Ensemble-Based Bounding Box Regression for Enhanced Knuckle Localization.

The knuckle creases present on the dorsal side of the human hand can play significant role in identifying the offenders of serious crime, especially when evidence images of more recognizable biometric traits, such as the face, are not available. These knuckle creases, if localized appropriately, can result in improved identification ability. This is attributed to ambient inclusion of the creases and minimal effect of background, which lead to quality and discerning feature extraction. This paper presents an ensemble approach, utilizing multiple object detector frameworks, to localize the knuckle regions in a functionally appropriate way. The approach leverages from the individual capabilities of the popular object detectors and provide a more comprehensive knuckle region localization. The investigations are completed with two large-scale public hand databases which consist of hand-dorsal images with varying backgrounds and finger positioning. In addition to that, effectiveness of the proposed approach is also tested with a novel proprietary unconstrained multi-ethnic hand dorsal dataset to evaluate its generalizability. Several novel performance metrics are tailored to evaluate the efficacy of the proposed knuckle localization approach. These metrics aim to measure the veracity of the detected knuckle regions in terms of their relation with the ground truth. The comparison of the proposed approach with individual object detectors and a state-of-the-art hand keypoint detector clearly establishes the outperforming nature of the proposed approach. The generalization of the proposed approach is also corroborated through the cross-dataset framework.

Nose profile morphology and accuracy study of nose profile estimation method in Scottish subadult and Indonesian adult populations.

This study investigated nose profile morphology and its relationship to the skull in Scottish subadult and Indonesian adult populations, with the aim of improving the accuracy of forensic craniofacial reconstruction. Samples of 86 lateral head cephalograms from Dundee Dental School (mean age, 11.8 years) and 335 lateral head cephalograms from the Universitas Padjadjaran Dental Hospital, Bandung, Indonesia (mean age 24.2 years), were measured. The method of nose profile estimation based on skull morphology previously proposed by Rynn and colleagues in 2010 (FSMP 6:20-34) was tested in this study. Following this method, three nasal aperture-related craniometrics and six nose profile dimensions were measured from the cephalograms. To assess the accuracy of the method, six nose profile dimensions were estimated from the three craniometric parameters using the published method and then compared to the actual nose profile dimensions.In the Scottish subadult population, no sexual dimorphism was evident in the measured dimensions. In contrast, sexual dimorphism of the Indonesian adult population was evident in all craniometric and nose profile dimensions; notably, males exhibited statistically significant larger values than females. The published method by Rynn and colleagues (FSMP 6:20-34, 2010) performed better in the Scottish subadult population (mean difference of maximum, 2.35 mm) compared to the Indonesian adult population (mean difference of maximum, 5.42 mm in males and 4.89 mm in females).In addition, regression formulae were derived to estimate nose profile dimensions based on the craniometric measurements for the Indonesian adult population. The published method is not sufficiently accurate for use on the Indonesian population, so the derived method should be used. The accuracy of the published method by Rynn and colleagues (FSMP 6:20-34, 2010) was sufficiently reliable to be applied in Scottish subadult population.

The persistence of epiphyseal scars in the distal radius in adult individuals.

The use of radiographic imaging in the estimation of chronological age facilitates the analysis of structures not visible on gross morphological inspection. Following the completion of epiphyseal fusion, a thin radio-opaque band, the epiphyseal scar, may be observed at the locus of the former growth plate. The obliteration of this feature has previously been interpreted as the final stage of skeletal maturation and consequently has been included as a criterion in several methods of age estimation, particularly from the distal radius. Due to the recommendations relating to age estimation in living individuals, accurate assessment of age from the distal radius is of great importance in human identification; however, the validity of the interpretation of the obliteration of the epiphyseal scar as an age-related process has not been tested. A study was undertaken to assess the persistence of epiphyseal scars in adults between 20 and 50 years of age through the assessment of 616 radiographs of left and right distal radii from a cross-sectional population. This study found that 86% of females and 78% of males retained some remnant of the epiphyseal scar in the distal radius. The relationships between chronological age, biological sex and the persistence of the epiphyseal scar were not statistically significant. The findings of this study indicate that the epiphyseal scars may persist in adult individuals until at least 50 years of age. No maximum age should therefore be applied to the persistence of an epiphyseal scar in the distal radius.

Testing the reliability of hands and ears as biometrics: the importance of viewpoint.

Two experiments are presented to explore the limits when matching a sample to a suspect utilising the hand as a novel biometric. The results of Experiment 1 revealed that novice participants were able to match hands at above-chance levels as viewpoint changed. Notably, a moderate change in viewpoint had no notable effect, but a more substantial change in viewpoint affected performance significantly. Importantly, the impact of viewpoint when matching hands was smaller than that when matching ears in a control condition. This was consistent with the suggestion that the flexibility of the hand may have minimised the negative impact of a sub-optimal view. The results of Experiment 2 confirmed that training via a 10-min expert video was sufficient to reduce the impact of viewpoint in the most difficult case but not to remove it entirely. The implications of these results were discussed in terms of the theoretical importance of function when considering the canonical view and in terms of the applied value of the hand as a reliable biometric across viewing conditions.

The epiphyseal scar: changing perceptions in relation to skeletal age estimation.

BACKGROUND: It is imperative that all methods applied in skeletal age estimation and the criteria on which they are based have a strong evidential basis. The relationship between the persistence of epiphyseal scars and chronological age, however, has remained largely untested. AIMS: To assess the relationships between the level of persistence of the epiphyseal scar and chronological age, biological sex and side of the body in relation to the interpretation of epiphyseal scars in methods of skeletal age estimation. SUBJECTS AND METHODS: A sample of radiographic images was obtained from the Tayside NHS Trust, Ninewells Hospital, Dundee, UK. This included images of four anatomical regions from living female and male individuals aged between 20-50 years. RESULTS: Some remnant of an epiphyseal scar was found in 78-99% of individuals examined in this study. The level of persistence of epiphyseal scars was also found to vary between anatomical regions. CONCLUSION: The overall relationship between chronological age and the level of persistence or obliteration of the epiphyseal scar was found to be of insufficient strength to support a causative link. It is, therefore, necessary that caution is employed in their interpretation in relation to skeletal age estimation practices.

Use of data to inform expert evaluative opinion in the comparison of hand images-the importance of scars.

Evaluation of a likelihood ratio is widely recognised as the most logical and appropriate means of assessing and expressing the weight of expert scientific evidence. This paper describes the application of such an approach to cases involving the comparison of images of hands that contain visible scars. Such evidence is frequently provided in cases of alleged child sexual abuse in which images of the perpetrator's hand are compared with images of the suspect/accused's hand. We illustrate how data provided from a database of hand images can be used to inform the probabilities that are an essential part of evaluating a likelihood ratio and, hence, how data have a bearing on the appraisal of the weight of evidence that can be attributed when scars are present within an image.

The persistence of epiphyseal scars in the adult tibia.

Estimation of chronological age from skeletal material is dependent upon estimation of maturational stage observed. Following completion of epiphyseal fusion, a transverse radio-opaque line, termed "epiphyseal scar", may be observed in the region of the former growth plate. According to the literature, this line is likely to become obliterated shortly after completion of epiphyseal fusion. Consequently, presence of an epiphyseal scar has been interpreted as an indication of recent epiphyseal fusion; however, this has not been validated by quantitative research. A study was undertaken to determine persistence of the epiphyseal scars in a cross-sectional population of adults between 20 and 50 years of age. This study examined 1,216 radiographs of proximal and distal tibiae from both sexes and sides of the body. This study suggested that 98.05% of females and 97.74% of males retained some remnant of the epiphyseal scar at the proximal tibia whilst 92.72% of females and 92.95% of males retained some remnant of the epiphyseal scar at the distal tibia. General linear model (GLM) analysis determined that chronological age accounted for 2.7% and 7.6% of variation in persistence of the epiphyseal scar at the proximal and distal tibiae, respectively. This study suggests that obliteration of the epiphyseal scar is not as dependent on chronological age as previously thought. It is, therefore, recommended that this feature not be used as an indicator of chronological age during forensic age assessment.

The incidence of scarring on the dorsum of the hand.

When undertaking image comparison of the hand between accused and perpetrator, it is not unusual for scars to be identified on the back of the hand. To investigate the occurrence of scarring in a discreet sample, a database of 238 individuals was examined, and the dorsum of the right and left hands was gridded for each individual. The position, size and type of scar were recorded within each grid. It was found that, in general, males exhibited a higher incidence of scarring than females. However, males were more likely to show scarring on their left hand whereas females were more likely to exhibit scarring on their right hand. Contrary to the literature, scarring was not most prevalent along the borders of the hand but occurred more frequently in association with the index and middle finger corridor regions. Surgical scars were rare as were large scars whereas linear scars smaller than 6 mm were the most frequently identified. Close to half of the sample did not exhibit scarring on one hand. The importance of understanding the pattern of scarring on the back of the hand is discussed in the light of forensic image comparison analysis.

Postmortem computed tomography age assessment of juvenile dentition: comparison against traditional OPT assessment.

Age estimation is one of the primary demographic features used in the identification of juvenile remains. Determining the accuracy and repeatability of age estimations based on postmortem computed tomography (PMCT) data compared with those using conventional orthopantomography (OPT) images is important to validate the use of PMCT as a single imaging technique in forensic and disaster victim identification (DVI). In this study, 19 juvenile mandibles and maxilla of known age underwent both OPT and PMCT. Three raters then estimated dental age using the resulting images and 3D reconstructions. This assessment showed excellent agreement between the age estimations using the two techniques for all three observers. PMCT also offers a greater range of measurements for both the dentition and the whole human skeleton using a single image acquisition and therefore has the potential to improve both the speed and accuracy of age estimation.

The developing juvenile ischium: macro-radiographic insights.

Despite the importance of the human pelvis as a weight-bearing structure, there is a paucity of literature that discusses the development of the juvenile innominate from a biomechanical perspective. This study aims to add to the limited body of literature pertaining to this topic through the qualitative analysis of the gross architecture of the human ischium during the juvenile period. Macro-radiographs of 55 human ischia ranging from 28 intra-uterine weeks to 14 years of age were examined using intensity-gradient color mapping to highlight changes in gross structural morphology with increasing age. A clear pattern of maturation was observed in the juvenile ischium with increasing age. The acetabular component and ramus of the ischium consistently displayed low bone intensity in the postnatal skeletal material. Conversely the posterior body of the ischium, and in particular the ischial spine and lesser sciatic notch, exhibited increasing bone intensity which first arose at 1-2 years of age and became more expansive in older cohorts. The intensity patterns observed within the developing juvenile ischium are indicative of the potential factors influencing the maturation of this skeletal element. While the low intensity acetabular fossa indicates a lack of significant biomechanical interactions, the posterior increase in bone intensity may be related to the load-bearing nature of the posterior ischium.

A minimum data set approach to post-mortem computed tomography reporting for anthropological biological profiling.

Anthropological examination of bones is routinely undertaken in medico-legal investigations to establish an individual's biological profile, particularly their age. This often requires the removal of soft tissue from bone (de-fleshing), which, especially when dealing with the recently deceased, is a time consuming and invasive procedure. Recent advances in multi-detector computed tomography have made it practical to rapidly acquire high-resolution morphological skeletal information from images of "fleshed" remains. The aim of this study was to develop a short standard form, created from post-mortem computed tomography images, that contains the minimum image-set required to anthropologically assess an individual. The proposed standard forms were created for 31 juvenile forensic cases with known age-at-death, spanning the full age range of the developing human. Five observers independently used this form to estimate age-at-death. All observers estimated age in all cases, and all estimations were within the accepted ranges for traditional anthropological and odontological assessment. This study supports the implementation of this approach in forensic radiological practice.

A test of the Whitaker scoring system for estimating age from the bones of the foot.

Within the literature pertaining to skeletal age estimation, there is a paucity of statistically validated methods of age estimation from the foot. Given the prevalence of recovery of pedal elements in isolation, it is critical that methods exist to facilitate the estimation of age from this anatomical region and that those methods be tested to ensure they are reliable, repeatable and statistically robust. A study was carried out to determine the validity of using the Whitaker method of age estimation from the bones of the foot as a tool in forensic age estimation within a modern Scottish population. Two-hundred and sixty radiographs from individuals aged between birth and 18 years were assessed according to the Whitaker method; the results were compared with chronological age. The results of this study suggest that the method of Whitaker et al. is highly unlikely to estimate the age of females below 16 years of age or males below 18 years of age correctly. When the methodology was altered to correspond with best practice principles of age estimation, the estimated age ranges were found to be too wide to be of practical value in forensic age estimation. The results of this study therefore suggest that the Whitaker method for estimating age from the bones of the foot should not be used in forensic age assessment.

The vascular collar of the ilium: three-dimensional evaluation of the dominant nutrient foramen.

Nutrient arteries are the predominant blood supply to endochondral bones and are particularly important during the early stages of endochondral ossification and the active growth period. These nutrient vessels traverse the periosteal shell of a developing bone to invade the disintegrating cartilage matrix and bring about endochondral bone formation. This results in the formation of a nutrient foramen which is retained as the vascular conduit between the exterior and interior of the bone. This study examined the dominant nutrient foramen of the neonatal ilium using high resolution micro-computed (micro-CT) tomography. Three-dimensional reconstruction of micro-CT data consistently demonstrated the presence of a distinctive, yet poorly reported, collar of bone extending into the trabecular cavity beyond the endosteum. This study proposes that this collar of bone may have formed in response to osteogenic signaling from approximated arterial vasculature. Additionally, it is suggested that the formation of this collar may act as a protective mechanism to the dominant nutrient vessel and as a potential biomechanical anchor for surrounding trabeculae, aiding to increase the biomechanical competency around the area of the foramen. The documentation of this osteological structure is important from a clinical perspective to prevent the misinterpretation of fracturing and pathology on plain plate radiographs and clinical computed tomography scans.

Test of age-related variation in the craniometry of the adult human foramen magnum region: implications for sex determination methods.

Sex differences in the foramen magnum region of the cranial base have been identified with varying rates of success. Recent publications demonstrate a continuing strong interest in metric analysis of the foramen magnum region for sex determination despite the generally low expression of cranial base sexual dimorphism. It is important to identify possible age effects on skull base morphometric variables as most reported discriminant analyses use pooled-age samples without assessing the influence of aging on sexual dimorphism. This study examined 135 adult cranial bases (69 males and 66 females) from the St. Bride's documented skeletal collection in London. Traditional craniometric measurements were recorded and the effect of age on sexual dimorphism of this anatomical region was tested using a variety of statistical analyses including MANOVA and discriminant function analysis. Age-dependent discriminant functions for <50 and >50 years of age were developed and compared. The cross-validated results showed that the <50 years function determined the sex of 69.1% correctly while the >50 years function achieved 81.3% correct predictions. However, the high sex biases of these functions (14.4% and -17.5%) severely limit their practical application. A pooled-age discriminant function permitted 71.9% correct prediction with a sex bias of only -1.7%. The statistical analyses also showed no significant age effect on any of the variables, suggesting that a separation by age is not necessary for the development of sex determination methods.

Post-mortem computed tomography and 3D imaging: anthropological applications for juvenile remains.

Anthropological examination of defleshed bones is routinely used in medico-legal investigations to establish an individual's biological profile. However, when dealing with the recently deceased, the removal of soft tissue from bone can be an extremely time consuming procedure that requires the presence of a trained anthropologist. In addition, due to its invasive nature, in some disaster victim identification scenarios the maceration of bones is discouraged by religious practices and beliefs, or even prohibited by national laws and regulations. Currently, three different radiological techniques may be used in the investigative process; plain X-ray, dental X-ray and fluoroscopy. However, recent advances in multi-detector computed tomography (MDCT) mean that it is now possible to acquire morphological skeletal information from high resolution images, reducing the necessity for invasive procedures. This review paper considers the possible applications of a virtual anthropological examination by reviewing the main juvenile age determination methods used by anthropologists at present and their possible adaption to MDCT.

Facial average soft tissue depth variation based on skeletal classes in Indonesian adult population: A retrospective lateral cephalometric study.

OBJECTIVE: To understand the influence of three types of skeletal classes (Class I, Class II and Class III) on midline average soft tissue depth (ASTD). METHODS: Lateral cephalograms of 335 pre-treatment orthodontic patients were obtained from the archive of Radiology Clinic Universitas Padjadjaran Dental Hospital Bandung Indonesia. The linear measurements of 10 midline facial landmarks ASTD and angular measurement of ANB were extracted and analysed statistically. RESULTS: A database of ASTD grouped by skeletal classes, specific for the Indonesian population, within the South East Asian ancestry group was obtained. CONCLUSIONS: A generic pattern of deeper upper lip than lower lip in class III compared to class II and conversely, deeper lower lip than upper lip in class II compared to class III, was visible in both male and female groups.

Development of the fetal ilium--challenging concepts of bipedality.

Macroradiographs of 30 human fetal and neonatal ilia were analysed to investigate the early pattern of trabecular bone organization prior to the influences of direct weight-bearing locomotion. Consistent and well-defined patterns of internal organization were identified within the fetal and neonatal ilium, which correspond with previously recognized regions that have been attributed directly to forces associated with bipedal locomotion. This study proposes that patterns previously attributed to weight-bearing locomotive responses are present in the earliest stages of the development of this bone. It is suggested that the rudimentary scaffold seen in the fetal and neonatal ilium could indicate a predetermined template upon which locomotive influences may be superimposed and perhaps reinforced at a later age. Alternatively, this early pattern may mimic the adult form due to the effects of in-utero limb movement activity even though it is not weight bearing. This is a preliminary study that will be supported in a further communication with three-dimensional micro-computed trabecular analysis.

Iliac cortical thickness in the neonate - the gradient effect.

Recent studies of the neonatal ilium are beginning to reveal that a recognizable structural patterning of trabecular bone is present in the absence of any direct stance-related weight transfer. However, little is known about the organization of compact bone in the ilium and the way in which it is laid down during the earliest stages of development. This study investigates cortical bone thickness across both gluteal and pelvic iliac shells in the human neonatal ilium. Measurements of specific regions of interest on the iliac cortices were recorded using reconstructed micro-computed tomography scans from 30 neonatal ilia. Analysis of gluteal and pelvic cortical thicknesses revealed a distinctive patterning consistent with the expected bone distribution achieved through early bone modelling and remodelling. The analysis of this pattern is important for understanding the relationship between trabecular bone patterning and cortical bone structure in the earliest stages of pelvic development prior to locomotive influences and its response to the specific functional forces acting during this period.

Anticipating bipedalism: trabecular organization in the newborn ilium.

Trabecular bone structural organization is considered to be predominantly influenced by localized temporal forces which act to maintain and remodel the trabecular architecture into a biomechanically optimal configuration. In the adult pelvis, the most significant remodelling forces are believed to be those generated during bipedal locomotion. However, during the fetal and neonatal period the pelvic complex is non-weight bearing and, as such, structural organization of iliac trabecular bone cannot reflect direct stance-related forces. In this study, micro-computed tomography scans from 28 neonatal ilia were analysed, using a whole bone approach, to investigate the trabecular characteristics present within specific volumes of interest relevant to density gradients highlighted in a previous radiographic study. Analysis of the structural indices bone volume fraction, trabecular thickness, trabecular spacing and trabecular number was carried out to quantitatively investigate structural composition. Quantification of the neonatal trabecular structure reinforced radiographic observations by highlighting regions of significant architectural form which grossly parallel architectural differences in the adult pattern but which have previously been attributed to stance-related forces. It is suggested that the seemingly organized rudimentary scaffold observed in the neonatal ilium may be attributable to other non-weight bearing anatomical interactions or even to a predetermined genetic blueprint. It must also be postulated that whilst the observed patterning may be indicative of a predetermined inherent template, early non-weight bearing and late stance-related locomotive influences may subsequently be superimposed upon this scaffolding and perhaps reinforced and likely remodelled at a later age. Ultimately, the analysis of this fundamental primary pattern has core implications for understanding the earliest changes in pelvic trabecular architecture and provides a baseline insight into future ontogenetic development and bipedal capabilities.