published_or_final_version / Dentistry / Master / Master of Philosophy

Akademisk avhandling--Lund. / Extra t.p., with thesis statement, inserted. Bibliography: p. 123-126.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains ix, 65 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 53-55).

Akademisk avhandling--Lund. / Extra t.p., with thesis statement, inserted. Bibliography: p. 123-126.

This work describes the investigation of a new 3D capture method for acquisition and subsequent forensic analysis of bite mark injuries on human skin. When documenting bite marks with standard 2D cameras, errors in photographic technique can occur if best practice is not followed. Subsequent forensic analysis of the mark is problematic when a 3D structure is recorded in a 2D space. A 3D image capture and processing system might avoid the problems resulting from the 2D reduction process, simplifying the guidelines and reducing errors. The proposed solutions in this work are: conducting a review of the current 2D and three 3D capture methods, also a series of benchmarks for system assessment. Followed by a series of performance evaluations of the existing current 2D and two 3D methods. Further proposed solutions include, the design of a system specification for the practical reproducible acquisition of bite mark injuries. Finally a review of the validation process for forensic evidence presented to the courts. The results of the work are as follows: A 3D system is required to produce the correct 3D data of a bite mark and suspect dentition for forensic analysis. Such a system should be practical and consistent, if it is to replace the current de facto 2D systems. The MAVIS hardware can be considered a practical and consistent solution for producing the required 3D image of a bite mark for analysis; however, the MAVIS hardware cannot produce a satisfactory 3D image of a dental cast. At present a laser scanner is required to produce satisfactory results of a dental cast. Angular distortion and errors created by the user in 2D image capture can hinder the digital measurement process. 3D capture therefore introduces less operator error in the form of angular distortion.

Thesis (M.A.)--University of Montana, 2008. / Title from title screen. Description based on contents viewed Aug. 28, 2008. Includes bibliographical references (p. 80-93).

With the evolution of forensic technology, methods for positive identification are vast and accurate. These methods allow for a corpse to be identified at almost any point of decomposition. The new technology and new methodology has led to a more creative and resourceful criminal. Although few cases have been documented where chemicals are the mode of disposal, this method provides a seemingly fool proof and effective approach to disposal. Several household chemicals contain harmful agents that when used may result in the masking of identity. The purpose of this study is to indicate which chemicals can be used in order to erode or dissolve the tissues making up the dentition and bone. Four chemicals, potassium hydroxide, sodium hydroxide, muriatic acid (hydrochloric acid) and sulfuric acid were chosen and tested on teeth and bone. The dentition and bone were exposed for a period of eight hours. Measurements including mass and caliper measurements were obtained at two-hour intervals. Of the common chemicals tested, muriatic acid (hydrochloric acid) was the most effective for destroying the tissues.

Thesis (MSc (Radiography))--Cape Peninsula University of Technology, 2018. / Introduction: Forensic dentistry plays a key role in identifying human remains that cannot be identified visually or by other means. Studies have shown that in cases of single or multiple deaths, scientific identification of human remains utilising forensic dentistry is often the most successful source of identification. Dental identification of human remains consists of a very complex procedure that makes it necessary during the investigation process to use and compare unique dental identifiers. A reliable and accurate method of identifying human remains is a positive radiological identification between ante-mortem and post-mortem images of dental radiographic images. Even if ante-mortem radiographic images may not be present during the identification process, post-mortem images may include details of dental restorations such as dental implants which cannot be seen during visual examination. The different types of dental implants vary in morphology and in conjunction with the unique appearance of dental anatomy and the placement of custom restorations such as dental implants, it has been found to accurately assist in the identification of human remains. Objectives: To establish a radiographic dental implant guide for ten commonly used dental implant types in the Western Cape, South Africa; and to identify and describe the morphological characteristics of these dental implant types as observed on pantomographs. Methods: The ten commonly used dental implant types were imaged radiographically to create a reference instrument which served as a tool for identifying and comparing different types of dental implants. The morphologies of the different dental implants, specifically the apex, thread and neck, were observed on ante-mortem pantomographs and compared to the appearance of the dental implants on the reference instrument to make a positive match. The straight tube image of all ten dental implant types in the reference instrument was used as the point of reference to positively identify the morphological characteristics of each dental implant type on the pantomographs. The morphological characteristics of the ten commonly used dental implant types used in the Western Cape were described and based on this a radiographic dental implant guide was developed. Results: A total of 384 dental implants were observed on the pantomographs. Of these, 380 dental implants could be positively identified on the pantomographs while 4 dental implants could not. A total of 350 dental implants (91%) were identified as dental implant types listed in the reference instrument while 30 dental implants were identified as a dental implant type not listed in the reference instrument. A total of 208 dental implants (54.2%) could be positively identified using the morphological characteristics namely the apex, thread and neck on the straight tube images of the dental implant type in the reference instrument. The radiographic dental implant guide was developed based on positive identification of the morphological characteristics of the dental implant types. Conclusion: This research study has illustrated that the morphology of dental implants can be used to differentiate between different dental implant types on pantomographs. Each dental implant type had unique morphological characteristics as well as similarities which enabled distinction between the different dental implant types, which facilitated dental implant identification and the development of a radiographic dental implant guide. The radiographic dental implant guide developed as part of this research study, may be useful in the field of forensic dentistry and forensic radiology.

Orientador: Horácio Faig Leite / Banca: Michelle Cardoso de Sousa / Banca: Luiz Eduardo Blumer Rosa / Resumo: Sabe-se que o processo mastoide (PM) tem sido utilizado como uma característica diferencial entre crânios de espécies diferentes e mesmo entre os sexos. Muitos são os métodos utilizados para se diferenciar os processos mastoides masculinos dos femininos. Tal diferenciação é muito importante na antropologia física e na forense. Neste trabalho foi utilizada a metodologia empregada por Hoshi (1962) na qual classifica os PM segundo a sua curvatura. O objetivo deste trabalho foi verificar a aplicabilidade desta metodologia. Foram utilizados 305 crânios humanos identificados segundo o sexo, grupo étnico e idade, pertencentes ao Museu de Crânios da Disciplina de Anatomia Descriptiva e Topográfica da Escola Paulista de Medicina - UNIFESP. Os resultados obtidos foram submetidos à análise estatística (análise descritiva e teste quiquadrado) e constatou-se que as inclinações do tipo M (70,87%) são estatisticamente típicas do sexo masculino, enquanto as inclinações do tipo N (47,47%) e F (36,36%) são encontradas nos crânios femininos, sendo suas incidências estatisticamente significativas, demonstrando que as inclinações dos tipos N e F caracterizam, na amostra em questão, os crânios femininos. Os resultados alcançados demonstraram que o método desenvolvido por Hoshi é aplicável e de fácil execução / Abstract: It is known that the mastoid process (PM) has been used as a differential feature among skulls of different species and even between the sexes. Many are the methods used to differentiate the male mastoids from the female ones. Such a difference is very important in physical anthropology and forensics. In this work we use the methodology used by Hoshi (1962) in which it classifies PM according to its curvature. The objective of this work was to verify the applicability of this methodology. 305 skulls were used, identified by sex, ethnic group and age, belonging to the Museum of Skulls of the Discipline of Anatomy at the Paulista School of Medicine - UNIFESP. The results obtained were submitted to statistical analysis (descriptive analysis and chi-square test) and it was verified that the M-type inclinations (70.87%) are statistically typical of the male sex, while the N-type inclinations (47.47%) and F (36.36% ) are found in female skulls, and their incidence is statistically significant, demonstrating that the N and F inclinations characterize female skulls in the sample. The results showed that the method developed by Hoshi is applicable and easy to implement / Mestre

The teeth are amongst the most resilient elements of the human skeleton and are thus often utilised in routine forensic investigation involving the identification of unknown remains. The teeth, however, also have other practical forensic applications. Teeth exposed to thermal stress have the potential to not only aid in identification but also in understanding the circumstances surrounding the fire. Previous investigations have drawn conclusions that if a fire flares up suddenly and intensively, the teeth burst and enamel is lost. If the blaze commences gently and burns slowly, then the first observable morphologic change is the colour. The teeth subsequently are difficult to handle, thus changes in teeth can indicate the history of exposure to thermal conditions. Children are twice as likely to become victims of house fire because of an inability to safely evacuate from areas of danger. The literature demonstrates, however, that research on the effects of incineration on teeth is mostly restricted to the permanent teeth. The apparent lack of knowledge on the effects of incineration on deciduous teeth thus necessitates further research in this area. This research project primarily aims at understanding the effect of extreme temperatures on deciduous teeth. It also aims to relate colour changes that occur post heating with fragility to aid in proper handling of samples in a forensic scenario and to determine the possibility of identifying incineration temperature based on tooth condition. The samples analysed composed of 90 deciduous teeth (45 molars and 45 anteriors) extracted as a part of clinical treatment were used for the study. The project involved exposing extracted deciduous teeth to temperatures ranging from 100°C to 1100°C for 30 minutes using a laboratory Gallenkamp oven. Unheated deciduous teeth were used as controls for the project. Post-incineration the teeth were then analysed under a stereomicroscope and SEM for morphological changes. A colorimetric analysis was also undertaken to evaluate the colour changes induced in the primary teeth due to the thermal stress. It was found that it was possible to identify the incineration temperature based on the tooth condition when the colour changes, stereomicroscopic findings and SEM images were utilised collectively. It was also concluded that the thermally induced changes observed in primary teeth occur at lower temperatures in comparison to the permanent teeth. It was also established that post-incineration deciduous teeth are fragile and show a tendency to fragment after minimal exposure to thermal stress as compared to the permanent teeth. Moreover enamel and dentin remained identifiable in primary teeth even after exposure to 1100°C for 30 minutes while cementum lost its structural morphology at 900°C.