Enhanced Computerized Surgical Planning System in Craniomaxillofacial Surgery

In the field of craniomaxillofacial (CMF) surgery, surgical planning is an important and necessary procedure due to the complex nature of the craniofacial skeleton. Computed tomography (CT) has brought about a revolution in virtual diagnosis, surgical planning and simulation, and evaluation of treatment outcomes. It provides high-quality 3D image and model of skull for Computer-aided surgical planning system (CSPS). During the planning process, one of the essential steps is to reestablish the dental occlusion. In the first project, a new approach is presented to automatically and efficiently reestablish dental occlusion. It includes two steps. The first step is to initially position the models based on dental curves and a point matching technique. The second step is to reposition the models to the final desired occlusion based on iterative surface-based minimum distance mapping with collision constraints. With linearization of rotation matrix, the alignment is modeled by solving quadratic programming. The simulation was completed on 12 sets of digital dental models. Two sets of dental models were partially edentulous, and another two sets have first premolar extractions for orthodontic treatment. Two validation methods were applied to the articulated models. The results show that using the proposed method, the dental models can be successfully articulated with a small degree of deviations from the occlusion achieved with the gold-standard method. Low contrast resolution in CBCT image has become its major limitation in building skull model. Intensive hand-segmentation is required to reconstruct the skull model. Thin bone images are particularly affected by this limitation. In the second project, a novel segmentation approach is presented based on wavelet active shape model (WASM) for a particular interest in the outer surface of the anterior wall of maxilla. 19 CBCT datasets are used to conduct two experiments. This model-based segmentation approach is validated and compared with three different segmentation approaches. The results show that the performance of this model-based segmentation approach is better than those of the other approaches. It can achieve 0.25 +/- 0.2mm of surface error distance from the ground truth of the bone surface. Field of view (FOV) can be reduced in order to reduce unnecessary radiation dose in CBCT. This ROI imaging is common in most of the dentomaxillofacial imaging and orthodontic practices. However, a truncation effect is created due to the truncation of projection images and becomes one of the limitation in CBCT. In the third project, a method for small region of interest (ROI) imaging and reconstruction of the image of ROI in CBCT and two experiments for measurement of dosage are presented. The first experiment shows at least 60% and 70% of radiation dose can be reduced. It also demonstrates that the image quality was still acceptable with little variation of gray by using the traditional truncation correction approach for ROI imaging. The second experiment demonstrates that the images reconstructed by CBCT reconstruction algorithms without truncation correction can be degraded to unacceptable image quality

АНАЛІЗ ПРОБЛЕМ ТА МОЖЛИВОСТЕЙ ВІДТВОРЕННЯ АРТИКУЛЯЦІНИХ РУХІВ ЩЕЛЕПИ У ЦИФРОВОМУ СЕРЕДОВИЩІ

Introduction. The use of virtual articulators, which are essentially software, greatly enhances the effectiveness of planning and implementing stages of complex dental rehabilitation with the ability to completely translate patient data (not only anatomical but also functional) into a digital format.The aim of study. Carry out an analysis of design and simulation systems for jaw kinematic parameters reproduction, basic principles of the architecture of existing software aimed at reproducing articulation components and constructing individualized occlusion patterns during patient-oriented prosthetic treatment.Materials and methods. The search for publications in electronic databases (PubMedCentral (PMC), BioMed Central, InTech, MEDLINE / PubMed, the Public Library of Science One (PloS)) was carried out in accordance with the Medical Subject Headings (MeSH) descriptors, which are peculiar headings categorized by the hierarchy system. Additionally, the analysis of references in already pre-made system reviews related to the objectives of this study and other review publications adjacent to them was provided.Results. The systematic review of the principles of digital modeling of articulation schemes with different initial conditions confirmed the possibility of their practical application during the manufacture of prosthetic elements with individualized occlusive surfaces, thus ensuring the achievement of the best results of dental rehabilitation.Conclusions. A systematic review of the main possibilities for reproduction jaw articulation movements in the digital environment is the primary stage in the development of an own model of a digital atticulator to address specific clinical problems associated with prosthetic retreatment of patients with present occlusive dysfunctions.Введение. Использование виртуальных артикуляторов, которые по сути представляют собой программное обеспечение, значительно повышает эффективность планирования и реализация этапов комплексной стоматологической реабилитации с возможностью полного перевода данных пациента (не только анатомических, но и функциональных) в цифровой формат.Цель исследования. Провести анализ систем дизайна и имитации кинематических параметров челюсти, основных принципов архитектуры имеющегося программного обеспечения направленного на воспроизводство артикуляционных составляющих и построение индивидуализированных окклюзионных схем в ходе пациент-ориентированного ортопедического лечения.Материалы и методы. Поиск публикаций в электронных базах данных (PubMedCentral (PMC), BioMed Central, InTech, MEDLINE / PubMed, Public Library of Science One (PloS)) осуществлялся согласно дескрипторов Medical Subject Headings (MeSH), представляющих собой своеобразные заголовки, категоризированных по системе иерархии. Дополнительно проводился анализ ссылок в уже предварительно проведенных системных обзорах, касающихся цели данного исследования, и других обзорных публикациях, смежных с ними.Результаты исследования. Проведенный системный обзор принципов цифрового моделирования артикуляционных схем с различными исходными условиями подтвердил возможность их практического применения при изготовлении протетических элементов с индивидуализированными окклюзионными поверхностями, обеспечивая таким образом достижение наиболее оптимальных результатов стоматологической реабилитации.Выводы. Системный обзор основных возможностей воспроизведения артикуляционных движений челюсти в цифровой среде является первичным этапом разработки собственной модели цифрового атикулятора для решения конкретных клинических проблем, связанных с повторным протезированием пациентов с имеющимися окклюзионными дисфункциями.Вступ. Використання віртуальних артикуляторів, що по суті представляють собою програмне забезпечення, значно підвищує ефективність планування та реалізація етапів комплексної стоматологічної реабілітації з можливістю повного переведення даних пацієнта (не тільки анатомічних, а й функціональних) у цифровий формат.Мета дослідження. Провести аналіз систем дизайну та імітації кінематичних параметрів щелепи, основних принципів архітектури наявного програмного забезпечення спрямованого на відтворення артикуляційних складових та побудову індивідуалізованих оклюзійних схем в ході пацієнт-орієнтованого ортопедичного лікування.Матеріали та методи. Пошук публікацій у електронних базах даних (PubMedCentral (PMC), BioMed Central, InTech, MEDLINE/ PubMed, Public Library of Science One (PloS)) здійснювався згідно дескрипторів Medical Subject Headings (MeSH), що становлять собою своєрідні заголовки, категоризовані за системою ієрархії. Додатково проводився аналіз посилань в уже попередньо проведених системних оглядах, що стосувалися мети даного дослідження, та інших оглядових публікаціях, суміжних із ними.Результати дослідження. Проведений системний огляд принципів цифрового моделювання артикуляційних схем з різними вихідними умовами підтвердив можливість їх практичного застосування під час виготовлення протетичних елементів з індивідуалізованими оклюзійними поверхнями, забезпечуючи таким чином досягнення найбільш оптимальних результатів стоматологічної реабілітації.Висновки. Системний огляд основних можливостей відтворення артикуляційних рухів щелепи в цифровому середовищі є первинним етапом розробки власної моделі цифрового атикулятора для вирішення конкретних клінічних проблем пов’язаних із повторним протезуванням пацієнтів із наявними оклюзійними дисфункціями

Contributions to the three-dimensional virtual treatment planning of orthognathic surgery

Orientadores: José Mario De Martino, Luis Augusto PasseriTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: A tecnologia mais recente à disposição da Cirurgia Ortognática possibilita que o diagnóstico e o planejamento do tratamento das deformidades dentofaciais sejam realizados sob uma representação virtual tridimensional (3D) da cabeça do paciente. Com o propósito de contribuir para o aperfeiçoamento desta tecnologia, o trabalho apresentado nesta tese identificou e tratou quatro problemas. A primeira contribuição consistiu na verificação da validade da hipótese de que a mudança de definição do plano horizontal de Frankfort não produz diferenças de medição clinicamente relevantes quando sob indivíduos cujos crânios são consideravelmente simétricos. Os resultados da análise realizada no contexto deste tese indicam que, ao contrário do que se presumia, a hipótese é falsa. A segunda contribuição consistiu na extensão do método de análise cefalométrica de McNamara para que ele pudesse produzir valores 3D. Ao contrário de outros métodos de análise cefalométrica 3D, a extensão criada produz valores verdadeiramente 3D, não perde as informações do método original e preserva as definições geométricas originais das linhas e planos cefalométricos. A terceira contribuição consistiu a) no estabelecimento de normas cefalométricas para brasileiros adultos de ascendência europeia, a partir de imagens de tomografia computadorizada de feixe cônico, que produz uma imagem craniofacial mais precisa e confiável do que a telerradiografia; e b) na avaliação de dimorfismo sexual, para a identificação de características anatômicas diferenciadas entre homens e mulheres desta população. A quarta e última contribuição consistiu na automatização da principal etapa da tecnologia em questão, na qual o cirurgião executa o reposicionamento dos segmentos ósseos maxilares no crânio. O método criado é capaz de corrigir automaticamente os problemas dentofaciais mais comuns tratados pela Cirurgia Ortognática, que envolvem maloclusão esquelética, assimetria facial e discrepância de maxilares. Todas as contribuições deste trabalho foram publicadas em periódicos internacionais do campo da Odontologia e afinsAbstract: The latest technology available for orthognathic surgery allows the diagnosis and treatment planning of dentofacial deformities based on a three-dimensional (3D) virtual representation of the patient's head. In order to contribute to the improvement of this technology, the work presented in this thesis identified and treated four problems. The first contribution consisted in testing the validity of the hypothesis that changing the definition of the Frankfort horizontal plane does not produce clinically relevant measurement differences for subjects whose skulls are considerably symmetrical. The results of the analysis performed in this thesis indicate that, contrary to what was presumed, the hypothesis is false. The second contribution is an extension of the McNamara's method of cephalometric analysis to produce 3D values. Unlike other methods of 3D cephalometric analysis, the extension produces true 3D values, does not lose information captured by the original method, and preserves the original geometric definitions of the cephalometric lines and planes. The third contribution consisted in a) establishing cephalometric norms for Brazilian adults of European descent, based on images from cone-beam computed tomography, which produce a more accurate and reliable craniofacial image than cephalometric radiography; and b) evaluating sexual dimorphism, for the identification of distinct anatomic features between males and females of this population. The fourth contribution consisted in automating the main stage of the technology in question, in which the surgeon performs the positioning of jaw bone segments in the skull. The created method is able to automatically correct the most common dentofacial problems treated by orthognathic surgery, which involves skeletal malocclusion, facial asymmetry, and jaw discrepancy. The contributions of this work were published in international journals of the field of Dentistry and relatedDoutoradoEngenharia de ComputaçãoDoutor em Engenharia ElétricaCAPE

Imaging dental ultrasonic cavitation and its effects

Current methods of dental biofilm removal are predominantly mechanical and are not effective in removing it from irregular surfaces in the mouth. Cavitation occurs around dental ultrasonic scalers and may be a more efficient and less damaging technique. Previous work has failed to quantify the cavitation bubble dynamics around ultrasonic scalers and its effects. The aim was to develop imaging and analysis protocols to analyse the cavitation and to investigate its ability to disrupt biofilms and deliver sub-micron particles into dentine. High speed imaging was used to characterise cavitation. Its effect on biofilm removal and dentinal tubule occlusion was studied using electron microscopy and x-ray micro computed tomography. We are able to demonstrate that cavitation occurs at the free end of scaler tips and increases with power and vibration amplitude. Biofilm can effectively be removed from dental implant surfaces using this cavitation. It can also be used to transport sub-micron particles further into dentinal tubules. The results show that ultrasonic scalers could be optimised for non-contact use and improved removal of plaque from the teeth. The protocols established in this study can be applied to future studies for quantitative investigation of biofilm growth and removal and analysis of cavitation dynamics

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf

Medical Robotics

The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

A Textbook of Advanced Oral and Maxillofacial Surgery

The scope of OMF surgery has expanded; encompassing treatment of diseases, disorders, defects and injuries of the head, face, jaws and oral cavity. This internationally-recognized specialty is evolving with advancements in technology and instrumentation. Specialists of this discipline treat patients with impacted teeth, facial pain, misaligned jaws, facial trauma, oral cancer, cysts and tumors; they also perform facial cosmetic surgery and place dental implants. The contents of this volume essentially complements the volume 1; with chapters that cover both basic and advanced concepts on complex topics in oral and maxillofacial surgery