Carl N Stephan

The University of Queensland | UQ · School of Biomedical Sciences

Determining which bilateral bones belong to the same person based on shape and size similarity is called pair-matching and it is instrumental for sorting commingled skeletons. To date, pair-matching has popularly been accomplished by visual inspection and/or linear caliper measurements; however, attention is turning increasingly to computational an...

Objectives To review the recent facial soft tissue thickness literature (2018-22) to determine if authors are currently adhering to standardised cephalometric landmarks and nomenclature, thereby supporting best scientific practices. Materials and Methods Facial soft tissue thickness (FSTT) studies published between 2018 – 2022 were identified usin...

Craniofacial superimposition requires the photographic registration of a skull at transparency to a photograph of an antemortem (AM) face so that anatomical concordance between the two can be assessed. When the camera vantage point of the AM photograph is exactly replicated for skull photography, the superimposition is a relatively straightforward...

As focus distance (FD) sets perspective, it is an important consideration for the forensic analysis of faces in photographs, including those used for craniofacial superimposition. In the craniofacial superimposition domain, the PerspectiveX algorithm has been suggested for FD estimation. This algorithm uses a mean value of palpebral fissure length,...

Craniofacial superimposition concerns the photographic overlay of skulls and faces, for skeletal identification. As a phased method that depends on photographic optics first and anatomical comparisons second, superimposition is strongly underpinned by the physics of light travel through glass lenses. So that the downstream (and dependent) anatomica...

In this study, we explore how image resolution and tissue shielding can impact correct classification rates (CCRs) of infracranial radiographic comparisons undertaken using small field-of-view radiographs. Thirty-six identification arrays (using clavicles and seventh cervical vertebra) were constructed with each array comprised of five radiographs:...

Subject-to-camera distance (SCD) is widely acknowledged to be a critical variable in craniofacial superimposition, but in practice it has been notoriously difficult to estimate from facial photographs. The recently proposed PerspectiveX algorithm offers the first potential capability to objectively undertake this estimation using quantified data. I...

Radiographic comparison for identification is widely utilized. However, these methods are qualitative and subject to analyst ability to correctly read and interpret radiographs. With regards to infra‐cranial radiographs, few studies have been conducted to explore the role of practitioner expertize on correct classification rates (CCRs). Here, we un...

Past anatomical dissection practice has received recent attention in the humanities and social science literature, especially in a number of popular format books. In these works, past ethically dubious dissection practices (mostly from the 1700 to 1800s, though they had their origins much earlier on) are again revisited, including stealing the dead...

Facial soft tissue thicknesses (FSTT) have long formed a quantitative cornerstone of craniofacial identification methods. Measurement approaches could, however, be improved by standardization that enhances the utility/comparability of these FSTT data between studies and authors. This applies equally within the broad classes of measurement technique...

Facial soft tissue thicknesses (FSTT) form a key component of craniofacial identification methods, but as for any data, embedded measurement errors are highly pertinent. These in part dictate the effective resolution of the measurements. As herein reviewed, measurement methods are highly varied in FSTT studies and associated measurement errors have...

Sir, We are very pleased that our letter (1) has generated a dialogue on practices concerning skeleton extraction/acquisition. This is a very important topic and one to which the universally recognized human right to dignity and respect in death is indeed highly applicable (1). Notably, this topic has not received prior attention in the skeletal co...

Facial imaging is a term used to describe methods that use facial images to assist or facilitate human identification. This pertains to two craniofacial identification procedures that use skulls and faces—facial approximation and photographic superimposition—as well as face-only methods for age progression/regression, the construction of facial gra...

Sir, Collections of authentic human skeletons are found across the world and comprise a cornerstone resource of forensic anthropology. Yet no Code of Practice currently exists to provide guidance on the disclosure of skeletal acquisition and processing methods...current practices are, across the world, highly varied...The herein presented Code of P...

Background: The Extensor Pollicis Brevis (EPB) is an extrinsic thumb muscle whose main function is extension of the first metacarpophalangeal joint (MCPJ). It is subject to significant anatomical variation and may be absent, vestigial or have an anomalous distal attachment. Clinical examination of EPB is notoriously difficult and no reliable test h...

Current quantitative methods for estimating ancestry and sex from skulls typically require substantial manual data collection and specialized recording equipment, which can limit analysis to the laboratory. This limitation could be addressed by establishing a faster, more user-friendly, and automatic data protocol as investigated in the current stu...

Soft tissues of the human face hang from the skull under the downward vector of gravity. Subsequently, the fall of the tissues is not likely the same between supine, prone or upright positions with ramifications for soft tissue measurements such as average soft tissue thicknesses used in craniofacial identification. Here we use high-resolution Dime...

The popular and repeated calculation of facial soft tissue thickness in different samples by different practitioners makes the development of a free, standard, and open-source tool that calculates all necessary statistics in an automated fashion useful. This tool should enable data analysis for single or multiple studies in both independent study-s...

It has been speculated that craniometric dimensions can be used to improve estimations of facial soft tissue thickness (FSTT) in craniofacial identification. Subsequently, linear regression (LR) models have been published, but the practical utility of these models (lower errors than means) has never been tested/demonstrated. Using 71 living subject...

For measurements to be accurate and precise, measurement errors should be small. In the anthropometry and craniofacial identification literature, four methods are commonly used for assessing measurement error: Pearson's product moment correlation coefficient (r), intra-class correlation coefficients (ICC), statistical significance tests (often repo...

The numerical description of skeletal morphology enables forensic anthropologists to conduct objective, reproducible, and structured tests, with the added capability of verifying morphoscopic-based analyses. One technique that permits comprehensive quantification of outline shape is elliptical Fourier analysis. This curve fitting technique allows a...

Facial soft tissue thicknesses (FSTT) set important quantitative guides in craniofacial identification, but so far Australian FSTTs have only been published for supine cadavers. This study aimed to use B-mode ultrasound to measure FSTTs in living Australians (N=63 participants; n1=52 [x¯=21 years, s=2 years]; and n2=11 [x¯=54years, s=13years]) usin...

The tallied facial soft tissue thicknesses (or T-Tables) represent grand means of published facial soft tissue thickness sample means. These sample means have been drawn from across the full-breadth of the facial soft tissue thickness (FSTT) literature, including forensic science, anthropology and odontology. The report of new summary statistics fo...

Unknown-provenance osteology is the rule rather than the exception at most well-established university anatomy laboratories. This circumstance results from the difficulties associated with processing skeletons and consequent historical reliance on external skeleton supply - one common source is the Calcutta bone trade that operated at its peak from...

The overlay of a skull and a face image for identification purposes requires similar subject-to-camera distances (SCD) to be used at both photographic sessions so that differences in perspective do not compromise the anatomical comparisons. As the facial photograph is the reference standard, it is crucial to determine its SCD first and apply this v...

In 2014, a morphometric capability to search chest radiograph databases by quantified clavicle shape was published to assist skeletal identification. Here, we extend the validation tests conducted by increasing the search universe 18-fold, from 409 to 7361 individuals to determine whether there is any associated decrease in performance under these...

Graphic exemplars of cranial sex and ancestry are essential to forensic anthropology for standardizing casework, training analysts, and communicating group trends. To date, graphic exemplars have comprised hand-drawn sketches, or photographs of individual specimens, which risks bias/subjectivity. Here, we performed quantitative analysis of photogra...

The shorth and 75-shormax were recently posited as an improved alternative to the arithmetic mean for describing facial soft tissue thicknesses in craniofacial identification. The shorth better estimates the data peak, while the 75-shormax provides improved provisions for a long right tail. When first proposed, the 75-shormax was subjectively gauge...

Males are universally reported to possess larger facial soft-tissue thickness (FSTT) than females, however, this observation oversimplifies the raw data yielding an underpowered assessment of FSTT sex-patterning where: differences are small (η(2) < 5%) and inconsistent (females are routinely larger than males at the cheeks). Here we investigate bod...

Standardized terms and methods have long been recognized as crucial to reduce measurement error and increase reliability in anthropometry. The successful prior use of craniometric landmarks makes extrapolation of these landmarks to the soft tissue context, as analogs, intuitive for forensic craniofacial analyses and facial photogrammetry. However,...

This research examines the utility of patella outline shape for matching 3D scans of patellae to knee radiographs using elliptical Fourier analysis and subjective methods of human visual comparison of patellae across radiographs for identification purposes. Repeat radiographs were captured of cadaver's knees for visual comparison before patellae we...

The superimposition of a face photograph with that of a skull for identification purposes necessitates the use of comparable photographic parameters between the two image acquisition sessions, so that differences in optics and consequent recording of images does not thwart the morphological analysis. Widely divergent, but published, speculations ab...

Facial soft tissue depth (FSTD) studies employing clinical computed tomography (CT) data frequently rely on depth measurements from raw 2D orthoslices. However, the position of each patient's head was not standardized in this method, potentially decreasing measurement reliability and accuracy. This study measured FSTDs along the original orthoslice...

Facial soft tissue thicknesses (FSTTs) hold an important role in craniofacial identification, forming the underlying quantitative basis of craniofacial superimposition and facial approximation methods. It is, therefore, important that patterns in FSTTs be correctly described and interpreted. In prior FSTT literature, small statistically significant...

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 soft tissue thickness means have long been used as a proxy to estimate the soft tissue envelope, over the skull, in craniofacial identification. However, estimation errors of these statistics are not well understood, making casework selection of the best performing estimation models impossible and overarching method accuracies controversial....

Facial approximation is used to predict a face from a skull. The method helps draw public attention to cases involving skeletal remains and/or prompts recognition of the deceased individual when the predicted face is advertised in the media. Facial approximations may be conducted manually or using computers. The former approach is widely considered...

Change in perspective between antemortem and postmortem imaging sessions (radiograph to radiograph and surface scan to radiograph) may cause different 2D renderings of the same osseous element complicating comparisons for identification. In this study, clavicle shape changes due to radiographic positioning and 3D laser scanning were examined in 20...

By pooling independent study means (x¯), the T-Tables use the central limit theorem and law of large numbers to average out study-specific sampling bias and instrument errors and, in turn, triangulate upon human population means (μ). Since their first publication in 2008, new data from >2660 adults have been collected (c.30% of the original sample)...

This paper describes a computerized clavicle identification system primarily designed to resolve the identities of unaccounted-for U.S. soldiers who fought in the Korean War. Elliptical Fourier analysis is used to quantify the clavicle outline shape from skeletons and postero-anterior antemortem chest radiographs to rank individuals in terms of met...

Several methods that have customarily been used in craniofacial identification to describe facial soft tissue depths (FSTDs) implore improvement. They include the calculation of arithmetic means for skewed data, omission of concern for measurement uncertainty, oversight of effect size, and misuse of statistical significance tests (e.g., p-values fo...

  This study examined eight previously published ear prediction methods by Welcker, Gerasimov, Fedosyutkin and Nainys, and Broadbent and Mathews. Computed tomography scans of 78 living adults (n(1) ) did not support any of these previously published recommendations. Free earlobes were found to accompany protruding supramastoid crests (Pearson's χ² ...

Bone remodeling is a natural process that is potentially problematic for radiographic comparisons because it can occur after antemortem (AM) imaging, thus interfering with the comparability of AM and postmortem (PM) radiographs from the same individual. While the effects of age-related remodeling have been studied, limited attention has been given...

The identification of skeletons cannot always be achieved using DNA and/or dental records. This is especially true of remains thought to belong to US military personnel that were recovered from the Korean War. A solution to this problem may be found by matching ante-mortem and post-mortem radiographs since the Joint POW/MIA Accounting Command (JPAC...

  Gerasimov’s plastic facial reconstruction method is notoriously difficult to repeat from the published literature. Primarily, this is because of the method’s underlying qualitative basis but other factors contribute including: misreports in the secondary literature of Gerasimov’s method essence; a lack of published details concerning Gerasimov’s...

This study investigated the value of antemortem (AM) and postmortem (PM) radiographs of the claviculae and C3-T4 vertebrae to identify skeletons of missing U.S. soldiers from past military operations. In total, 12 field-recovered skeletons and AM chest radiographs of 1460 individuals were used. For each skeleton, examiners analyzed an array of AM c...

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 g...

The masseter muscle forms a cornerstone of anatomical facial reconstruction (FR) methods, yet it is only scantily described in the FR literature despite relatively intense research focus from other disciplines. This suggests that much more data exists for masseter prediction than that which is currently used in FR. This paper reviews the masseter m...

The construction of the facial muscles (particularly those of mastication) is generally thought to enhance the accuracy of facial approximation methods because they increase attention paid to face anatomy. However, the lack of consideration for non-muscular structures of the face when using these "anatomical" methods ironically forces one of the tw...

Recently a small sampled cadaver study (n = 4) suggested that the human eyeballs are placed closer to the orbital roof and lateral orbital wall as first reported in the anatomical literature many years previously. This contrasts with central positioning of the eyeball within the orbit as advocated by the facial approximation literature. Given the l...

Prior research indicates that while statistically significant differences exist between subcategories of the adult soft tissue depth data, magnitudes of difference are small and possess little practical meaning when measurement errors and variations between measurement methods are considered. These findings raise questions as to what variables may...

With the ever increasing production of average soft tissue depth studies, data are becoming increasingly complex, less standardized, and more unwieldy. So far, no overarching review has been attempted to determine: the validity of continued data collection; the usefulness of the existing data subcategorizations; or if a synthesis is possible to pro...

An understanding of the structural relationships between the soft tissue anatomy of the face and the hard tissue anatomy of the skull is significant for craniofacial identification methods employed in forensic anthropology and forensic dentistry. Typically, mouth characteristics have been predicted from the teeth but this proves problematic in eden...

An accurate understanding of the spatial relationships between the deep and superficial structures of the head is essential for anthropological methods concerned with the comparison of faces to skulls (superimposition) or the prediction of faces from them (facial approximation). However, differences of opinion exist concerning: (i) the position of...

The success of facial approximation is thought to depend, at least in part, upon the "accuracy" of the constructed face. However, methods of accuracy assessment are varied and this range in methods may be responsible for the disparate results reported in the literature. The aim of this study was to determine if the accuracy results of one facial ap...

In the English literature, facial approximation methods have been commonly classified into three types: "Russian,"American," or "Combination." These categorizations are based on the protocols used, for example, whether methods use average soft-tissue depths (American methods) or require face muscle construction (Russian methods). However, literatur...

In the past, the accuracy of facial approximations has been assessed by resemblance ratings (i.e., the comparison of a facial approximation directly to a target individual) and recognition tests (e.g., the comparison of a facial approximation to a photo array of faces including foils and a target individual). Recently, several research studies have...

Craniofacial identification methods heavily rely on the knowledge of average soft tissue depths. This study measured soft tissue thicknesses of an Australian cadaver sample (N = 33) using published needle puncture techniques at 13 anatomical locations. Data were compared and contrasted with other studies that used essentially identical samples and...

The skeletal remains of one individual found near Adelaide in 1994, although not known at the time, were the first evidence of what was to be a serial killing reported to have resulted in the highest casualty list to date in Australia (12 victims). Since the usual methods of identification could not be used or were unsuccessful on these remains, fa...

Eyeball protrusion is one characteristic that must be assessed/predicted in craniofacial identification methods of skull-face superimposition and facial approximation. Previously it has been suggested that average exophthalmometry values, as measured on living individuals, should be used. However, it is unknown if proptosis prediction can be improv...

Separation of male and female soft tissue depths into discrete groups for craniofacial identification implies that males and females differ enough from each other, with respect to this application, for this distinction to be useful. In this study, previously published soft tissue depth data were analyzed for sex separation. It was found that the va...

Attempts are frequently made in craniofacial identification (e.g., craniofacial superimposition and facial approximation) to relate the ana-tomy of dry skulls to the antemortem appearance of individuals. However, drying processes and environmental conditions may affect the morphology and dimensions of skulls relative to their living state. This may...

This article describes and tests a photography rig that has been built at the University of Melbourne, Australia, specifically for the purpose of taking rapid and highly standardized craniofacial photographs, in simultaneous views of front and profile. The rig uses a novel projected light range-finding system that has been designed for easy and acc...

Many prediction guidelines exist in facial approximation for determining the soft-tissue features of the face, and the reliability of each is generally unknown. This study examines four published and commonly used soft-tissue prediction guidelines for estimating nose projection, two of which also estimate the position of the pronasale. The methods...

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 b...

It has been suggested that inter-canine width plus 57% of the cumulative distance between the lateral aspect of the canines and the pupil centers can be used to estimate mouth width. Evidence also suggests that the distance between the medial irises approximates actual mouth width fairly well. However, these soft tissue prediction guidelines are li...

Facial approximation techniques rely on the prediction of soft tissues from the skull, yet few prediction methods have been scientifically evaluated, despite being frequently used in the past. This study tests several published and commonly used methods for determining mouth width from the skull. The methods tested are: 1) that mouth width is equal...

The face is the body part that epitomises a human person. The face is what is required for identification of individuals in passports, on driver’s licences and other documents. It can even be argued that the human face is a cultural construct that cannot be studied without taking into account cultural values (Berrios, 2002, this volume). And yet th...

It has been suggested in the literature that superciliare is located directly above the most lateral point of the iris and that this association may be of use in facial approximation. However, the relationship between the lateral iris and superciliare has not been tested and its accuracy remains unknown. This study aims to determine the accuracy of...

The projection of the cornea from the bony orbit has been determined, in facial approximation, by centrally locating the eyeball in the orbit and positioning the cornea so that its most anterior point falls in line with a tangent dropped from the mid-superior to the mid-inferior orbital rim. However, there appears to be no scientific evidence to ju...

Since forensic facial approximations are used to promote recognition of a deceased person, an accurate forensic facial approximation (FFA) should be easily recognized as the person to whom the skull belonged (target individual). However, the accuracy of FFAs has been previously assessed by the direct comparison of an FFA to the corresponding target...

It appears that limited natural selection is taking place in populations of developed countries, since most individuals survive and have the full opportunity to reproduce. This paper addresses contemporary natural selection in a developed country (Australia) using the biological state index. Although the general context of this paper focuses on Aus...

Methods of facial approximation have successfully aided the identification of deceased individuals. Successes may be due to either accurate facial approximation techniques or chance. This study aims to determine if any of 16 facial approximations, built using standard techniques, are sufficiently accurate to produce correct identifications of targe...