- Carl is a Senior Lecturer and Heads the Laboratory for Human Craniofacial and Skeletal Identification (HuCS-ID Lab) @... moreCarl is a Senior Lecturer and Heads the Laboratory for Human Craniofacial and Skeletal Identification (HuCS-ID Lab) @ UQ. He is founding Curator of the SBMS Skeletal Collection (1st collection of modern-day indefinite body donors in Australia) and teaches into a variety of human gross anatomy courses. Carl formerly worked at the JPAC Central Identification Laboratory as an ORISE Research Fellow and Anthropologist. He currently serves on the Editorial Board of the Journal of Forensic Sciences.edit
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... more
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 were extracted and skeletonized for quantitative comparisons. Quantitative methods provided significant narrowing down of the candidate pool to just a few potential matches (<5% of original sample), while the human analysts showed high capacity for correctly matching radiographs, irrespective of educational level (positive predictive value = 99.8%). The successful computerized matching based on a single quantified patella trait (outline shape) helps explain the potency achieved by subjective visual examination. This work adds to a growing body of studies demonstrating the value of single isolated infracranial bones for human identification via radiographic comparison.
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Abstract: 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... more
Abstract: 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 eyeball in planes other than the anteroposterior plane and (ii) the canthi positions relative to the bony orbital margins. This study attempts to clarify the above relationships by dissection of a small sample of adult human cadavers (N = 4, mean age = 83 years, s = 12 years). The most notable finding was that the eyeballs were not centrally positioned within the orbits as the more recent craniofacial identification literature expounds. Rather, the eyeballs were consistently positioned closer to the orbital roof and lateral orbital wall (by 1–2 mm on average); a finding consistent with the earlier anatomical literature. While these estimation errors are small ipsilaterally, several factors make them meaningful: (i) the orbital region is heavily used for facial recognition; (ii) the width error is doubled because the eyes are bilateral structures; (iii) the eyes are sometimes used to predict/assess other soft tissue facial structures; and (iv) the net error in facial approximation rapidly accumulates with the subsequent prediction of each independent facial feature. While the small sample size of this study limits conclusive generalizations, the new data presented here nonetheless have immediate application to craniofacial identification practice because the results are evidence based. In contrast, metric data have never been published to support the use of the central positioning guideline. Clearly, this study warrants further quantification of the eyeball position in larger samples and preferably of younger individuals.
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ABSTRACT: 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... more
ABSTRACT: 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 methods. Full descriptive statistics were calculated for measurements made in this study and means, medians, and modes were reported. Differences between mean values for males and females were found to be minimal (2.2 mm or less) and considerable overlap was found between the groups. There were no statistically significant differences between the soft tissue depths of the sexes (P>0.05). These findings indicate that differences between male and female soft tissue depths are of little practical significance for craniofacial identification and, therefore, data (means, standard deviations, and sample sizes) reported for Australians were pooled across the sexes and the studies. Although these new pooled means have increased statistical power, data distributions at some landmarks were skewed and thus emphasis is placed on median and modes reported for this study rather than upon the collapsed data means.
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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
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 muscle and finds that highly pertinent anatomical and metric data to be available despite being overlooked in the FR literature. This includes variance and means of the perimeter dimensions, thicknesses, cross-sectional areas, volumes, metrics associated with muscle attachment, and correlations with other biological and craniometric variables (such as sex, age, tooth loss, cranial breadths, facial heights, alveolar thicknesses, and gonial angles). The oversight of these metric data adds to a general pattern seen for other hallmark structures of the face in FR and, taken together, these observations hold major ramifications for longstanding debates of FR accuracy, reliability, and error. Irrespectively, the data reviewed in this manuscript help set an improved basis for quantification of FR techniques.
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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... more
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 &amp;amp;quot;anatomical&amp;amp;quot; methods ironically forces one of the two large masticatory muscles to be exaggerated beyond reality. To demonstrate and resolve this issue the temporal region of nineteen caucasoid human cadavers (10 females, 9 males; mean age=84 years, s=9 years, range=58-97 years) were investigated. Soft tissue depths were measured at regular intervals across the temporal fossa in 10 cadavers, and the thickness of the muscle and fat components quantified in nine other cadavers. The measurements indicated that the temporalis muscle generally accounts for &amp;amp;lt;50% of the total soft tissue depth, and does not fill the entirety of the fossa (as generally known in the anatomical literature, but not as followed in facial approximation practice). In addition, a soft tissue bulge was consistently observed in the anteroinferior portion of the temporal fossa (as also evident in younger individuals), and during dissection, this bulge was found to closely correspond to the superficial temporal fat pad (STFP). Thus, the facial surface does not follow a simple undulating curve of the temporalis muscle as currently undertaken in facial approximation methods. New metric-based facial approximation guidelines are presented to facilitate accurate construction of the STFP and the temporalis muscle for future facial approximation casework. This study warrants further investigations of the temporalis muscle and the STFP in younger age groups and demonstrates that untested facial approximation guidelines, including those propounded to be anatomical, should be cautiously regarded.
Research Interests: Forensic Anthropology, Forensic Science, Aging, Face, Multidisciplinary, and 5 moreHumans, Female, Male, Aged, and Middle Aged
Abstract: 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... more
Abstract: 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 limits of such small samples, this study re-examined globe position in nine new cadavers to help clarify which relationship is accurate. The results essentially confirm prior empirical findings except that the mean lateral divergences from the orbit center were found to be larger—the eyeball was found to be “displaced” 1.4 mm superiorly and 2.4 mm laterally. Medians calculated across all 13 cadavers from this study and the above-mentioned recent report refine these measurements to 1.4 and 2.3 mm respectively. Globe projection values were identical to those observed for living individuals (c. 16 mm).
Research Interests: Forensic Anthropology, Forensic Science, Biometry, FORENSIC, Humans, and 9 moreForensic Sciences, Female, Male, Clinical Sciences, Eye, Cadaver, Aged, Globe, and Orbit
ABSTRACT: 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... more
ABSTRACT: 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, literature searches outside the usual realm of English publications reveal key papers that demonstrate that the Russian category above has been founded on distorted views. In reality, Russian methods are based on limited face muscle construction, with heavy reliance on modified average soft-tissue depths. A closer inspection of the American method also reveals inconsistencies with the recognized classification scheme. This investigation thus demonstrates that all major methods of facial approximation depend on both face anatomy and average soft-tissue depths, rendering common method classification schemes redundant. The best way forward appears to be for practitioners to describe the methods they use (including the weight each one gives to average soft-tissue depths and deep face tissue construction) without placing them in any categorical classificatory group or giving them an ambiguous name. The state of this situation may need to be reviewed in the future in light of new research results and paradigms.
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Abstract: 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... more
Abstract: 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 approximation were comparable across two different assessment methods (resemblance ratings and simultaneous face array tests using unfamiliar assessors) and if resemblance ratings co-varied with recognition responses. True-positive recognition performance from the facial approximation was poor (21%) while resemblance scores using the same facial approximation were moderately high (3 out of 5 on a five-point scale). These results are not, therefore, consistent and indicate that either different variables are being evaluated by the methods, or the same variable is being examined but with different weight/calibration. Further resemblance ratings tests of the facial approximation to three foil faces from the face array revealed that resemblance scores were similar irrespective of which face was compared, and did not closely correspond with the degree of recognition performance. This was especially the case for isolated comparisons of single faces to the facial approximation. Collectively, these results indicate that resemblance ratings are: (i) insensitive measures of a facial approximation’s accuracy; and (ii) inconsistent with results of unfamiliar simultaneous face-array recognition results. These data suggest that familiar and unfamiliar recognition tests should be given increased weight in contrast to current resemblance rating tests.
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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,... more
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 improved beyond the accuracy obtained when using mean values. Some authors have suggested that relationships between exophthalmos, height, interpupillary distance, and interorbital distance exist and it has been reported that these latter variables can be used to estimate eyeball projection. However, crucial tests are yet to be conducted. This study measures these variables and tests the accuracy of exophthalmometry means, a previously proposed prediction equation, and newly derived regression equations to determine which methods provide the best results. Data indicate that variation in exophthalmos is fairly small and as such prediction from other variables, like body height, are weak; thus, exophthalmometry means currently offer the best practical method of prediction. It should be noted that up to 2 mm error from either side of the mean is expected for 68% of cases.
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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... more
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 tested are those described by: 1) Gerasimov ([1971] The Face Finder; London: Hutchinson & Co.), using the distal third of the nasal bones and the nasal spine; 2) Krogman ([1962] The Human Skeleton in Forensic Medicine; Springfield: Charles C. Thomas), using the average soft-tissue depth at midphiltrum, plus three times the length of the nasal spine (and a variation of this technique: plus three times the distance of the tip of the nasal spine from the nasal aperture); 3) Prokopec and Ubelaker ([2002] Forensic Sci Commun 4:1–4), using the reflected profile line of the nasal aperture; and 4) George ([1987] J Forensic Sci 32:1305–1330), using a variation of the Goode method. Four identical hard-tissue tracings were made of 59 adult lateral head cephlograms (29 males, mean age 24, SD 10 years; 30 females, mean age 23, SD 5 years) on separate sheets of tracing paper. One soft-tissue tracing was also made for each radiograph. All tracings were marked with three identical reference points. Soft-tissue tracings were isolated from one of us (C.N.S.), who attempted under blind conditions to predict pronasale position and nose projection on the hard-tissue tracings, using the soft-tissue prediction guides above. Actual soft-tissue tracings were then compared to each of the predicted tracings, and differences in projection/pronasale position were measured. Results indicate that for nose projection, methods 3 and 4 performed well, while methods 1 and 2 performed poorly. Features which are most related to nose projection/pronasale are described in this paper, as are regression equations generated from these variables that predict pronasale/nose projection better than the traditional methods mentioned above. The results of this study are significant because they: 1) indicate that the popular facial approximation methods used to build the nose are inaccurate and produce incorrect nose anatomy; and 2) indicate that the new pronasale prediction methods developed here appear to have less error than traditional methods. Am J Phys Anthropol, 2003. © 2003 Wiley-Liss, Inc.
Research Interests: Evolutionary Biology, Archaeology, Anthropology, Forensic Science, Methodology, and 18 moreAnthropometry, Prediction, Face, Physical Anthropology, Morphometry, American Journal of Physical Anthropology, Cephalometry, Humans, Female, Skull, Male, Regression Analysis, Estimation, American, Adult, Soft Tissue, Sensitivity and Specificity, and Nose
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... more
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 to the distance between the pupils; 2) that mouth width is equal to the distance between the medial borders of the iris; and 3) that mouth width is equal to the distance between the most lateral junctions of the canines and the first premolars. The study primarily examines living Australian European and Central/South East Asian participants (of both sexes) using photogrammetric methods. The results of this study indicate that methods 1 and 3 are highly inaccurate. Method 1 overestimated mouth width, on average, by ∼11 mm (SD, 4 mm), while method 3 underestimated mouth width by ∼13 mm (SD, 3 mm). Method 2 was the most accurate of the methods evaluated, but on average underrepresented mouth width by ∼2 mm (SD, 4 mm). All three methods produced mouth-width predictions that, in general, were statistically different from actual mouth widths (P < 0.05). A new guideline, describing mouth width as canine width plus 57% of the cumulative distance between the lateral canine borders and the pupil centers on each side was found not to differ at statistically significant levels from actual mouth widths (P > 0.05). On average, this guideline did not under/overestimate actual mouth width, with the difference between them being 0 mm (SD, 3 mm). The increased accuracy of this new guideline in comparison to others suggests that it is the most appropriate for facial approximation. However, it should be further tested using independent samples. The finding that commonly used mouth-width prediction guidelines are not accurate suggests that many facial approximations previously made have incorrect mouth widths. This could reduce the recognition of these facial approximations and may, especially if other guidelines are inaccurate, render the facial approximations unrecognizable as their respective target individual (individual to whom the skull belongs). Am J Phys Anthropol 121:000–000, 2003. © 2003 Wiley-Liss, Inc.
Research Interests: Evolutionary Biology, Archaeology, Anthropology, Forensic Science, Photography, and 19 moreAnthropometry, Forecasting, Morphology, Face, Physical Anthropology, American Journal of Physical Anthropology, Anatomy, Humans, Measurement, Female, Method, Skull, Male, Skin, Laboratory, Eye, Adult, Mouth, and Sensitivity and Specificity
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... more
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 accurate positioning of subjects, in the natural head position, at precise distances from the frontal camera. Results of experiments examining the intraobserver error of multiple photographs taken on the rig indicate that high-quality, repeatable photographs can be taken after a reasonably large amount of time has lapsed between photography sessions (e.g., 30 days). This study also indicates that some variability remains between photographs even when highly standardized protocols are followed. Consequently, it is expected that the variation between photographs with limited standardization is much larger and more likely to cause significant errors in any comparisons.
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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... more
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 variation within each sex was large while the variation between the sexes was small. Often the value of two standard deviations of the measurement for either sex was larger than the difference displayed between the means of each sex. Furthermore, opposite sex overlap in regions defined to be close to the male or female mean were found to be large and the amount of variance explained by sex was small (less than 6% on average). These results indicate that while male and female means at single craniofacial landmarks may differ slightly, and even at statistically significant levels, individual male and female soft tissue depths are often the same or very similar. On average, soft tissue depths of the face do display some sexual dimorphism but it is not marked and of little practical meaning for craniofacial identification where a single individual must be independently considered. Thus, there is little use in separate reporting of data for males and females and data should be combined to increase sample sizes.
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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... more
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 (&amp;amp;lt;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 &amp;amp;lt;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.
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Abstract: 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... more
Abstract: 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 produce a manageable soft tissue depth library. While a principal components analysis would provide the best foundation for such an assessment, this type of investigation is not currently possible because of a lack of easily accessible raw data (first, many studies are narrow; second, raw data are infrequently published and/or stored and are not always shared by some authors). This paper provides an alternate means of investigation using an hierarchical approach to review and compare the effects of single variables on published mean values for adults whilst acknowledging measurement errors and within-group variation. The results revealed: (i) no clear secular trends at frequently investigated landmarks; (ii) wide variation in soft tissue depth measures between different measurement techniques irrespective of whether living persons or cadavers were considered; (iii) no clear clustering of non-Caucasoid data far from the Caucasoid means; and (iv) minor differences between males and females. Consequently, the data were pooled across studies using weighted means and standard deviations to cancel out random and opposing study-specific errors, and to produce a single soft tissue depth table with increased sample sizes (e.g., 6786 individuals at pogonion).