Computed Tomography versus Optical Scanning: A Comparison of Different Methods of 3D Data Acquisition for Tooth Replication.

OBJECTIVES: The study aimed to compare the accuracy of different methods of data acquisition and data reconstruction and to assess their usefulness for 3D printing of tooth replicas. METHODS: 3-dimensional models of molar and canine teeth obtain utilizing CBCT examination with different protocols, and optical scanning was compared with models derived from micro-computed (micro-CT) examination using Geomagic Studio Qualify software. A pairwise comparison of 3D models with analysis of standard deviation and the value of the mean distance of given surfaces was performed. RESULTS: Standard deviation and the value of the mean distance were lowest for optical scanning followed by CBC in high and standard resolution in all tested protocols. Models, obtained with high-resolution CBCT protocols, of teeth in and outside of alveolar bone showed similar average distance parameters, but standard deviation parameter was significantly lower for models of teeth scanned outside of the socket. Good surface representation on all models was seen at relatively smooth areas while in areas of high changes in the geometry CBCT based models performed inferiorly to those obtained from an optical scanner. CONCLUSIONS: In case of teeth of noncomplicated texture, independently from a position (within or outside the alveolar socket), the high-resolution CBCT seems to be a sufficient method to obtain data for 3D printed tooth replica. Optical scanning performs better when a detailed replica is necessary.

Introducing a simple method of maxillary sinus volume assessment based on linear dimensions.

Measuring sinus volume in a general practice clinic is a complex and time-consuming procedure, requiring experience in the use of radiological methods In the presented research, the automatically estimated maxillary sinus volume was compared with maxillary sinus volume assessed with mathematical formulas used to calculate the volume of spheres and pyramids. The starting point for the statistical analysis were specific measurements of the sinuses. We wanted to discover which geometric shape has the volume that is nearest to the automatically estimated volume. The study was performed using samples of CT scans of pediatric patients age 1-17. The dimensions (maximal width, maximal height, maximal length) were used for manual calculations. For the automatic volume calculation, the CT Image Segmentation algorithm (Syngo Via for Oncology, Siemens) was used. Pearson's correlation coefficient was applied to analyse the interrelationship between automatically and manually calculated volume of maxillary sinus. It was statistically established that the "sphere", "pyramid" and "mean" manually calculated maxillary sinus volume were accurate and strongly correlated with the automatically estimated maxillary sinus volume. The volume of the sphere corresponds better with the automatic measurements than the volume of the pyramid. The variations are significant and they were made reliable with the application of a statistical test. It is quick and easy to calculate the maxillary sinus volume based on its linear dimensions instead of applying advanced software. The manual method for maxillary sinus volume calculation requires three linear measurements of the sinus (length, width, and height) and can be recommended if the automatically estimated volume cannot be obtained.

Analysis of human dentition from Early Bronze Age: 4000-year-old puzzle.

This paper presents the first ever paleodontological investigation of human remains from an archeological site in Central Europe dating from the Early Bronze Age and attributed to the Strzyzow Culture. It corroborates the knowledge gained from archeological, anthropological and genetical investigations. Our study aimed to assess dental status, dental morphology and dental pathologies as well as tooth wear and enamel hypoplasia based on visual inspection and stereomicroscopic investigation. The research was supported by CBCT imaging to obtain digital images and 3D reconstructions as well as 2D radiographs essential for dental age estimation. All of the 191 teeth discovered showed morphological similarity, with adult teeth showing similar color, shape and size. A maxillary molar presenting with a unique root morphology and a mandibular molar with a rare occlusal surface were found. Both permanent and deciduous dentition presented significant tooth wear. A few specimens displayed signs of dental caries, periapical pathology and antemortem tooth loss. Three individuals exhibited linear enamel hypoplasia. CBCT provided high-quality 2D images useful for dental age estimation by non-destructive methods. Estimated dental age correlated with the age estimated by other anthropological methods. In one case, this was crucial because of insufficient material for anthropological analysis. The presented studies have proved that besides the skeleton, teeth can be used as a fundamental tool in assessing the overall health and living conditions of paleopopulations. It would seem that there is potential for considerable development to be made in the research and investigation of paleodontological material using CBCT.

Accuracy of the anthropometric measurements of skeletonized skulls with corresponding measurements of their 3D reconstructions obtained by CT scanning.

BACKGROUND: The anthropometric measurements of the skeletonized skull are crucial in the investigation of human remains, mostly for personal identification. The images of the skull are used if the superimposition or approximation of the facial appearance is to be performed. The aim of the study was to compare the accuracy of the anthropometric measurements of skeletonized skulls with corresponding measurements of their 3D reconstructions obtained by CT scanning. METHODS: Ten skeletonized skulls and their 3D digital reconstructions were measured according to standard anthropometric procedures. The results were compared and statistical analysis was performed. RESULTS: The statistical analysis revealed that the 3D reconstruction is absolutely reliable for any measurements within the skull. The results of the measurements obtained from the CT image were accurate and comparable to the results of the anthropometric analysis of the skeletonized skull. The correlation between the anthropometry of the skeletonized skulls and the CT reconstructions was strong. CONCLUSIONS: It is relevant that 3D reconstructions of the skull can be used in forensic anthropology for personal identification.

Development of the maxillary sinus from birth to age 18. Postnatal growth pattern.

OBJECTIVES: Anatomical and developmental descriptions of the maxillary sinus may be of great clinical importance. An understanding of age-related changes in the dimensions and volume of the normal maxillary sinus may help in the evaluation of radiographs and identification of sinus abnormalities. The aim of the present study was to define growth patterns of maxillary sinuses in children up to the age of 18 years and evaluate the correlation between normal age-related changes in dimensions and volume. METHODS: The research sample consisted of CT scans of 170 patients subdivided into 17 groups based on age. Normal developmental changes were investigated and linear dimensions measured. RESULTS: The maxillary sinus, present at birth, increases in size until the end of the 18th year. The growth pattern includes changes in vertical, horizontal and antero-posterior directions. No bilateral dimorphism was observed, but gender-related differences were found in children over the age of 8 years. The most extensive period of growth occurs during the first 8 years and by the end of the 16th year the maximal values of all diameters and volume are reached. CONCLUSIONS: A CT study of developing maxillary sinuses allowed a precise evaluation of age-related changes in all diameters and volume to be made.

Difficulties in personal identification caused by unreliable dental records.

This paper demonstrates a case of personal identification that initially seemed straightforward, mainly because complete and comprehensive antemortem dental records of a missing person were made available for analysis. Skeletal remains were found and the skull (most crucial for human identification) was delivered for analysis. Comparative analysis of antemortem and postmortem dental records excluded identification, while the results of superimposition (simultaneously performed by another team member) revealed sufficient concordant points to establish identity. The results caused confusion and additional information was required. The need for more evidence resulted in delivery of elements of the postcranial skeleton. Identification was finally achieved when concordant points were established in a comparison of antemortem X-rays and the humerus. Team members concluded that the dental records were in fact not adequate and that mistakes in numbering the teeth (superior canine instead inferior canine and right and left premolars) were considered to be the initial reason a positive identification had not been made. The authors conclude that a multidisciplinary approach is crucial to making a positive identification and that caution should be exercised when carrying out personal identification from dental records alone. The need to adequately train police officers to collect and preserve dental evidence is also emphasized.

Body mass estimation in modern population using anthropometric measurements from computed tomography.

Forensic anthropologists are able to estimate the stature of a skeleton, its sex and biological age at death, with a relatively high degree of accuracy. Body mass estimation from the stature and bi-iliac (maximum pelvic) breadth and femoral head breadth can be useful in forensic investigations involving unidentified skeletal remains. Predicting the body mass of skeletal remains always involves significant inaccuracy, however when body mass extremes are disregarded average figures provide the best estimation. The aim of the study was to investigate whether the methods usually used in body mass estimation are accurate in different BMI ranges. The usefulness of these methods in forensic anthropology was discussed. The study was performed using CT images of widely differing body types of modern central European populations. Maximum pelvic breadth and anteroposterior femoral head breadth were measured directly from the appropriate CT scan slices for each individual. Body mass index was established for each individual. Four different methods of body mass estimation were applied. The statistical analysis showed that body mass prediction methods based on the bi-iliac breadth with known stature and the femoral head breadth show strong correspondence. The results of body mass estimation using different methods were in high correlation with normal BMI. The accuracy of body mass prediction of underweight and obesity cases (BMI extremes) showed significant inaccuracy. Body mass estimation methods can provide important information for forensic anthropological investigation and personal identification. However, one should be aware of the discrepancies and should apply the equations carefully as they can carry significant errors.

[Sexual offences--selected cases]. / Przestepstwa seksualne--wybrane przypadki.

INTRODUCTION: Expert testimony on violence victims also includes victims of sexual assault. The role of an expert is to classify the injuries by their severity as defined in art. 157 156 or 217 of the Criminal Code pertaining to crimes against health and life. Also, the role of an expert opinion is to determine whether the injuries identified during the exam occurred at the time and under the circumstances stated in medical history. The examination of sexual assault victims is conducted by two experts: a gynecologist and a forensic physician. Most examinations are performed at different times and various medical centers. The conclusions are presented in an official report. Regardless of victim age, all sexual crimes are investigated ex officio by the Police Department and the Prosecutor's Office. Further legal classification of criminal offenses is the task of an appropriate legal body and the offenses are codified in accordance with the provisions of chapter XXV of the Criminal Code, articles 197 - 205. In controversial cases, i.e. when two different expert opinions appear on the same case, or if, according to the law enforcement, a medical opinion is insufficient for some reason, an appropriate expert or team of experts is appointed to resolve the problem. OBJECTIVES: To present selected cases of sexual violence victims treated at the Department of Gynecology and assessed at the Department of Forensic Medicine with reference to the challenges regarding qualification of the sustained injuries and clinical diagnoses. MATERIAL AND METHODS: Research material included selected forensic opinions developed for law enforcement offices that involved victims of sexual violence. The expert opinions were prepared either on the basis of submitted evidence, or both, submitted evidence and examination of the victim at the Department of Forensic Medicine. Moreover the article presents a case of a patient examined and treated at the Department of Gynecology in Poznan. CONCLUSIONS: Based on the selected cases, the authors conclude that a medico-legal expert cannot uncritically accept previous diagnoses. Moreover every expert is given the right and obligation to verify them. The need for complete, rapid and almost simultaneous colaboration between physicians in charge of the case, forensic doctors, police officers and prosecutors was demonstrated. Lack of cooperation may give rise to different opinions, leading to unnecessary elongation of the medico-legal procedures. It was observed that time plays a crucial role if qualification of an injury is required. The obligation of medical staff to inform the law enforcement about all cases of child abuse was also emphasized.

Injuries due to human and animal aggression in humans.

INTRODUCTION: People breed animals, professionally take care of them, and work with them. To live with animals, however, it is necessary to know their behaviour and habits, as well as fears. Ignorance of this knowledge may lead to tragedy for the victim (a person), as well as for the beast (animal). Then, nobody cares whether the animal behaved itself or not in accordance with its nature. OBJECTIVE: The aim of the presented study is to compare the rate of animal aggression in relation to cases of documented aggression towards humans. The victims were investigated according to the age, gender and types of injuries caused by animal bites. MATERIAL AND METHODS: The protocols of autopsies (2,218) and medical-legal examinations (4,569) performed from 2004-2009 in the Department of Forensic Sciences in Poznan were analyzed. The selected data was studied using Microsoft Office Excel 2007 for Windows. RESULTS: Analysis revealed the presence of animal bite injuries in less than 1% of the deceased victims of aggression. The number of individuals who died as a result of animal bites varied from 1-4 a year, and in all cases these were postmortem injuries. Analysis of injuries among surviving victims of aggression showed animal bite injuries were present in 41 out of 4,569 victims, almost equally among males and females. Moreover, in 25 victims the bite injuries recognized as human were found. The majority of animal bites occurred in adults. The medium injuries were the most frequent in the animal bite victims. CONCLUSIONS: Animal aggression is a marginal problem considering all cases of aggression towards humans. In contrast to the aggression of humans towards other humans, this is a very rare cause of human death or even major injury.

The conclusive role of postmortem computed tomography (CT) of the skull and computer-assisted superimposition in identification of an unknown body.

Computed tomography is commonly used in modern medicine, and thus, it is often helpful for medicolegal purposes, especially as part of the antemortem record. The application of postmortem computed tomography and 3D reconstruction of the skull in challenging cases is reported, and its valuable contribution to positive identification is discussed. This paper presents a case in which the body of an unknown individual is identified. Positive identification had not been possible despite a multidisciplinary examination. The postmortem use of computerized tomography and 3D reconstruction of the skull followed by the comparison of individual morphological characteristics of the viscerocranium showed the concordant points between the deceased and a missing person. Finally, superimposition using a 3D-reconstructed skull instead of the skeletonized skull demonstrated an adequate degree of morphological consistency in the facial images of the analyzed individuals that lead to positive identification. It was concluded that where other methods of personal identification had failed, the use of postmortem computed tomography had proved to be instrumental in the positive identification of the deceased.

Causes of problems in multidisciplinary bitemark analysis / Przyczyny trudnosci interdyscyplinarnej analizy sladów ugryzien.

Since a successful bitemark analysis depends on many factors, it is important that the phases preceding the analysis be carried out as thoroughly as possible. Interpretive errors in the analysis arise primarily from the complex nature of bitemarks, but also as a result of faulty research methodology, false assumptions or technical errors made during the identification and documentation process. The key role is played by qualifications, knowledge and experience of experts involved in the investigations. In case bitemarks are detected, it is recommended to seek consultations by forensic odontologists or members of an interdisciplinary team experienced in bitemark analysis. The thus obtained information allows for gathering evidence guaranteeing a reliable expert opinion.

[Comparison of bite marks and teeth features using 2D and 3D methods]. / Analiza porównawcza sladów zebów i cech zebów z wykorzystaniem metod 2D i 3D.

UNLABELLED: The nature of bite marks is complex. They are found at the scene of crime on different materials and surfaces - not only on human body and corpse, but also on food products and material objects. Human bites on skin are sometimes difficult to interpret and to analyze because of the specific character of skin--elastic and distortable--and because different areas of human body have different surfaces and curvatures. A bite mark left at the scene of crime can be a highly helpful way to lead investigators to criminals. The study was performed to establish: 1) whether bite marks exhibit variations in the accuracy of impressions on different materials, 2) whether it is possible to use the 3D method in the process of identifying an individual based on the comparison of bite marks revealed at the scene, and 3D scans of dental casts, 3) whether application of the 3D method allows for elimination of secondary photographic distortion of bite marks. The authors carried out experiments on simulated cases. Five volunteers bit various materials with different surfaces. Experimental bite marks were collected with emphasis on differentiations of materials. Subsequently, dental impressions were taken from five volunteers in order to prepare five sets of dental casts (the maxilla and mandible. The biting edges of teeth were impressed in wax to create an imprint. The samples of dental casts, corresponding wax bite impressions and bite marks from different materials were scanned with 2D and 3D scanners and photographs were taken. All of these were examined in detail and then compared using different methods (2D and 3D). RESULT: 1) Bite marks exhibit variations in accuracy of impression on different materials. The most legible reproduction of bite marks was seen on cheese. 2) In comparison of bite marks, the 3D method and 3D scans of dental casts are highly accurate. 3) The 3D method helps to eliminate secondary photographic distortion of bite marks.

[Problems associated with age estimation of underage persons who appear in child pornography materials]. / Problemy oceny wieku osób maloletnich w sprawach dotyczacych ich wykorzystania w pornografii dzieciecej.

UNLABELLED: Among opinions issued by the Forensic Medicine Department, Medical Science University in Poznan, in the last six years, there are opinions concerning age estimation in child pornography materials. The issue subject to research is indicating persons under the age of 15 years in pornographic materials, since possession of pornographic materials featuring underage persons is considered a crime and is subject to article 202 of the Penal Code. The estimation of the age of teenagers based on secondary and tertiary sexual characteristics is increasingly more difficult and the available data in professional literature regarding the standard time of development differ among various authors of such studies. In the report, an attempt has been made at determining the agreement regarding different characteristics in the data included in the Tanner's scale, which has been modified to accommodate the research done on persons registered by electronic means. The modified scale, which up to now has been used in research of registered subjects in classified public prosecutors' materials, has been employed in children seen in a pediatric outpatient department. The goal has been a comparison of the outcome of the research to prove its usefulness so that in the future, the modified scale could be used as a research tool in estimation of age of persons appearing in pornography materials. MATERIAL AND METHOD: medical forms of 205 children seen in a pediatric outpatient department, based on the scale created by the present authors us and later processed using Excel.

[Fatal injuries of organs situated in the neck caused by fastened seat belts]. / Obrazenia smiertelne narzadów szyi spowodowane zapietymi pasami bezpieczenstwa.

The authors present the type and extent of injuries inflicted as a result of the victims wearing fastened seat belts during frontal impacts of the vehicles. As an example of a particular traffic accident, the authors describe a rare case of neck injuries resulting from improper fitting of the safety belt to the victim's height. The driver of the car that had frontally hit the obstacle was killed on the spot, while the female passenger, was taken to hospital in a severe condition, where she died several hours later. The direct cause of death of the passenger were injuries of the organs situated in the neck, such as rupture larynx, epiglottis and the thyroid cartilage, as well as the hyoid bone fracture resulting from an impact with a fastened safety belt.

[DNA studies performed on a mummified body from Forensic Department Museum of Poznan University of Medical Sciences]. / Badania DNA zmumifikowanych zwlok z muzeum Katedry i Zakladu Medycyny Sadowej Uniwersytetu Medycznego im. Karola Marcinkowskiego w Poznaniu.

The article presents the results of experimental DNA examinations of a mummified body, which is kept in the Forensic Department Museum of Poznan University of Medical Sciences. The DNA analysis determined the gender of the mummy as male; the body was found to belong to the Y-chromosome haplogroups R1b and J2. The age of the mummified body was estimated by an anthropological examination as approximately 35 years.

[Identification of a murderer on the basis of a biting pattern on body of the victim]. / Identyfikacja sprawcy zabójstwa na podstawie sladów zebów na ciele ofiary.

The authors present a case of identification of a a murderer on the basis of his dentition pattern, reflected by a biting wound on the breast of the victim. The case is exceptional not only from the viewpoint of the authors, but also in view of very sporadic reports on this subject in forensic literature. Cases of biting by humans are not frequent in the forensic/ medical practice, and instances of identification of the perpetrator by his dental pattern reflected in the biting wound are very rare. In Poland, such problems have been the domain of mainly criminologists and only occasionally of forensic medics in collaboration with dentists and anthropologists. Due to the very low number of such cases in Poland, no experts in the matter are available. For this reason, we deemed it purposeful to present respective investigative principles and techniques for identification of a human perpetrator on the basis of the dental pattern reflected in a biting wound on the victim's body.

[Deaths in the sobering station in Poznan]. / Zgony w izbie wytrzezwien w Poznaniu.

Post mortem examination protocols of the Chair and Department of Forensic Medicine, University of Medical Sciences in Poznan, pertaining to deaths occurring in the Sobering Station in Poznan in the years 1956-2008 were selected. In the analyzed period, 117 such cases were identified, what constituted approximately 2 deaths per annum. The majority of deaths occurred in males; women constituted a small percentage of all the cases. Over 3/4 of deaths were seen in patients between 26 and 50 years of life. Acute alcohol intoxication, acute respiratory and circulatory failure and cerebrocranial injuries constituted the main causes of death. Moreover, in few cases, the detained person committed suicide by hanging. Only in a few situations had the deceased patients been previously examined by a doctor in a hospital, but had been refused admission and had been referred to a sobering station. The results show that over 3/4 of deaths in the Poznan Sobering Station was a consequence of misdiagnosis, most frequently concerning unrecognized acute alcohol intoxication, cerebrocranial injuries or acute myocardial infarction. A change of regulations concerning the functioning of sobering stations involving introduction of breathanalyzers for testing blood alcohol levels and implementation of other tests did not result in a decreased number of deaths in sobering stations due to acute alcohol intoxication.

[Examination of the skull of Stanislaw Papczynski (1631-1701)--the founder of the fraternity of Marian Priests]. / Badania czaszki Stanislawa Papczyniskiego (1631-1701)--zalozyciela zgromadzenia ksiezy Marianów.

Procedures of identifying an individual on the basis of skeletal remains are of interest to anthropologists, anatomists, morphologists, physicians and criminologists. The results of such procedures are immensely significant, both from the cognitive point of view, as they allow for determining the range of variability of human traits, and from the practical standpoint, in forensic-medical procedures. The methodical aspect of the procedures represents an important problem since the reliability of the employed identification techniques determines the probability with which we can reconstruct the intravital appearance of an individual. The theoretical grounds for the criteria used for person's identification on the basis of skeletal remains are provided by the results of studies on variability of anatomic and morphologic structures and on reciprocal relations between the soft tissues and bony sublayer on which the soft tissues are distributed. Following the process of exhumation on February 12, 2007, in March, we received the skull of Father Stanislaw Papczynski, the founder of the fraternity of Marian Priests, with the objective of performing an anthropological examination and reconstructing his face. The examinations were commissioned in association with the ceremony of his beatification planned for September 2007. We used the "POL-SIT Rekonstrukcja" computer-assisted system of intravital face reconstruction, which represents a universal human face reconstruction system, based on the skull pattern introduced to the computer. Computed tomography CT was performed employing a Siemens tomograph Somatom Sensation 64. The 3 D reconstruction of the skull was achieved using the "In Space" software.

[Difficulties in identification of human corpses and skeletal remains on the basis of dental records and examinations]. / Trudnosci identyfikacji zwlok i szczatków ludzkich w oparciu o dokumentacje i badania stomatologiczne.

The entire skull-based complex comparative identification procedure consists of several detailed studies from different disciplines of science. The range of the performed studies predominantly depends on the available and collected comparative material pertaining to the examined individual and the final outcome of the complex identification procedure represents the results of individual stages of the studies. Odontological tests involving the comparison of dentition in the examined human skull with the dentition of the typed person, established by the available comparative material, represent a significant element of the identification procedure. The aim of the investigations was the examination of availability and usefulness of dental records during the identification process. The research was based on expert opinions issued in human-skull based identification processes and performed at Department of Forensic Medicine, University of Medical Sciences in Poznan, in the period between 1996 and 2005. A total of 398 identification procedures carried out in 348 sculls was analyzed. The research was mainly identification of an individual through face reconstruction and a skull/photo comparison. An overall number of 206 computer (digital) face-reconstructions and 263 comparison analyses was done in the above-mentioned period. Statistically, in only 22 cases out of 263 comparison analyses some dental records were available. Even then, dental records were not always relevant. In 4 cases, dental records were either incomplete, inaccurate or unreadable.

[The issue of expert opinions in underage pornography materials involving underage persons below 15 years of age]. / Zagadnienie opiniowania w sprawach dotyczacych tresci pornograficznych z udzialem osób maloletnich ponizej 15. roku zycia.

The number of cases in which the estimation of age of the persons pictured in pornography materials is mandatory has been increasing for the last few years. The aim of the publication was to indicate the possibilities which are currently available for the forensic experts in this matter. The ones published heretofore mainly had focused on the difficulties which are inseparable elements of such expertise. Current publication has a demonstrative character and has been based upon the experience of two Forensic Medicine Departments. Such expertise have been constantly prepared in both of them for the last few years and none of them had to be changed till now. The currently available methods which allow for age estimation of the persons upon their photographical and movie images are far from perfection. Still authors remain skeptic about the possibility that significant progress in that matter can be achieved in predictable future. In such situation the most effective application of existing techniques becomes essential to minimize the risk of false-positive and false-negative results from appearing. Some of the difficulties pointed out by other authors are not important in practice.