165 research outputs found

    Machine Learning in Dentistry: A Scoping Review

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    Machine learning (ML) is being increasingly employed in dental research and application. We aimed to systematically compile studies using ML in dentistry and assess their methodological quality, including the risk of bias and reporting standards. We evaluated studies employing ML in dentistry published from 1 January 2015 to 31 May 2021 on MEDLINE, IEEE Xplore, and arXiv. We assessed publication trends and the distribution of ML tasks (classification, object detection, semantic segmentation, instance segmentation, and generation) in different clinical fields. We appraised the risk of bias and adherence to reporting standards, using the QUADAS-2 and TRIPOD checklists, respectively. Out of 183 identified studies, 168 were included, focusing on various ML tasks and employing a broad range of ML models, input data, data sources, strategies to generate reference tests, and performance metrics. Classification tasks were most common. Forty-two different metrics were used to evaluate model performances, with accuracy, sensitivity, precision, and intersection-over-union being the most common. We observed considerable risk of bias and moderate adherence to reporting standards which hampers replication of results. A minimum (core) set of outcome and outcome metrics is necessary to facilitate comparisons across studies

    2023/2024 University of the Pacific San Francisco Catalog

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    Climate-Related Adaptations in the Human Skull: A Review of the Different Contemporary Theoretical Models and Methods

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    Questions regarding our ancestral species have always appealed to our curious side. Our first ancestral species lived in arboreal settings before gradually adapting to a more open, terrestrial environment. It can be observed in the fossil record that hominins began to show a greater degree of adaptations towards anatomical traits that would be beneficial in such environments. Significant changes can be seen as hominins migrated out of Africa and were subsequently exposed to different climates and ecological niches. Accordingly, gaining further knowledge about these climate-related adaptations is of prime interest for understanding the context from which our ancestors emerged and evolved. However, to understand these events it is important to develop useful theoretical frameworks which can aid researchers in tying such links between human morphological variation and climate. Theoretical frameworks are used to make sense of data and more focus must be on developing such frameworks. The conclusion of this thesis is that there are only two theoretical frameworks that can be useful to climate adaptation research: modern evolutionary theory and the ecological rules of Bergmann and Allen. However, more in-depth theoretical models are needed to bridge the gap between morphological variation and climate. This study will present theoretical models and methods, compare and discuss these theoretical frameworks and methodologies, and investigate any consistencies in the use of theories within the field. This thesis also aims to critically analyse and highlight the limitations of the discipline by addressing present issues. The final aim and purpose of this thesis is to better understand the need and significance of well-built theoretical frameworks and methods in achieving a better understanding of the links between climate and morphological variation.Arkeologi mastergradsoppgaveARK350MAHF-AR

    Virtual Anthropology: forensic applications to cranial skeletal remains from the Spanish Civil War

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    Biological and forensic anthropologists face limitations while studying skeletal remains altered by taphonomic alterations and perimortem trauma, such as in remains from the Spanish Civil War. However, virtual anthropology techniques can optimize the information inferred from fragmented and deformed remains by generating and restoring three-dimensional bone models. We applied a low-cost 3D modelling methodology based on photogrammetry to develop novel forensic applications of virtual 3D skull reconstruction, assembly, restoration and ancestry estimation. Crania and mandible fragments from five Spanish Civil War victims were reconstructed with high accuracy, and only one cranium could not be assembled due to extensive bone loss. Virtual mirroring successfully restored reconstructed crania, producing 3D models with reduced deformation and perimortem trauma. High correlation between traditional and virtual craniofacial measurements confirmed that 3D models are suitable for forensic applications. Craniometric databases of world-wide and Spanish populations were used to assess the potential of discriminant analysis to estimate population ancestry. Our protocol correctly estimated the continental origin of 86.7 % of 15 crania of known origin, and despite low morphological differentiation within European populations, correctly identified 54.5 % as Spanish and 27.3 % of them with high posterior probabilities. Two restored crania from the Civil War were estimated as Spanish, and one as a non-Spanish European. Results were not conclusive for one cranium and did not confirm previous archeological hypotheses. Overall, our research shows the potential to assess the presence of foreign volunteers in the Spanish Civil War and highlights the added value of 3D-virtual techniques in forensic anthropology

    Recent Advances in Forensic Anthropological Methods and Research

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    Forensic anthropology, while still relatively in its infancy compared to other forensic science disciplines, adopts a wide array of methods from many disciplines for human skeletal identification in medico-legal and humanitarian contexts. The human skeleton is a dynamic tissue that can withstand the ravages of time given the right environment and may be the only remaining evidence left in a forensic case whether a week or decades old. Improved understanding of the intrinsic and extrinsic factors that modulate skeletal tissues allows researchers and practitioners to improve the accuracy and precision of identification methods ranging from establishing a biological profile such as estimating age-at-death, and population affinity, estimating time-since-death, using isotopes for geolocation of unidentified decedents, radiology for personal identification, histology to assess a live birth, to assessing traumatic injuries and so much more

    The Effects of Aging and Tooth Loss to the Microstructure of the Mandible in South Africans

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    Thesis (PhD (Anatomy))--University of Pretoria, 2022.The mandible plays a crucial role in many biological functions (especially mastication, swallowing and speech) and its efficiency to perform these functions depends on its intactness. Aging and tooth loss are biological processes that may compromise the normal functioning of the mandible by changing its morphology. While many studies address the macroscopic mandibular variations, there is a paucity regarding its microstructure. The aim was to investigate microstructural mandibular changes, with reference to the macrostructure, with advancing age and across various tooth loss patterns in South Africans. As the reasons why individuals are differently affected (extent, rate) by senescence or tooth loss are unclear, the influence of other biological factors (sex, ancestry) was also considered. Using micro-focus X-ray Computed Tomography (micro-CT) scans of 333 mandibles, external dimensions, and inner parameters, namely the cortical thickness (CtTh) and cortical density (approximated by histomorphometric parameters, BV/TV) were measured. To assess whether the mandible ages in the same way and rate as the rest of the skeleton, a comparison of mandibular and femoral cortical BV/TV, using a micro-CT subsample of 68 individuals, was included. A comprehensive assessment of the mandibular morphology and cortical microstructure of fully dentate individuals highlighted that the smaller the alveolar height is, the thicker and denser the cortical bone. An inner cortical asymmetry between basal, buccal, and lingual areas was described for CtTh, but was absent for BV/TV. Sexual dimorphism and ancestral variations were confirmed for the external distances and CtTh, but not for BV/TV. With tooth loss, a general decrease in external distances (aggravated by edentulism), CtTh and BV/TV was observed, except at the midline where the lingual CtTh increased with edentulism. Sexual dimorphism and ancestral variations of the external dimensions and CtTh were emphasised in edentulous mandibles. The cortical density decreased with aging, corroborating the general decline in bone mass of the skeleton, as noted in the femur. By contrasting the effects of tooth loss and aging, it was concluded that both external distances and CtTh were mainly influenced by tooth loss and not age, whereas the cortical bone density displayed an age-related decrease independent of tooth loss. To ascertain the applicability of the findings in a dental setting, where Cone-Beam Computed Tomography (CBCT) is commonly used, measurements were performed on 24 mandibles scanned by both CBCT and micro-CT (considered as the reference). The accuracy and repeatability of CBCT was confirmed for large-scale measurements, and CtTh in a lesser manner, whereas results were uncertain for BV/TV, revealing a distinct lack of reliability. In conclusion, this thesis inferred the precise role of aging and tooth loss, but also sex and ancestry, on the variations of the mandibular macro- and microstructure. Not only does knowledge and understanding of these changes have implications in dentistry fields, as cortical thickness and density are essential for many dental procedures; but also in biological anthropology, in which the microstructure of extant human mandibles gives valuable insights into intra- and interspecific variations (e.g., sexual dimorphism), or functional considerations (mastication, diet) of archaeological/fossil specimens.AnatomyPhD (Anatomy)Unrestricte

    Advanced analytical diagnostics applied to human osteological remains

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    Le ossa antiche, recuperate dai contesti archeologici e preservati all’interno dei Musei, rappresentano una preziosa fonte di informazioni sull'alimentazione, lo stato di salute, la mobilità delle popolazioni antiche nonché sulla demografia e condizioni ambientali del passato, utili a ricercatori e accademici. A seguito dello sviluppo di moderne tecnologie delle scienze omiche, i reperti osteologici sono sempre più richiesti e questo ha comportato un aumento dell'analisi del DNA antico (aDNA). I metodi di campionamento per l'estrazione del DNA antico sono prevalentemente distruttivi e spesso possono compromettere i reperti osteologici per ulteriori future analisi o per studi in altri campi di ricerca. Oltre al campionamento invasivo e distruttivo, in condizioni di scarsa conservazione dell’osso archeologico causata da alterazioni tafonomiche e diagenetiche, il sequenziamento del DNA antico può essere un'operazione estremamente costosa. Dati gli elevati costi della procedura di sequenziamento dell'aDNA, in questo lavoro di ricerca è stato condotto uno studio analitico mediante spettroscopia a raggi infrarossi (FTIR) per sviluppare un metodo di pre-screening affidabile, veloce ed economico per determinare la presenza/assenza di molecole genetiche in un campione osseo archeologico. La spettroscopia IR è uno strumento utile in quanto è rapida, minimamente distruttiva, economica e sensibile alle variazioni delle proprietà strutturali delle componenti organiche (collagene) e inorganiche (nano cristalli di bioapatite) che costituiscono l’osso. A livello ultrastrutturale, le componenti organiche e inorganiche possono stabilire forti legami con il DNA , stabilizzandolo e determinando la sua sopravvivenza nel tempo. Da campioni archeologici (di epoche e provenienze diverse) estremamente alterati a moderne ossa fresche, abbiamo valutato la sensibilità e l'efficacia di nuovi parametri IR per caratterizzare la diagenesi subita dalle ossa tenendo in considerazioni i cambiamenti delle condizioni climatico–ambientali e di seppellimento. Il lavoro è stato esteso per esaminare le modificazioni indotte dalla diagenesi sulla struttura secondaria del collagene conservato, valutandone gli effetti sui cristalli di bioapatite. I risultati ottenuti dimostrano che il parametro IR che descrive l’ordine/disordine atomico, utilizzato in questa ricerca, è vantaggioso per il monitoraggio di variazioni minime nella struttura e nelle proprietà chimiche della bioapatite nonché indirettamente nel collagene. Questo metodo potrebbe migliorare il processo di selezione dei campioni ossei nonché la loro idoneità per analisi specifiche, ad es. analisi genetiche, paleoproteomiche e degli isotopi stabili sulla base delle analisi spettrali. Viene qui proposto inoltre un modello predittivo funzionale con i parametri infrarossi utilizzati, al fine di determinare il parametro più predittivo per la prensenza/assenza di DNA, utile per ridurre i costi delle analisi genetiche. Dai dati ottenuti, la qualità/quantità di aDNA risulterebbe non essere determinabile a causa dell'influenza di fattori ambientali locali.Ancient bone tissues, recovered from archaeological contexts and preserved within the Museums, represent a valuable source of information on health, diet, mobility of ancient populations as well as on demographics and environmental conditions of the past, useful for researchers and academics. Following the development of modern technologies of omic sciences, osteological finds are increasingly requested and this has led to an increase in the analysis of ancient DNA (aDNA). Sampling methods for ancient DNA extraction are predominantly destructive and may often compromise osteological findings for further future analysis or for studies in other research fields. In addition to invasive and destructive sampling, in poor conservation conditions of the archaeological bone caused by taphonomic and diagenetic alterations, the sequencing of ancient DNA can be an extremely expensive operation. Given the high costs of the aDNA sequencing procedure, an analytical study by means of infrared spectroscopy (FTIR) was conducted in this research work to develop a reliable, fast and inexpensive pre-screening method to determine presence/absence of genetic molecules in an archaeological bone sample. Infrared spectroscopy is a useful tool fast, minimally destructive, inexpensive and sensitive to changes in the structural properties of the organic (collagen) and inorganic (bioapatite nanocrystals) components that make up bone. At the ultrastructural level, the organic and inorganic components of bone may stabilize strong bounds with DNA, stabilizing it and determining its survival over time. The sensitivity and efficiency of new IR parameters was tested on fresh bones and extremely altered archaeological samples, characterized by different chronology and origin. The diagenesis undergone by the bones was characterized taking into account changes in climatic-environmental and burial conditions. The research was expanded by examining changes induced by diagenesis on the secondary structure of collagen preserved, evaluating their effects on bioapatite crystals. The results obtained demonstrate that the IR parameter used in this research, that describes the atomic order/disorder, is advantageous for monitoring minimal changes in the structure and chemical properties of bioapatite as well as indirectly in collagen. This method may improve the selection process of bone samples as well as their suitability for specific analyzes, e.g. genetic, paleo-proteomic and stable isotope analysis on the basis of infrared spectra. A functional predictive model with the infrared parameters used, in order to determine the most predictive parameter for the presence/absence of DNA, allowing to reduce the costs of genetic analyzes, was proposed here. The results obtained, shows that the quality/quantity of aDNA cannot be determined due to the influence of local environmental factors

    Computer‑aided craniofacial superimposition validation study: the identification of the leaders and participants of the Polish‑Lithuanian January Uprising (1863–1864)

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    In 2017, a series of human remains corresponding to the executed leaders of the “January Uprising” of 1863–1864 were uncovered at the Upper Castle of Vilnius (Lithuania). During the archeological excavations, 14 inhumation pits with the human remains of 21 individuals were found at the site. The subsequent identification process was carried out, including the analysis and cross-comparison of post-mortem data obtained in situ and in the lab with ante-mortem data obtained from historical archives. In parallel, three anthropologists with diverse backgrounds in craniofacial identification and two students without previous experience attempted to identify 11 of these 21 individuals using the craniofacial superimposition technique. To do this, the five participants had access to 18 3D scanned skulls and 14 photographs of 11 different candidates. The participants faced a cross-comparison problem involving 252 skull-face overlay scenarios. The methodology follows the main agreements of the European project MEPROCS and uses the software Skeleton-ID™. Based on MEPROCS standard, a final decision was provided within a scale, assigning a value in terms of strong, moderate, or limited support to the claim that the skull and the facial image belonged (or not) to the same person for each case. The problem of binary classification, positive/negative, with an identification rate for each participant was revealed. The results obtained in this study make the authors think that both the quality of the materials used and the previous experience of the analyst play a fundamental role when reaching conclusions using the CFS technique.CRUE-CSICSpanish Government Junta de Andalucia CONFIA 2021/C005/00141299 EXAISFI PID2021-122916NB-I00Centro de Investigacion de Galicia "CITIC" - Xunta de Galicia P18-FR-4262European Union (European Regional Development Fund-Galicia 2014-2020 Program)Ministry of Science, ICT & Future Planning, Republic of Korea ED431G 2019/01Universidade da Cor una/CISUG RYC2020-029454-

    Nuevo enfoque morfométrico para el estudio de la biomecánica y adaptación de los homininos del Plio-Pleistoceno

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    Tesis inédita de la Universidad Complutense de Madrid, Facultad de Geografía e Historia, leída el 06-10-2021En la presente tesis doctoral titulada “Nuevo enfoque morfométrico para el estudio dela biomecánica y adaptación de los homininos del Plio-Pleistoceno” se presenta una nueva metodología para el análisis de los huesos largos de grandes simios a partir del uso de modelos tridimensionales, haciendo especial hincapié en la interpretación biomecánica de los restos fósiles relativos a especies de nuestra familia evolutiva. Los recientes hallazgos de nuevas especies fósiles humanas han puesto de manifiesto la gran complejidad de nuestra historia evolutiva y las dificultades que entraña su interpretación. Añadido a esto, el estudio de los huesos largos (húmero, radio, cúbito, fémur, tibia y fíbula) de especies homininas anteriores a la nuestra resulta especialmente problemático por una serie de razones entre las que destaca la obtención de información a partir de restos de pequeño tamaño que, en ocasiones, aparecen muy fragmentados en los yacimientos. Asimismo, existen otro tipo de limitaciones que afectan al estudio de la morfología y biomecánica de los huesos largos, entre las que se encuentran la baja integridad del registro fósil y la escasez de restos postcraneales, la dificultad para delimitar los factores que influyen en la morfología de los huesos y que, por lo tanto, pueden mermar la estimación del vínculo existente entre morfología y función, y el uso de muestras comparativas que incluyen un número muy limitado de grupos y morfologías. Esta tesis doctoral tiene como objetivo principal el desarrollo de un nuevo enfoque morfométrico para el estudio de la biomecánica y adaptación de los homininos del Plio-Pleistoceno apoyado en una caracterización muy detallada de la morfologíaexterna de los huesos largos y la implementación de modelos de clasificación de alta precisión...In the present doctoral thesis entitled "A new morphometric approach to the study of Plio-Pleistocene hominin biomechanics and adaptation" a new 3D methodology for the analysis of great ape long bones with special emphasis on the biomechanical interpretation of human fossil remains is introduced. Recent findings of human fossil specimens and taxa have revealed the great complexity of our evolutionary history and the difficulties involved in its comprehension and interpretation. Moreover, the study of hominin long bone remains (humerus, radius, ulna, femur, tibia, fibula) in Palaeoanthropologyis particularly problematic due to the difficulties involved in the analysis of fragmentary skeletal elements that in many occasions are merely represented by small diaphyseal portions. On top of that, there are several additional limitations that affect our ability to study fossil long bone morphology and draw biomechanical inferences, such as the scarcity and poor integrity of the fossil record; the delimitation of the factors that influence morphology and that might diminish the link between bone morphologyand function; and the widespread use of limited modern reference samples that encompass low degrees of interspecific variability. The main objective of the present research is the development of a new morphometric approach to the study of Plio-Pleistocene hominin biomechanics and adaptation that relies on the detailed quantitative characterisation of the external long bone morphology and the implementation of powerful classification methods...Fac. de Geografía e HistoriaTRUEunpu

    Artificial Intelligence in Oral Health

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    This Special Issue is intended to lay the foundation of AI applications focusing on oral health, including general dentistry, periodontology, implantology, oral surgery, oral radiology, orthodontics, and prosthodontics, among others
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