 2 articles, 3 dissertations and 5 theses. Most of the references belong to the field of dentistry and the topic that was most studied is facial soft tissue thickness of Brazilian subjects, totaling 30% of the publications. About 50% of the studies have been made since 2010, which shows that the national studies are recent. We conclude that the Brazilian literature on FFR has been growing, but there is still a lack of research. The preparation of theses and dissertations is valuable for the development of Forensic Sciences and Forensic Dentistry.

Preliminary performance assessment of computer automated facial approximations using computed tomography scans of living individuals

ReFace (Reality Enhancement Facial Approximation by Computational Estimation) is a computer-automated facial approximation application jointly developed by the Federal Bureau of Investigation and GE Global Research. The application derives a statistically based approximation of a face from a unidentified skull using a dataset of ∼400 human head computer tomography (CT) scans of living adult American individuals from four ancestry groups: African, Asian, European and Hispanic (self-identified). To date only one unpublished subjective recognition study has been conducted using ReFace approximations. It indicated that approximations produced by ReFace were recognized above chance rates (10%). This preliminary study assesses: (i) the recognizability of five ReFace approximations; (ii) the recognizability of CT-derived skin surface replicas of the same individuals whose skulls were used to create the ReFace approximations; and (iii) the relationship between recognition performance and resemblance ratings of target individuals. All five skin surface replicas were recognized at rates statistically significant above chance (22–50%). Four of five ReFace approximations were recognized above chance (5–18%), although with statistical significance only at the higher rate. Such results suggest reconsideration of the usefulness of the type of output format utilized in this study, particularly in regard to facial approximations employed as a means of identifying unknown individuals.

Faces of Homo floresiensis (LB1)

Since being excavated in 2003, the skull of LB1 (the holotype of Homo floresiensis) has been given many faces, though the details regarding how each was accomplished are typically few. Here we detail our application of known, and verified, relationships between the skull and soft tissues of anatomically modern humans to produce an evidence-based facial approximation of LB1. We then compare our results to nine pre-existing LB1 faces using geometric morphometrics. These analyses suggest our facial approximation differs in proportional facial width, upper lip height and nasal morphology. Some of these differences are likely due to a different interpretation of taphonomic and excavation damage, application of different 'forensic' methods and/or an idiosyncratic incorporation of aspects of non-human primate morphology. Other differences, and in particular upper lip height, are less justifiable in relation to the skeletal evidence.

Facial soft tissue thickness in the Brazilian population: New reference data and anatomical landmarks

Facial soft tissue thickness measurement can be useful among several medico-legal techniques that aim to establish the identity of skeletal remains. This study examined the soft tissue thickness that covered the faces of autopsied cadavers sent to the Medico-Legal Institute of Guarulhos from September 2010 to September 2011. Forty-nine anatomical facial landmarks were measured in cadavers less than 24h after death; these data were analysed using two-tailed t-tests. This project was approved by an ethics committee. One hundred cadavers were studied (74 males and 26 females). A majority of these individuals had died between 41 and 60 years old. Of the 49 anatomical landmarks, only five differed between the sexes (i.e., p-value less than 0.05): upper lip margin (p=0.006), superior labial sulcus (p=0.006), stomion (p=0.001), right lateral orbit (p=0.008), and left cheilion (p=0.009). The inclusion of additional anatomical landmarks allowed us to establish more precise facial thickness parameters that have the potential to be applied to cadaver facial approximations in Brazil; furthermore, some anatomic landmarks presented a higher discriminant power with regard to sex.

Facial soft tissue depths in French adults: Variability, specificity and estimation

Facial soft tissue depths (FSTD) are used in facial approximation to render the shape of the face, and are traditionally published specifically to population, corpulence, and sex amongst other factors. This paper investigates the variability of FSTD collected at 37 landmarks on 500 CT (computed tomography) scans of French living individuals. The specificity of the sample is evaluated by comparing values with six published datasets of various populations and recording techniques. Apart from a significant influence of the corpulence, FSTD show negligible variations with age and sex. The differences between the French sample and other datasets contradict the hypothesis of major influence of population, and underline sample specificity linked with technique and methodology of data measurement. Regression equations were computed to estimate FSTD using age, sex, facial build, and craniometrics, leading to more accurate results if such factors are known. Nevertheless, application of the pooled T-table (Tallied-Facial-Soft-Tissue-Depth-Data) has been validated according to the French sample.

Who is this person? A comparison study of current three-dimensional facial approximation methods

Facial approximation is a common tool utilised in forensic human identification. Three-dimensional (3D) imaging technologies allow researchers to go beyond traditional clay models to now create virtual computed models of anatomical structures. The goal of this study was to compare the accuracy of available methods of facial approximation ranging from clay modelling to advanced computer facial approximation techniques. Two computerised reconstructions (FaceIT and FBI's ReFace) and two manual reconstructions (completed by FBI's Neville and Faraut) were completed using a skull from a known individual.A living individual's computed tomography (CT) scan was used to create a virtual 3D model of the skull and soft tissue of the face. The virtual skull models were provided to the computer-based approximation specialists. A rapid prototype of the skull was printed and provided to the practitioners who needed physical specimens.The results from all of the methods (clay and virtual) were compared visually to each other and collectively to the actual features of the living individual to compare the results of each. A quantitative study was also conducted to establish the accuracy of each method and the regions of the face that need the most improvement for all of the specialists.This project demonstrates the wide range of variation between commonly used facial identification methods. The benefit of this study was having a living individual to test the strengths and weaknesses of each method while also providing future areas of focus for soft tissue depth data studies.

Accuracy and reliability of soft tissue depth measurements from CT for forensic facial reconstruction

Introduction Facial approximation (FA) is used when other methods of forensic identification, such as DNA, are not available or applicable. FA, in the clay methods and virtual methods, all rely on populational soft tissue (ST) depths from limited data sets. Much of the known facial indices originate from cadaver ST studies. This study, using three-dimensional (3D) computer modeling, tested the accuracy and reliability of cadaveric facial studies as they apply to forensic cases. Methods A series of embalmed cadaveric heads were scanned with computed tomography (CT). The head's bone and ST were 3D modeled using Mimics 15.0. Measurements of ST landmarks were collected from the 3D models. After scanning, ST measurements were taken manually from the cadavers. Photographs were taken to document the tissue depth markers' location. These physical measurements were compared to the virtual data. A series of clinical head scans of living individuals were collected and modeled for the comparison of scanning cadaveric and clinical tissue. Results ST measurements demonstrate that cadavers are often distorted in the facial region. The distortions from embalming skew ST measurements. The landmarks used in ST data collection are chiefly defined by boney features and not the skin surface. Discussion It is a concern as these features are not visible during data collection, the researcher must approximate where they believe the feature to be. The utilization of CT and 3D reconstruction allows for a more reliable location for ST measurement. Due to cadaver limitations, the use of clinical facial CT data proved to be the ideal data set for modern living individuals. Conclusion If FA is to remain a tool in human identification then more clinically relevant data is needed. With advances in medical imaging, the embalmed cadaver, unfortunately, is no longer the optimal model for facial reconstruction studies.

Facial soft tissue thicknesses of the mid-face for Slovak population

Forensic facial approximation is used as a tool for recreating the antemortem appearance of unknown dead and thus facilitates their identification. Several approaches to facial approximation are based on data on facial soft tissue thicknesses (FSTTs). The availability of sex-, age- and population-specific data contributes to the accuracy of the resulting facial approximation model. In this paper, first data set on FSTTs for a Central European population are presented. Soft tissue thicknesses of the mid-face were measured on 160 head CT-scans of 80 males and 80 females aged from 18 to 87 years. These CT-scans were made available after being a part of the diagnostic procedure concerning the paranasal sinuses of the patients. Basic descriptive statistics (i.e. mean, SD, median, range) for the FSTTs at 14 facial landmarks is reported separately by sex and age. Such information allows the forensic artist to choose the most suitable values for the FSTT considering the previous physiological and osteological analysis of the human remains.

Anatomical Placement of the Human Eyeball in the Orbit—Validation Using CT Scans of Living Adults and Prediction for Facial Approximation*

Accuracy of forensic facial approximation and superimposition techniques relies on the knowledge of anatomical correlations between soft and hard tissues. Recent studies by Stephan and collaborators (6,8,10) reviewed traditional guidelines leading to a wrong placement of the eyeball in the orbit. As those statements are based on a small cadaver sample, we propose a validation of these findings on a large database (n = 375) of living people. Computed tomography scans of known age and sex subjects were used to collect landmarks on three-dimensional surfaces and DICOM with TIVMI. Results confirmed a more superior and lateral position of the eyeball relatively to the orbital rims. Orbital height and breadth were used to compute regression formulae and proportional placement using percentages to find the most probable position of the eyeball in the orbit. A size-related sexual dimorphism was present but did not impact on the prediction accuracy.

A simple method of nose tip shape validation for facial approximation

Despite numerous papers relating to the prediction of nose projection for the purposes of facial approximation, there is little guidance for nose tip shape that has been evaluated on a known data set. This study presents a novel, simple technique for validation of the reconstructed nose tip shape based on methods used in actual approximation practice. The data set was comprised of 25 full-head computed tomography (CT) patient scans. In 22 of the 25 patients across all age and sex groups, when the head is tilted so that soft tissue pronasale is superimposed on hard tissue rhinion, the curvature of the nose tip was found to mimic the curvature of the superior portion of the nasal aperture. This occurs when the head is tilted dorsally by approximately 60° (55.87±5.91). Individuals with snub noses presented a much wider tip curvature. The method was highly repeatable and was evaluated through inter- and intra-observer studies (error=3.15%).

Approximating the Face of ‘Aunty’: A Question of Likeness

This paper describes two approaches to the facial approximation of three individuals from the Wairau Bar burial site (New Zealand). Two individuals were approximated working in direct reference to the remains and incorporated manual drafting. The third individual, ‘Aunty’ (the respectful title given by the iwi Rangitane elders) was approximated from CT scans and using computer graphics. The computer graphic approach enabled a greater level of precision in the application of the research and recommendations that inform a facial approximation, and facilitated collaboration with appropriate expertise. The computer-graphic approach, however, also resulted in a more photographic facial appearance, which can imply a greater level of knowledge about hard/soft tissue relationships than is currently available.

The reproducibility of facial approximation accuracy results generated from photo-spread tests

The accuracies of facial approximations have been measured by determining the frequency that examiners recognize correctly matching faces from photo-spreads under blind conditions. However, the reliability of these studies is unknown and warrants investigation since photo-spread results are based on subjective judgements of typically small single groups of examiners (<150 individuals). Moreover, statistical significance tests hold limited value for gauging reliability since these probabilities are only applicable to exactly matched study samples. To redress this issue, this study measured the repeatability of photo-spread results using three previously published facial approximations, the same photo-spread from the original study, and four independent groups of examiners (the original study group (trial 1); and three retest groups: trial 2 = c. 40 individuals; trial 3 = c. 75 individuals; and trial 4 = c. 115 individuals). Across all three facial approximations, differences in recognition rates varied from 0% to 31% between independent samples of examiners. For the nine faces that commonly received high recognition scores, the largest mean difference was 18%. This indicates that when a photo-spread size of 10 faces is used, the results generated from a sample of <115 examiners should be considered approximate, and that any differences in the recognition rates that do not exceed 18% should be considered to be negligible.