Cranio-facial reconstruction in forensic identification--historical development and a review of current practice

Methods of forensic facial reconstruction and human identification: historical background, significance, and limitations

Facial reconstruction is the most frequently used method for human identification in forensic examinations. It is a complex and time-consuming technique and an actively growing field with a wide array of applications. The methods of forensic facial reconstruction are helpful in those cases where other methods of identification are not applicable. Identification of the dead is always a challenging task for forensic teams in cases involving terrorists' attacks and mass disasters where the corpses are fragmented, decomposed, and skeletonized. In such cases, only the skeletal remains and few other clues are available to establish the identity of a person. The progress of facial reconstruction was initiated in the nineteenth century, reconstructing the facial profiles of some famous and rich people. Various novel techniques for facial reconstruction have been devised in the recent past. We conducted literature search, using databases PubMed, Scopus, Web of Science, and ScienceDirect for analyzing different methods developed and practiced till date for human facial reconstruction. We outline the brief history along with a discussion regarding the different methods of forensic facial reconstruction and their limitations. We also discuss future recommendations and preferences for further research in the field of forensic facial reconstruction and human identification.

The development and testing of Thai facial soft tissue thickness data in three-dimensional computerized forensic facial reconstruction

Forensic facial reconstruction is a useful tool to assist the public in recognizing human remains, leading to positive forensic investigation outcomes. To reproduce a virtual face, facial soft tissue thickness is one of the major guidelines to reach the accuracy and reliability for three-dimensional computerized facial reconstruction, a method that is making a significant contribution to improving forensic investigation and identification. This study aimed to develop a facial soft tissue thickness dataset for a Thai population, and test its reliability in the context of facial reconstruction. Three-dimensional facial reconstruction was conducted on four skulls (2 males and 2 females, with ages ranging between 51 to 60 years). Two main tools of three-dimensional computer animation and modeling software-Blender and Autodesk Maya-were used to rebuild the three-dimensional virtual face. The three-dimensional coordinate (x, y, z) cutaneous landmarks on the mesh templates were aligned homologous to the facial soft tissue thickness markers on the three-dimensional skull model. The final three-dimensional virtual face was compared to the target frontal photograph using face pool comparison. Four three-dimensional virtual faces were matched at low to moderate levels, ranging from 30% to 70% accuracy. These results demonstrate that the facial soft tissue thickness database of a Thai population applied in this study could be useful for three-dimensional computerized facial reconstruction purposes.

The revolutionary developmental biology of Wilhelm His, Sr

Swiss‐born embryologist Wilhelm His, Sr. (1831–1904) was the first scientist to study embryos using paraffin histology, serial sectioning and three‐dimensional modelling. With these techniques, His made many important discoveries in vertebrate embryology and developmental neurobiology, earning him two Nobel Prize nominations. He also developed several theories of mechanical and evolutionary developmental biology. His argued that adult form is determined by the differential growth of developmental primordia. Furthermore, he suggested that changes in the growth parameters of those primordia are responsible for generating new phenotypes during evolution. His developed these theories in his book ‘Our Bodily Form’ (Unsere Körperform). Here, we review His's work with special emphasis on its potential importance to the disciplines of evolutionary developmental biology (evo‐devo) and mechanobiology.

Digital 2D, 2.5D and 3D Methods for Adding Photo-Realistic Textures to 3D Facial Depictions of People from the Past

Facial reconstruction is a technique that can be used to estimate individual faces from human skulls. The presentation of 3D facial reconstructions as photo-realistic depictions of people from the past to public audiences varies widely due to differing methods, the artists' CGI skillset, and access to VFX software required to generate plausible faces.This chapter describes three digital methods for the addition of realistic textures to 3D facial reconstructions; a 2D photo-composite method, a 3D digital painting and rendering method, and a previously undescribed hybrid 2.5D method.These methods are compared and discussed in relation to artistic proficiency, morphological accuracy and practitioner bias.

Forensic Recreation and Visual Representation of Greek Orthodox Church Saint Eftychios of Crete

Facial reconstruction is employed in medical science and archaeology. Though quite popular as anthropological method, it has not so far been used in the orthodox ecclesiastical tradition. This work presents the facial reconstruction of St Eftychios of Crete, who lived between the ninth and tenth centuries. Computed tomography and reverse engineering methods were employed to complete the task. Reconstruction of the mandible and the missing left zygomatic arch was implemented following the Sassouni method. The American method was followed for the soft tissues, with clay deposition of appropriate thickness, on the surface of the skull model. The eyes, nose, and lips were added based on the dimensions of the underlying bone structures. Long hair and beard were added, according to the classic Byzantine tradition pattern of the time period. The final bust developed was then digitized, using a 3D non-contact laser scanner. The 3D geometry produced was employed to produce a mold with vacuum casting techniques. This mold provides the ability to produce copies of the bust, if needed. At the same time, a realistic 3D representation of the Saint's bust was developed, with the aid of special software, in order to compare the traditional forensic reconstruction to the pure digital one. This work is the first case of a Saint's facial reconstruction in the Orthodox Church. The facial reconstruction process, with all the limitations considered, offers the ability to present a realistic aspect of a Greek Orthodox Church Saint, in a form that is easily accessible. Both physical and digital facial reconstruction processes were based on scientific data, so they were as accurate as possible, considering that the mandible was missing in the skull. The facial reconstruction was entirely implemented in Greece creating the basis for similar work in the future. The final bust developed was donated to the Odigitria Monastery, to be exhibited to its visitors.

A detailed review of forensic facial reconstruction techniques

Facial reconstruction is an effective forensic technique that can help recreate a victim's facial appearance from the skull. It is typically used to assist law enforcement agencies to identify missing deceased persons. Reconstruction techniques are usually based on the relationship between the underlying hard tissues, such as bone structure, and soft tissues such as the facial muscles and facial features. Facial reconstruction can be a feasible alternative to identify the remains from a decomposed, mutilated, or skeletonised corpse. It is important to remember that although the outcomes are empirical in nature, the technique has been applied widely in many situations. Recent advancements in technology and computer-based techniques have increased the accuracy and validity of this forensic discipline. We consider the most commonly used facial reconstruction techniques in this paper, with a detailed description of manual 3D techniques.

The Relationship Between Hard Tissue and Soft Tissue Dimensions of the Nose in Children: A 3D Cone Beam Computed Tomography Study

This study using three-dimensional cone beam computed tomography (CBCT) images of children determined relationships between nasal skeletal and soft tissue measurements and assessed the association with sex, age, and skeletal maturation stage. Following reliability studies, skeletal and soft tissue parameters were measured on coded CBCTs of 73 children (28M:45F;6-13 yoa). Pearson and Mantel correlations were used to analyze associations between skeletal and soft tissues. Partial Mantel correlations were used to study the associations between skeletal and soft tissue, adjusting for sex, age, and skeletal maturation. Linear regression analyses were used to predict soft tissues sizes. Logistic regression was used to study the relationships between soft and skeletal tissue symmetry. Except for nasal aperture width and interalar width, skeletal landmarks best predicted corresponding soft tissue landmarks. Significant positive associations existed between skeletal and soft tissues after adjusting for sex, skeletal maturation, and age. Children's nasal skeletal tissues predicted nasal soft tissue reasonably well.

Variations in the Facial Dimensions and Face Types among the Students of A Medical College

INTRODUCTION

Facial dimensions and the face types are the most variable factors in human community. These dimensions have practical implications for the anthropologist, forensic experts, anatomists and surgeons. The present study is aimed to determine the facial dimensions and face types among the medical and nursing students.

METHODS

A cross-sectional study was done among medical and nursing students of Devdaha Medical College and Devdaha College of Science and Technology from January 2017 to February 2018. There were 155 students of which 72 were males and 83 females. Facial height and width were measured and facial index was calculated. The collected data was entered and analyzed in SPSS 21 and differences in measurements among males and females were calculated.

RESULTS

The mean facial height among the total population was 10.83 ± 0.74 cm and facial width was 12.39 ± 0.67 cm with the mean facial index of 87.44 ± 4.82. The most prevalent was the mesoprosopic face (n= 59, 38.06%) followed by leptoprosopic (n=43, 27.74%). The least prevalent face type was hyperleptoprosopic (n= 7, 4.52%) which was observed only in male individuals.

CONCLUSIONS

The present study depicts higher values of facial height, width and facial indexfor males when compared to the females. The present finding is based upon the indices and classification obtained from developed nation. Further studies with local data would help develop indices and classification for Nepalese population.

A facial reconstruction and identification technique for seriously devastating head wounds

Many authors have focused on facial identification techniques, and facial reconstructions for cases when skulls have been found are especially well known. However, a standardized facial identification technique for an unknown body with seriously devastating head injuries has not yet been developed. A reconstruction and identification technique was used in 7 cases of accidents involving trains striking pedestrians. This identification technique is based on the removal of skull bone fragments, subsequent fixation of soft tissue onto a universal commercial polystyrene head model, precise suture of dermatomuscular flaps, and definitive adjustment using cosmetic treatments. After reconstruction, identifying marks such as scars, eyebrows, facial lines, facial hair and partly hairstyle become evident. It is then possible to present a modified picture of the reconstructed face to relatives. After comparing the results with photos of the person before death, this technique has proven to be very useful for identifying unknown bodies when other identification techniques are not available. This technique is useful for its being rather quick and especially for its results.

In vivo facial tissue depth study of Chinese-American adults in New York City

This study examines facial tissue depth in adult Chinese-Americans. Using ultrasound, measurements were taken at 19 landmarks across the faces of 101 individuals aged from 18 to 87 years. Summary statistics are reported for a sample of 67 individuals of normal weight (as determined by a body mass index [BMI] of 19-25). Statistical analyses were used to assess relationships between tissue thickness, age, and BMI. Results indicate that no significant relationship exists between tissue thickness and age for males, and for only 3/19 points in females. Also, only four points showed significant relationships between tissue thickness and sex. However, significant relationships exist between BMI and tissue thickness at multiple points for both males and females. Compared to other American and Asian populations in the literature, Chinese-Americans generally had thinner facial tissue; though, this difference was not assessed statistically. Finally, data generated in this study will add to the body of knowledge concerning facial tissue depth variation in modern humans.

Assessment of the accuracy of three-dimensional manual craniofacial reconstruction: a series of 25 controlled cases

The aim of this work was to estimate the accuracy of craniofacial reconstruction (CFR), from a series of 25 controlled cases. Three protocols of blind CFRs (exhibiting an increasing complexity from A to C) were assessed in this paper, allowing comparison of the CFR with the actual face of the deceased. The whole results showed that an excellent, or good, to middle resemblance (between the blind CFR and the actual face of the subject) was reached in 9 out of 25 cases, but the success gradually increased from the A to the C protocol of CFR, reaching six cases out of eight in the latter. Statistical comparison of measurements (between the blind CFR and the actual face) was also achieved, revealing that some anthropological distances were constantly underestimated or overestimated. This experiment shows that a thorough anthropological, odontological, and X-ray analysis is indispensable before performing a CFR, and these encouraging results justify further efforts of research in this field.

A New Experimental Approach to Computer-Aided Face/Skull Identification in Forensic Anthropology

The present study introduces a new approach to computer-assisted face/skull matching used for personal identification purposes in forensic anthropology. In this experiment, the authors formulated an algorithm able to identify the face of a person suspected to have disappeared, by comparing the respective person's facial image with the skull radiograph. A total of 14 subjects were selected for the study, from which a facial photograph and skull radiograph were taken and ultimately compiled into a database, saved to the hard drive of a computer. The photographs of the faces and corresponding skull radiographs were then drafted using common photographic software, taking caution not to alter the informational content of the images. Once computer generated, the facial images and menu were displayed on a color monitor. In the first phase, a few anatomic points of each photograph were selected and marked with a cross to facilitate and more accurately match the face with its corresponding skull. In the second phase, the above mentioned cross grid was superimposed on the radiographic image of the skull and brought to scale. In the third phase, the crosses were transferred to the cranial points of the radiograph. In the fourth phase, the algorithm calculated the distance of each transferred cross and the corresponding average. The smaller the mean value, the greater the index of similarity between the face and skull.A total of 196 cross-comparisons were conducted, with positive identification resulting in each case. Hence, the algorithm matched a facial photograph to the correct skull in 100% of the cases.

Unidentified bodies/skulls found in Danish waters in the period 1992-1996

In the period 1992-1996 a total of 89 unidentified bodies/skulls found in Danish waters were investigated at the three University Institutes of Forensic Medicine in Denmark. Males constituted 79% of the total material. Open water was the finding place in half the cases, about one-fourth was found on shore and another fourth in a harbor basin. Totally 73 bodies and one skull were identified. Danes constituted 57% of the material. Almost all non-Danes originated from countries with borders to the waters surrounding Denmark. The cause of death was in 71% stated as presumably/possibly drowning, in 5% as severe lesions (precipitation) and in 25% it could not be solved. The manner of death was in non-Danes most often stated as an accident (56%), and according to this the finding place in non-Danes most frequently was the open water (66%). In Danes suicide predominated (71%) and the finding place in Danes was almost equally distributed among open water, shores and harbors, respectively. Among the totally 74 identified cases, 83% of the total material, an initial suggestion of the identity based on effects found on the body was possible in 43 cases (58%). The final identification was performed by means of forensic dental examination in total 58 cases (78%), in Danes in 93% and in non-Danes in 59%. In the remaining 16 cases one or more of the following contributed to the final identification: information about dental condition, clothing, personal papers, X-ray photos, jewelry, tattoos/scars and fingerprints. The importance of a close collaboration between the police, the forensic pathologist and the forensic dental expert in order to reach a fair number of positive identifications is emphasized.