Comparison of the reverse scan technique with an intraoral scanner and the traditional impression technique.

STATEMENT OF PROBLEM: Intraoral scanners have many advantages but have limited applicability for extensive tooth-supported or implant-supported prostheses because of merging errors. PURPOSE: The purpose of this study was to compare the reverse scan technique (RST) with an intraoral scanner using the traditional impression technique both in vitro and in vivo. MATERIAL AND METHODS: A participant was scanned 10 times with an intraoral scanner. Then, the RST was performed 3 times in the oral cavity. One of the intraoral scans was chosen to make a 3-dimensionally (3D) printed cast. The printed cast was scanned 10 times with a laboratory scanner (Control cast) and 10 times with an intraoral scanner (IOS cast). The RST was performed 10 times (RST cast), and 10 dental impressions were made using the traditional splinted technique on the same cast (Impression cast). A laboratory scanner was used to obtain standard tessellation language (STL) files of the tested methods. A newly developed pyramid replacement method was used to evaluate accuracy. This method uses modified virtual abutments with integrated pyramids that determine the exact measurement points. The obtained data were processed using Procrustes analysis and statistically analyzed (α=.05). RESULTS: The Procrustes distances were Control cast 0 to 0.4 µm (median 0.3 µm), RST cast 5.6 to 6.9 µm (median 6.2 µm), Impression cast 5.4 to 7.1 µm (median 6.5 µm), and IOS cast group 4.5 to 41.2 µm (median 5.8 µm). In the participant, the Procrustes distance values were RST intraoral 9.5 to 9.6 µm (median 9.5 µm) and IOS intraoral 5.7 to 18.3 µm (median 10.9 µm). CONCLUSIONS: The reverse scan technique is an acceptable fully digital replacement for traditional impression making. Using an IOS to obtain a 3D cast of an implant-supported interim prosthesis with scannable implant analogs is not recommended. It is more beneficial to use laboratory scanners rather than intraoral scanners for the digitization of precision improvement devices such as bonded interim implant-supported prostheses with a scannable implant analog or solid index.

Virtual fit and design improvements of a filtering half-mask for sub-adult wearers.

The recent pandemic has shown that protecting the general population from hazardous substances or pathogens can be a challenging and urgent task. The key element to adequate protection is appropriately sized, well-fitted and sufficiently distributed personal protective equipment (PPE). While these conditions are followed for adult PPE wearers, they are less considered when it comes to protecting subadults. In this study, the assessment of the fit and design improvements of a 3D-printed facial half mask for subadult wearers (4-18 years) is designed. The target population was represented by 1137 subadults, aged 4.06-18.94 years, for whom 3D face models were acquired. The half mask tested, which was originally provided in one subadult size, did not fit appropriately the target population. This finding prompted the creation of four size categories using the age-dependent distribution of the centroid size calculated from 7 facial landmarks. For each size category, a modified half-mask virtual design was created, including resizing and reshaping, and fit was evaluated visually and numerically using averaged and random 3D face representatives.Practitioner summary: The reason for this study was to describe procedures which led to design improvement of an existing half-mask and provide respiratory protection for subadults. To address this, fit was assessed using an innovative metric approach. Four sizes were then created based on centroid size, resulting in improved fit and design.Abbreviations: CH: cheilion landmark; CS: centroid size; EX: exocanthion landmark; GN: gnathion landmark; N: nasion landmark; PPE: personal protective equipment; PR: pronasale landmark; RPE: respiratory protective equipment.

3D human face dataset was used for modifying and validating protective equipment for subadultsTo ensure optimal protection for subadults, four size categories were proposed based on 3D face landmarks and centroid sizeModified half-mask design fit was validated virtually using a visual and numerical approach.

Maxillary Sinus Volume and Its Effect on Treated Impacted Canines.

The goal of study was to explore the role of 3D CBCT (cone beam computer tomography) in detecting impacted canines and their movement to evaluate the influence of orthodontic therapy parameters on treatment options, and to monitor quality of healing process based on shape and size of sinus maxillae volume. It is known that the volume of maxillary sinus plays an important role in patients with impacted teeth. The prospective study consisted of 26 individuals. For each individual, pre-treatment and post-treatment CBCT data were acquired. Changes of size, and position of impacted canine in 3D CBCT image before and after therapy were prepared using 3D reconstruction. Volumetric measurements of the maxillary sinuses were performed before and after orthodontic therapy of impacted canines, using InVivo6 software. The main effects MANOVA performed on linear measurements showed metric differences between pre-op and post-op images. A paired t-test showed no statistically significant differences between pre-op and post-op values of the sinus volume. Changes of size and position of impacted canine in 3D image before and after therapy were precise and reproducible, using 3D reconstruction in three planes - horizontal, midsagittal, and coronal. The linear measurements showed metric differences between pre-op and post-op images.

Studying factors influencing facial developmental instability.

BACKGROUND: Developmental instability is a component of non-genetic variation that results from random variation in developmental processes. It is considered a sensitive indicator of the physiological state of individuals. It is reflected in various ways, but in this study we focussed on its reflection in fluctuating asymmetry (FA) and morphological integration. AIM: To assess how, if at all, variations of facial morphology mirror developmental instability across childhood with respect to sex, growth rate and socioeconomic/environmental factors. SUBJECTS AND METHODS: A set of 210 three-dimensional facial models (of children aged between 6.3 and 14.3 years) originating from the FIDENTIS 3D Face Database was subjected to landmark-based methods of geometric morphometrics to quantify the degree of facial asymmetry and facial morphological integration. In addition, the association with age, sex, and socioeconomic factors was assessed. RESULTS: Our results showed a nonlinear increase of FA with age up to the age of 14 years. The pattern of sex-related variants in facial FA differed in relation to age, as girls exhibited higher values of FA than boys up to the age of 9 years. We found that a signal of modularity based on functional demands and organisation of the face is of particular importance. Here, girls exhibited higher morphological covariation among modules. During more rapid adolescence-related growth, however, covariation among modules at the asymmetrical level decreased in both sexes. CONCLUSION: We can conclude that facial morphology was shown to be strongly integrated, particularly until adolescence. This covariation can facilitate an increase of FA. In addition, the results of this study indicate there is a weak association between socioeconomic stress and facial asymmetries. In contrast, sex and growth rate are reflected in developmental instability.

Family effects on the digit ratio (2D:4D): The role of the interbirth interval.

OBJECTIVES: Family represents the closest social environment that immediately affects human ontogeny from an early prenatal period. This study aimed to assess sibship influences on the second-to-fourth digit length ratio (2D:4D ratio). METHODS: The source sample represented 329 children aged 6.5 to 15.8 years (Czech Republic), including a subsample of 75 sibling pairs. A combination of (a) between-family design (cross-sectional sample) and (b) within-family design (pairs of siblings) was used to study the effect of family variables and interbirth interval (IBI) on the 2D:4D ratio. RESULTS: Birth order, number of siblings (except for younger sisters), and sex ratio in siblings were significantly related to the 2D:4D ratio on the right, left, or both hands. At the same time, the relationships were opposite in males and females for birth order, number of older brothers and number of children in the family--increasing values in these variables increased digit ratio in males but decreased digit ratio in females. Mean difference in 2D:4D ratio (DIFF) within pairs (older minus younger sibling) differed from zero only in the "older sister--younger brother" group, where DIFF did not depend on IBI. On the contrary, in remaining pair types the DIFF tended to change with IBI, the strongest in the "older brother--younger sister" pairs. CONCLUSIONS: Family variables, especially number of older brothers, should be considered as important confounding factors in 2D:4D ratio studies. However, the effect of these variables might be modified by IBI.

Agenesis of the superior cornua of the thyroid cartilage: a rare variant of medicolegal importance.

It is important that forensic pathologists are familiar with variations in the size and shape of the laryngohyoid complex when interpreting injuries and pathology of the head and neck region. Accurate postmortem examination of the laryngohyoid structures may be difficult if anatomical variation in these structures is present. Agenesis of the upper horns of the thyroid cartilage has medicolegal significance because it may be mistaken for a fracture or other trauma-related conditions. We present 3 cases with different forms of agenesis of the superior cornu of the thyroid cartilage, namely, right unilateral, left unilateral, and bilateral agenesis.

[The application of X-ray imaging in forensic medicine]. / Vyuzití RTG vysetrení v soudním lékarství

X-ray is the most common, basic and essential imaging method used in forensic medicine. It serves to display and localize the foreign objects in the body and helps to detect various traumatic and pathological changes. X-ray imaging is valuable in anthropological assessment of an individual. X-ray allows non-invasive evaluation of important findings before the autopsy and thus selection of the optimal strategy for dissection. Basic indications for postmortem X-ray imaging in forensic medicine include gunshot and explosive fatalities (identification and localization of projectiles or other components of ammunition, visualization of secondary missiles), sharp force injuries (air embolism, identification of the weapon) and motor vehicle related deaths. The method is also helpful for complex injury evaluation in abused victims or in persons where abuse is suspected. Finally, X-ray imaging still remains the gold standard method for identification of unknown deceased. With time modern imaging methods, especially computed tomography and magnetic resonance imaging, are more and more applied in forensic medicine. Their application extends possibilities of the visualization the bony structures toward a more detailed imaging of soft tissues and internal organs. The application of modern imaging methods in postmortem body investigation is known as digital or virtual autopsy. At present digital postmortem imaging is considered as a bloodless alternative to the conventional autopsy.

Head poses and grimaces: Challenges for automated face identification algorithms?

In today's biometric and commercial settings, state-of-the-art image processing relies solely on artificial intelligence and machine learning which provides a high level of accuracy. However, these principles are deeply rooted in abstract, complex "black-box systems". When applied to forensic image identification, concerns about transparency and accountability emerge. This study explores the impact of two challenging factors in automated facial identification: facial expressions and head poses. The sample comprised 3D faces with nine prototype expressions, collected from 41 participants (13 males, 28 females) of European descent aged 19.96 to 50.89 years. Pre-processing involved converting 3D models to 2D color images (256 × 256 px). Probes included a set of 9 images per individual with head poses varying by 5° in both left-to-right (yaw) and up-and-down (pitch) directions for neutral expressions. A second set of 3,610 images per individual covered viewpoints in 5° increments from -45° to 45° for head movements and different facial expressions, forming the targets. Pair-wise comparisons using ArcFace, a state-of-the-art face identification algorithm yielded 54,615,690 dissimilarity scores. Results indicate that minor head deviations in probes have minimal impact. However, the performance diminished as targets deviated from the frontal position. Right-to-left movements were less influential than up and down, with downward pitch showing less impact than upward movements. The lowest accuracy was for upward pitch at 45°. Dissimilarity scores were consistently higher for males than for females across all studied factors. The performance particularly diverged in upward movements, starting at 15°. Among tested facial expressions, happiness and contempt performed best, while disgust exhibited the lowest AUC values.

Photobiomodulation Therapy After Mesiodens Surgery: Evaluation of Immunological Markers and Three-Dimensional X-Ray Analysis-Placebo-Controlled Study.

Objective: Photobiomodulation therapy (PBMT) applies therapeutic lasers or light-emitting diodes radiation to the surface of the body. From the medical point of view, PBMT systems have been employed for reducing pain, inflammation, and edema, promoting healing of wounds, deeper tissues and nerves, preventing tissue damage, etc. Background data: PBMT or biostimulation has a wide range of applications in maxillofacial surgery. It is known that the therapy effect using three-dimensional (3D) image was not really clear during the healing process. Materials and methods: The treatment group comprised 38 patients, 18 of them were treated with laser radiation (diode laser 808 nm) and 20 patients presented the control group. The surgery plan was monitored using cone beam computed tomography, in particular the number, shape, and size of mesiodens were registered. The effectivity of laser therapy was assessed based on immunological tests-secretory immunoglobulin A (sIgA) and lysozyme levels measured in nonstimulated saliva before and after treatment. Results: For sIgA (both in millimeters and milligrams per liter), the measurements displayed differences between pre- and postsurgery values, the postsurgery values being significantly lower than the presurgery values. In addition, interaction with the laser treatment plan was found, meaning that the laser treatment affected the sIgA levels. The decrease in sIgA levels in the control group was statistically significant. However, there was no significant change in sIgA levels in the laser group. The lysozyme trends appeared to be identical to the sIgA levels, that is, rising in the laser group and decreasing in the control group. The initial values for each group, however, go in the opposite direction. Conclusions: The study has shown that the 3D techniques and technologies in combination with therapeutic laser systems could support not only a treatment plan, but they also directly influence the process of healing and reduce inflammation. The study was carried out under clinical project No. 00064203 (FN MOTOL).

Age verification using random forests on facial 3D landmarks.

Three-dimensional facial images are becoming more and more widespread. As such images provide more information about facial morphology than 2D imagery, they show great promise for use in future forensic applications, including age estimation and verification. This paper proposes an approach using random forests, a machine learning method, to develop and test models for classification of legal age thresholds (15 years and 18 years) using 3D facial landmarks. Our approach was developed on a set of 3D facial scans from 394 Czech individuals (194 males and 200 females) aged between 10 and 25 years. The dataset was retrieved from a sizable database of Central European faces - The FIDENTIS 3D Face Database. Three main types of input variables were processed using random forests: I) shape (size-invariant) coordinates of 3D landmarks, II) size and shape coordinates of 3D landmarks, and III) inter-landmark distances, angles and indices. The performance rates for the combinations of variables and age threshold were expressed in terms of sensitivity and specificity. The overall accuracy rates varied from 71.4%-91.5% (when the male and female samples were pooled). In general, higher accuracy was achieved for the age limit of 18 years than for 15 years. Whereas size-variant variables showed a better performance rate for the age limit of 15 years, the size-invariant variables (i.e., shape variables) were better for classifying individuals under 18 years. The verification models grounded on traditional variables (distances, angles, indices) yielded consistently higher performance rates on females than on males, whereas the inverse trend was observed for the models built on 3D coordinates. The results indicate that age verification based on 3D facial data with processing by the random forests method has high potential for further forensic or biometric applications.

Comparison of 2D OPG image versus orthopantomogram from 3D CBCT from the forensic point of view.

Forensic dental identification has employed traditionally 2D digital radiological imaging techniques. More recently, 3D cone beam computer tomography (CBCT) data, widely applied in clinical dentistry, have been gradually used. The purpose of this study was to compare the precision and quality of 2D digital orthopantomogram (OPG) and 2D OPG images generated from cone beam computed tomography (CBCT). The study sample consisted of 50 patients with archived conventional 2D OPG and 3D CBCT images. Patients signed an informed consent form to take part in our study. Measurements of the mandible, teeth and dental restorations were taken by two observers on calibrated 2D OPG and 3D CBCT-to-OPG images using measurement functionalities of DOPLHIN software. Acquired dimensions were compared side by side and images of fillings were superimposed. For better visual comparison and more efficient image registration, the methods of spline interpolation were used. The pairs of absolute measurements obtained from conventional OPG and CBCT-to-OPG-converted images were highly correlated (p < 0.05). However, larger, and horizontally measured distances were revealed to be more affected than shorter vertically taken measurements. In relative terms, CBCT-generated width/length indices of the canines and the first molars ranged from 84% to 99.8% of those acquired from traditional OPGs. In addition, corresponding points on the teeth and fillings were compared side by side and in superimposition. The average coincidence of images was 6.1%. The results revealed that for selected metric variables 2D OPGs and 3D CBCT-generated OPGs were complementary and could be used for forensic comparisons.

Videofluoroscopic Swallow Study in Diagnostics of H-Type Tracheoesophageal Fistula in Children.

Esophageal atresia remains one of the most challenging congenital anomalies of the newborn. It can occur with or without tracheoesophageal fistula (TEF), and to date, there are still no universally recommended diagnostic procedures. The so-called H-type TEF is that without esophageal atresia, and its prevalence is lower than 5% of all TEFs. We present a case report of a newborn with regurgitation, vomiting, feeding problems, dyspnea, and repeated aspiration bronchopneumonia. A wide range of diagnostics procedures had been performed with negative results until we used videofluoroscopy, which revealed the H-type TEF and allowed appropriate treatment of the patient.

Association between Swallowing-Related Questionnaire Responses and Pathological Signs on Videofluoroscopy in Children.

The aim of this study was to identify relationships in children between responses to specific questions of interest in a clinical questionnaire concerning swallowing-related difficulties and pathological signs on a videofluoroscopic swallowing study (VFSS). A prospective data analysis was made of children evaluated with swallowing disorder between January 2018 and April 2021 at a tertiary care centre. Each child enrolled in the study underwent a subjective evaluation (targeted questions) and instrumental examination (VFSS). In total, 51 children suffering from swallowing problems (32 with a neurological disorder and 19 without neurological disorder) were included into the study. Our results showed there was a correlation between the occurrence of specific symptoms (wet voice, wet breathing, recurrent respiratory infections, chronic mucus) and other pathological signs on a VFSS (laryngeal penetration, residua, nasal regurgitation). The evaluation of these specific questions is a reliable and useful method for the management of dysphagia in neonates and infants. It can help us in selecting those patients for which it is appropriate to perform a VFSS.

Digital restoration of fragmentary human skeletal remains: Testing the feasibility of virtual reality.

Experts in forensic anthropology and medicine have become gradually accustomed to examining components of the human body in the virtual workspace. While the computer-assisted approach offers numerous benefits, the interactions with digital three-dimensional biological objects are often problematic, particularly if conducted with mouse, keyboard and flat-panel screen. The study focusses on feasibility of a virtual reality (VR) system for virtual restoration of fragmentary skeletal remains. The VR system was confronted with three cases of fragmentary remains. The cases were reassembled manually by twenty participants using a HTC Vive headset combined with an in-house application A.R.T. The same task was performed using a CloudCompare software in conjunction with a desktop peripheral. The two systems were compared in terms of time efficiency, the geometric properties of the resulting restorations, and convenience of use. Restoration using the VR system took approximately half the time the desktop set-up did. The VR system also yielded a lower error rate when a severely fragmented skull was reassembled. Ultimately, although the efficiency of the reassembling was shown to be strongly dependent on the operator's experience, the use of the VR system balanced out the uneven levels of proficiency in computer graphics. The current generation of virtual reality headsets has a strong potential to facilitate and improve tasks relating to the virtual restoration of fragmented skeletal remains. A VR system offers an intuitive digital working environment which is less affected by an operator's computer skills and practical understanding of the technology than the desktop systems are.

Laryngohyoid fractures in suicidal hanging: A prospective autopsy study with an updated review and critical appraisal.

Laryngohyoid fractures in hanging victims are one of the most studied and paradoxically contradictory topics in forensic pathology. According to literary sources, the incidence of laryngohyoid fractures in hanging varies significantly, from 0% to 100%. To verify the diagnostic significance of these injuries in hanging, we prospectively and consecutively analyzed the occurrence of laryngohyoid fractures in a group of 178 suicidal hanging victims (M/F=150/28, aged 14-94years, mean age=50, complete suspension=111 cases, partial suspension=67 cases) in relation to selected variables (age, sex, weight, the completeness of body suspension, and ligature knot location). Altogether, we identified the following types of laryngohyoid fractures in 129 of 178 cases (72.5%): isolated fracture(s) to the thyroid cartilage in 60 cases (33.7%), combined thyrohyoid fractures in 41 cases (23.0%), isolated fracture(s) to the hyoid bone in 28 cases (15.7%), and no fractures to the cricoid cartilage or the cervical vertebrae. The highest frequency of laryngohyoid fractures was found in lateral hangings (right lateral: 26/34, 76.5%; left lateral: 31/37, 83.8%), whereas the lowest rate was found in anterior hangings (4/11, 36.4%). In lateral hangings, fractures more often occurred contralaterally to the suspension point. Statistical analysis revealed significant associations of the occurrence of laryngohyoid fractures with the age of the victim (p=0.028), with the position of the ligature knot on the neck (p=0.019) and with the age-corrected weight of the victim (p=0.026). In addition, we performed a systematic updated review and critical appraisal of relevant literary sources to report the incidence, fracture patterns, and contributing variables of laryngohyoid injuries in hanging. Both the results of our study and the provided literary synthesis show that if evaluated properly, laryngohyoid fractures in hanging may diagnostically offer far more than just evidence that injury to the neck occurred and may also present research opportunities regarding several issues that should be further analyzed and explained.

Applying 3D prints to reconstructing postmortem craniofacial features damaged by devastating head injuries.

Postmortem facial identification is one of the most common techniques for establishing a deceased person's identity. In victims suffering from devastating cranial injuries, the feasibility of facial identification tasks can be compromised by damage to or disfigurement of the identifying cranial features. Although there are several reconstructive approaches, which help experts to restore the essence of person's physical appearance, thus enhancing the chances of recognition, only a few of them involve restoring the fractured cranial bones as the foundation for the reconstructed soft tissues. Here, we propose a technique based on replacement of heavily damaged hard tissues with generic prosthetics manufactured by 3D printing. Our approach does not require medical imaging technologies or other costly lab equipment. It is simple, affordable and relatively labor-efficient. The deceased's reconstructed craniofacial features can be subsequently assessed, photographed, drawn or otherwise reproduced in order to help determine his or her identity. In addition, the imagery can be displayed, published or broadcasted in media without concerns of being overly graphic.

Using drone-mounted cameras for on-site body documentation: 3D mapping and active survey.

Recent advances in unmanned aerial technology have substantially lowered the cost associated with aerial imagery. As a result, forensic practitioners are today presented with easy low-cost access to aerial photographs at remote locations. The present paper aims to explore boundaries in which the low-end drone technology can operate as professional crime scene equipment, and to test the prospects of aerial 3D modeling in the forensic context. The study was based on recent forensic cases of falls from height admitted for postmortem examinations. Three mock outdoor forensic scenes featuring a dummy, skeletal remains and artificial blood were constructed at an abandoned quarry and subsequently documented using a commercial DJI Phantom 2 drone equipped with a GoPro HERO 4 digital camera. In two of the experiments, the purpose was to conduct aerial and ground-view photography and to process the acquired images with a photogrammetry protocol (using Agisoft PhotoScan® 1.2.6) in order to generate 3D textured models. The third experiment tested the employment of drone-based video recordings in mapping scattered body parts. The results show that drone-based aerial photography is capable of producing high-quality images, which are appropriate for building accurate large-scale 3D models of a forensic scene. If, however, high-resolution top-down three-dimensional scene documentation featuring details on a corpse or other physical evidence is required, we recommend building a multi-resolution model by processing aerial and ground-view imagery separately. The video survey showed that using an overview recording for seeking out scattered body parts was efficient. In contrast, the less easy-to-spot evidence, such as bloodstains, was detected only after having been marked properly with crime scene equipment.

The virtual approach to the assessment of skeletal injuries in human skeletal remains of forensic importance.

While assessing skeletal injuries in human skeletal remains, forensic anthropologists are frequently presented with fractured, fragmented, or otherwise modified skeletal remains. The examination of evidence and the mechanisms of skeletal injuries often require that separate osseous elements be permanently or temporarily reassembled or reconstructed. If not dealt with properly, such reconstructions may impede accurate interpretation of the evidence. Nowadays, routine forensic examinations increasingly incorporate digital imaging technologies. As a result, a variety of PC-assisted imaging techniques, collectively referred to as the virtual approach, have been made available to treat fragmentary skeletal remains. The present study employs a 3D virtual approach to assess mechanisms of skeletal injuries, and provides an expert opinion of causative tools in three forensic cases involving human skeletal remains where integrity was compromised by multiple peri- or postmortem alterations resulting in fragmentation and/or incompleteness. Three fragmentary skulls and an incomplete set of foot bones with evidence of perimortem fractures (gunshot wounds) and sharp force trauma (saw marks) were digitized using a desktop laser scanner. The digitized skeletal elements were reassembled in the virtual workspace using functionalities incorporated in AMIRA® version 5.0 software, and simultaneously in real physical space by traditional reconstructive approaches. For this study, the original skeletal fragments were substituted by replicas built by 3D printing. Inter-method differences were quantified by mesh-based comparison after the physically reassembled elements had been re-digitized. Observed differences were further reinforced by visualizing local variations using colormaps and other advanced 3D visualization techniques. In addition, intra-operator and inter-operator error was computed. The results demonstrate that the importance of incorporating the virtual approach into the assessment of skeletal injuries increases with the complexity and state of preservation of a forensic case. While in relatively simple cases the virtual approach is a welcome extension to a traditional approach, which merely facilitates the analysis, in more complex and extensively fragmentary cases such as multiple gunshot wounds or dismemberment, the virtual approach can be a crucial step in applying the principles of gunshot wounds or sharp force traumatic mechanisms. The unrestricted manipulation with digital elements enabling limitless repairs and adjustments to a "best-case scenario" also produced smaller inter-operator variation in comparison to the traditional approach.

Passive air sampler as a tool for long-term air pollution monitoring: Part 1. Performance assessment for seasonal and spatial variations.

The potential of passive air sampling devices (polyurethane foam disks) to assess the influence of local sources on the quality of the surrounding environment was investigated. DEZA Valasske Mezirici, a coal tar and mixed tar oils processing plant, and Spolana Neratovice, a chemical factory with the history of high production of organochlorinated pesticides (OCPs), were selected as the point sources of PAHs, and OCPs, respectively. Levels of PCBs, OCPs and PAHs were determined for all sampling sites and sampling periods. The study brought useful data about the air concentrations of POPs in the investigated regions. More important, it provided information on the transport and fate of POPs in the vicinity of local sources of contamination useful for the estimation of their influence. Very good capability of passive samplers to reflect temporal and spatial fluctuation in concentrations of persistent organic pollutants in the ambient air was confirmed which makes them applicable for monitoring on the local scale.

Sex and ancestry assessment of Brazilian crania using semi-automatic mesh processing tools.

The present paper aims to test performances of semi-automatic tools for mesh-to-mesh processing while assessing sex and ancestry in documented human crania. The studied sample of 80 human crania, which originated in two documented Brazilian collections (São Paulo, Brazil) was digitized using photogrammetry and laser scanning. 3D cranial morphology was quantified by computing inter-mesh dissimilarity measures using in-house freeware FIDENTIS Analyst (www.fidentis.com). Numerical outputs were further processed using Discriminant Function Analysis and Canonical Variant Analysis in order to classify models into sex and ancestry groups. In addition, cranial morphology was described by a set of 37 landmarks, processed by a Procrustes analysis and confronted with the inter-mesh comparison. Patterns of sexual dimorphism and ancestral group-specific variation were interpreted using average meshes and further emphasized by employing advanced visualization graphics. The mesh-to-mesh processing was capable to detect shape differences related to sex and ancestry. The highest accuracy levels for sex determination were obtained for meshes representing the facial skeleton and the supraorbital region. For both, analysis correctly assigned 82.5% of the crania. Ancestry-related differences were manifested primarily in the global cranial features (observed accuracy rates reaching 63%). The advanced visualization tools provided a highly informative insight into sexual dimorphism and ancestry-related variation. While in the current state the technique cannot be considered suitable for being implemented into the everyday forensic practice, the extent of automatization proved to be perspective, especially for assessing skeletal features that cannot be properly quantified using discrete variables.