Interactive H5P content for increased student engagement in a dental hygiene program.

Background: Presently, dental hygiene education is primarily divided into classroom lectures, simulation labs, and clinical experiences. Although the recent surge of curriculum renovation in dental and medical schools centres around enhancing student engagement and active learning, classroom teaching remains teacher-focussed, involving students mainly as passive learners. H5P is an open platform for creating and sharing interactive HTML5 learning content. A large set of H5P content was created and provided to students through the learning management system as supplementary material for an oral biology course in the dental hygiene program at a Canadian university. This study was conducted to evaluate the impact of this interactive H5P content on the students' learning experiences. Methods: The third-year dental hygiene students enrolled in the oral biology course were invited to participate in the study. Anonymised student performance data from the summative exam were analysed, and a survey regarding the student experience with the supplementary H5P content was administered. Results: Students performed better on questions for which H5P supplements were provided. The results from the survey showed satisfaction and perceived benefit of using H5P as supplementary content in didactic lectures. Discussion: The H5P content allowed students to apply knowledge and reproduce understanding, promoting active learning in the didactic oral biology course. Students appreciated the content's interactive nature and expressed willingness to have similar experiences in other courses. Conclusion: Using H5P, interactive learning content can promote self-directed and personalized learning. This open learning platform has the potential to redefine didactic teaching by fostering an active learning environment.

Contexte: À l'heure actuelle, la formation en hygiène dentaire s'appuie principalement sur des exposés en classe, des simulations en laboratoire et des expériences cliniques. Bien que la récente vague de révision des programmes d'études des écoles dentaires et de médecine soit axée sur le renforcement de l'engagement des étudiants et de l'apprentissage actif, le travail en classe reste axé sur l'enseignement par un enseignant : dans ce contexte, les étudiants sont principalement des apprenants passifs. H5P est une plateforme ouverte pour la création et le partage de contenu d'apprentissage interactif au format HTML5. Un vaste ensemble de contenu H5P a été créé et fourni aux étudiants, par l'entremise du système de gestion de l'apprentissage, à titre de matériel supplémentaire pour un cours de biologie buccale dans le cadre du programme d'hygiène dentaire d'une université canadienne. Cette étude a été effectuée pour évaluer les effets de ce contenu H5P interactif sur les expériences d'apprentissage des étudiants. Méthodes: Les étudiants en hygiène dentaire de troisième année inscrits au cours de biologie buccale ont été invités à participer à l'étude. Des données anonymisées sur le rendement des étudiants provenant de l'examen sommatif ont été analysées, et un sondage sur l'expérience des étudiants avec le contenu H5P supplémentaire a été mené. Résultats: Les résultats des étudiants étaient meilleurs pour les questions pour lesquelles du contenu H5P supplémentaire a été fourni. Les résultats de l'enquête ont révélé les avantages perçus de l'utilisation du contenu H5P supplémentaire dans les cours didactiques, ainsi que la satisfaction en la matière. Discussion: Le contenu H5P a permis aux étudiants d'appliquer les connaissances et de reproduire la compréhension, favorisant ainsi l'apprentissage actif dans le cadre des cours didactiques de biologie buccale. Les étudiants ont apprécié la nature interactive du contenu et se sont dits prêts à répéter l'expérience dans le cadre d'autres cours. Conclusion: Grâce à H5P, le contenu d'apprentissage interactif peut favoriser l'apprentissage autodirigé et personnalisé. Cette plateforme d'apprentissage ouverte a le potentiel de redéfinir l'enseignement didactique en favorisant un environnement d'apprentissage actif.

Bioinformatics for Dentistry: A secondary database for the genetics of tooth development.

Genes strictly regulate the development of teeth and their surrounding oral structures. Alteration of gene regulation leads to tooth disorders and developmental anomalies in tooth, oral, and facial regions. With the advancement of gene sequencing technology, genomic data is rapidly increasing. However, the large sets of genomic and proteomic data related to tooth development and dental disorders are currently dispersed in many primary databases and literature, making it difficult for users to navigate, extract, study, or analyze. We have curated the scattered genetic data on tooth development and created a knowledgebase called 'Bioinformatics for Dentistry' (https://dentalbioinformatics.com/). This database compiles genomic and proteomic data on human tooth development and developmental anomalies and organizes them according to their roles in different stages of tooth development. The database is built by systemically curating relevant data from the National Library of Medicine (NCBI) GenBank, OMIM: Online Mendelian Inheritance in Man, AlphaFold Protein Structure Database, Reactome pathway knowledgebase, Wiki Pathways, and PubMed. The accuracy of the included data was verified from supporting primary literature. Upon data curation and validation, a simple, easy-to-navigate browser interface was created on WordPress version 6.3.2, with PHP version 8.0. The website is hosted in a cloud hosting service to provide fast and reliable data transfer rate. Plugins are used to ensure the browser's compatibility across different devices. Bioinformatics for Dentistry contains four embedded filters for complex and specific searches and free-text search options for quick and simple searching through the datasets. Bioinformatics for Dentistry is made freely available worldwide, with the hope that this knowledgebase will improve our understanding of the complex genetic regulation of tooth development and will open doors to research initiatives and discoveries. This database will be expanded in the future by incorporating resources and built-in sequence analysis tools, and it will be maintained and updated annually.

Live quiz games to teach nutrition in a dental hygiene program: a pilot study.

Introduction: Higher educational institutions increasingly focus on incorporating games to enhance student engagement. Gimkit is a recent addition to gamified learning that allows instructors to create quiz games with randomly repeated questions. Case description: The study of nutrition requires memorization of facts. Gimkit was incorporated into a dental hygiene class to teach nutrition and support rote learning. Anonymous data on student performance and satisfaction were collected. Descriptive statistics were applied to summarize the survey results; the difficulty and discrimination indices were analyzed to evaluate students' academic performance. Results: Ten percent of the class participated in the voluntary survey; academic performance was analyzed for the whole class. The study identified Gimkit as a potential learning tool, especially for content areas that require memorization and learning of facts. Conclusion: Data show a positive impact of in-class gaming on knowledge acquisition and retention.

Introduction: Les établissements d'enseignement supérieur se concentrent de plus en plus sur l'intégration de jeux pour renforcer l'engagement des étudiants. Gimkit est un ajout récent à l'éventail d'outils d'apprentissage ludique qui permet aux instructeurs de créer des jeux-questionnaires avec des questions répétées au hasard. Description de cas: L'étude de la nutrition nécessite de mémoriser des faits. Gimkit a été intégré à un cours d'hygiène dentaire pour enseigner la nutrition et favoriser l'apprentissage par mémorisation. On a recueilli des données anonymes sur les résultats et la satisfaction des élèves. On a eu recours à des méthodes de statistique descriptive pour résumer les résultats du sondage; les indices de difficulté et de discrimination ont été analysés pour évaluer le rendement universitaire des étudiants. Résultats: Dix pour cent des étudiants qui suivaient le cours ont répondu à ce sondage facultatif; on a analysé le rendement universitaire de l'ensemble de la classe. L'étude a établi que Gimkit était un outil d'apprentissage potentiel, en particulier dans les domaines qui nécessitent l'apprentissage et la mémorisation de faits. Conclusion: Les données montrent une incidence positive de l'utilisation des jeux dans le cadre du cours sur l'acquisition et la rétention des connaissances.

Effect of teaching tools in spatial understanding in health science education: a systematic review.

Background: The concept of spatial orientation is integral to health education. Students studying to be healthcare professionals use their visual intelligence to develop 3D mental models from 2D images, like X-rays, MRI, and CT scans, which exerts a heavy cognitive load on them. Innovative teaching tools and technologies are being developed to improve students' learning experiences. However, the impact of these teaching modalities on spatial understanding is not often evaluated. This systematic review aims to investigate current literature to identify which teaching tools and techniques are intended to improve the 3D sense of students and how these tools impact learners' spatial understanding. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines were followed for the systematic review. Four databases were searched with multiple search terms. The articles were screened based on inclusion and exclusion criteria and assessed for quality. Results: Nineteen articles were eligible for our systematic review. Teaching tools focused on improving spatial concepts can be grouped into five categories. The review findings reveal that the experimental groups have performed equally well or significantly better in tests and tasks with access to the teaching tool than the control groups. Conclusion: Our review investigated the current literature to identify and categorize teaching tools shown to improve spatial understanding in healthcare professionals. The teaching tools identified in our review showed improvement in measured, and perceived spatial intelligence. However, a wide variation exists among the teaching tools and assessment techniques. We also identified knowledge gaps and future research opportunities.

Contexte: Le concept d'orientation spatiale fait partie intégrante de l'enseignement des professions de la santé. Les étudiants utilisent leur intelligence visuelle pour se représenter mentalement en 3D des images en 2D comme des radiographies, de l'IRM et des coupes tomodensitométriques, ce qui constitue une lourde charge cognitive. On développe actuellement des technologies et des outils pédagogiques innovants pour améliorer l'expérience d'apprentissage des étudiants. Cependant, l'impact de ces ressources pédagogiques sur la perception spatiale est rarement évalué. L'objectif de cette revue systématique de la littérature était de recenser les outils et techniques pédagogiques destinés à améliorer la perception 3D des apprenants et d'évaluer les effets de ces outils sur leur perception spatiale. Méthodes: Suivant les lignes directrices PRISMA, nous avons consulté quatre bases de données avec des termes de recherche multiples, analysé les articles recensés en fonction de critères d'inclusion et d'exclusion, et évalué leur qualité. Résultats: Dix-neuf articles correspondaient aux critères d'inclusion. Les outils pédagogiques axés sur l'amélioration de la perception spatiale peuvent être regroupés en cinq catégories. L'examen a révélé que les résultats obtenus par les groupes expérimentaux ayant utilisé l'outil pédagogique pour effectuer les tests et les tâches demandés sont aussi bons ou significativement meilleurs que les résultats obtenus par les groupes témoins. Conclusion: Notre revue de la littérature visant à recenser et catégoriser les outils pédagogiques disponibles a montré que ces derniers améliorent la perception spatiale, notamment l'intelligence spatiale mesurée et perçue, des professionnels de la santé. Toutefois, il existe une grande variation entre les divers outils pédagogiques et techniques d'évaluation. Nous avons également relevé des lacunes dans nos connaissances et des pistes de recherche future.

Development of a Secondary Dental-Specific Database for Active Learning of Genetics in Dentistry Programs.

OBJECTIVES: Dental students study the genetics of tooth and facial development through didactic lectures only. Meanwhile, scientists' knowledge of genetics is rapidly expanding, over and above what is commonly found in textbooks. Therefore, students studying dentistry are often unfamiliar with the burgeoning field of genetic data and biological databases. There is also a growing interest in applying active learning strategies to teach genetics in higher education. We developed a secondary database called "Genetics for Dentistry" to use as an active learning tool for teaching genetics in dentistry programs. The database archives genomic and proteomic data related to enamel and dentin formation. METHODS: We took a systematic approach to identify, collect, and organize genomic and proteomic tooth development data from primary databases and literature searches. The data were checked for accuracy and exported to Ragic to create an interactive secondary database. RESULTS: "Genetics for Dentistry," which is in its initial phase, contains information on all the human genes involved in enamel and dentin formation. Users can search the database by gene name, protein sequence, chromosomal location, and other keywords related to protein and gene function. CONCLUSIONS: "Genetics for Dentistry" will be introduced as an active learning tool for teaching genetics at the School of Dentistry of the University of Alberta. Activities using the database will supplement lectures on genetics in the dentistry program. We hope that incorporating this database as an active learning tool will reduce students' cognitive load in learning genetics and stimulate interest in new branches of science, including bioinformatics and precision dentistry.

The perceptions of dental hygiene students about an asynchronous oral biology course.

Background: Medical and dental schools have long-established pedagogical approaches to teacher-centred face-to-face learning. The 3-year baccalaureate dental hygiene (DH) program at the University of Alberta, which enrolls 42 students of diverse ages and experiences each year, is no exception. Oral Biology II (OBIOL 302) is an intermediate-level course in the DH program; it was moved to an asynchronous online format to manage the disruptions of the COVID-19 pandemic. This mixed-method study explores the factors affecting the dental hygiene student experience in this online, asynchronous learning environment. Methods: This study used a quantitative anonymous survey with a 5-point Likert scale to evaluate the workload and flexibility of the course as well as student acceptance of the assessments. The mean score and standard deviation were calculated for each question in the online survey. A research facilitator conducted interviews using a semi-structured interview guide to further explore student experiences. The qualitative data were then analyzed using a 6-step method of thematic analysis. Results: The study participants found the format and workload of the online course appropriate and well-suited to the spring term. Thematic analysis of the qualitative data revealed 3 intersecting elements-course structure, communication, and non-curricular aspects-as the key factors shaping student experiences in an online environment. Conclusion: ,This study identified the major factors affecting the online learning experience of students from the students' point of view, which will be a useful guide to design more effective online courses for health science education.

Contexte: Les écoles de médecine et de dentisterie ont depuis longtemps établi des approches pédagogiques en personne centrées sur l'enseignant. Le programme de baccalauréat de 3 ans en hygiène dentaire (HD) de l'Université de l'Alberta, qui accueille chaque année 42 étudiants de divers âges et expériences, ne fait pas exception. En vue de gérer les perturbations de la pandémie de la COVID-19 , Oral BiologyII (OBIOL 302), un cours de niveau intermédiaire au programme d'hygiène dentaire, a été déplacé vers un format asynchrone et en ligne. La présente étude à méthode mixte explore les facteurs qui influencent l'expérience des étudiants en hygiène dentaire dans un environnement d'apprentissage asynchrone et en ligne. Méthodologie: Cette étude a utilisé une enquête quantitative anonyme et une échelle de Likert en 5 points pour évaluer la charge de travail et la flexibilité du cours, ainsi que la manière dont les étudiants ont accueilli les évaluations. La cote moyenne et l'écart type ont été calculés pour chaque question de l'enquête menée en ligne. Un facilitateur de recherche a mené des entretiens à l'aide d'un guide d'entretien semi-structuré en vue d'explorer davantage les expériences des étudiants. Une analyse des données qualitatives a ensuite été réalisée à l'aide d'une méthode d'analyse thématique en 6 étapes. Résultats: Les participants à l'étude ont trouvé le format et la charge de travail du cours en ligne appropriés et bien adaptés au semestre du printemps. L'analyse thématique des données qualitatives a révélé 3 éléments interdépendants comme étant les facteurs clés qui façonnent les expériences des étudiants dans un environnement en ligne : la structure du cours, la communication et les aspects non scolaires. Conclusion: Cette étude a défini les principaux facteurs ayant une incidence sur l'expérience d'apprentissage en ligne des étudiants, selon le point de vue de ces derniers, ce qui constituera un guide utile pour élaborer des cours en ligne plus efficaces pour l'enseignement des sciences de la santé.

Implementing Augmented Reality to Facilitate the Learning of Oral Histology.

OBJECTIVES: The study of biological materials under a microscope is known as histology, which is one of the most challenging subjects for students. Our objective was to develop a learning tool that can reduce the extrinsic load of studying histology and make learning enjoyable and flexible. We used augmented reality (AR) to create a cellphone application called Dental AR. With Dental AR, students can use their cellphones as dynamic flashcards to hide or reveal the annotations of a histology slide. Our application enables students to study, practice, and self-test oral histology knowledge at their own pace. METHODS: We used Unity3D with Vuforia to develop Dental AR. To generate a set of target images, oral histology glass slides were scanned and converted to digital images. Annotated versions of the slides were used as output for the corresponding target images. To understand user experiences and satisfaction with Dental AR, first-year dentistry students were invited to complete an online survey. RESULTS: Dental AR was successfully developed and released on both the Apple and Google Play online app stores. The survey of dentistry students indicated overall satisfaction with Dental AR and willingness to use similar applications in other subjects. CONCLUSIONS: Dental AR can be used for in-class activities, gamification, and providing students with practice questions to study and self-test outside the classroom. This application can be expanded in the future to incorporate more target images, videos, and interactive components to make learning histology less challenging and more enjoyable.

Developing an Interactive Computer Program for Integrated Dental Education.

OBJECTIVES: The knowledge of anatomy is an integral part of dental and medical education that builds the foundations of pathology, physiology, and other related disciplines. Traditional three-dimensional (3D) models used to teach anatomy cannot represent dynamic physiological processes and lack structural detail in the oral regions relevant for dental education. We developed an interactive computer program to teach oral anatomy, pathology, and microbiology in an integrated manner to improve students' learning experiences. METHODS: The computer program, Jawnatomy, was developed as a 3D human head. Cognitive load theory guided the design of the tool, with the goal of reducing the heavy cognitive load of learning anatomy and integrating this knowledge with pathology and microbiology. Keller's attention, relevance, confidence, and satisfaction (ARCS) model of motivational design was used while creating the tool to improve learners' motivation and engagement. Blender was used to create the graphics, and Unity 3D was used to incorporate interactivity in the program. The 3D renderings of oral anatomy and progression of tooth decay were created with the input of content experts. RESULTS: Jawnatomy will be launched in our institution's dentistry and dental hygiene program to support project- and team-based learning. This program will also be introduced to students as a self-directed learning tool to help them practice and strengthen their anatomical knowledge at their own pace. CONCLUSIONS: Surveys and focus groups will be conducted to evaluate and further improve the computer program. We believe that Jawnatomy will become an invaluable teaching tool for dental education.

Admission criteria for Canadian dental hygiene programs.

Objective: The purpose of this project was to understand the variation in admission criteria to Canadian dental hygiene programs and determine whether the criteria are appropriate in predicting a program's success rate on the National Dental Hygiene Certification Exam (NDHCE). Methods: Admission criteria were gathered from the websites of English-language dental hygiene programs in Canada. Individual dental hygiene programs were also contacted directly by phone or email if their admission criteria were not outlined on the program website. NDHCE success rates for each program were collected from the National Dental Hygiene Certification Board website. The association between the admission criteria and NDHCE success rates was examined. Pearson's product moment correlations were performed for post-secondary credits required for admission and program length. Results: Admission criteria for 29 of 30 dental hygiene programs were examined. Twenty-two programs accepted applicants directly from high school. The average program length was 83.7 weeks. Four programs offered post-diploma baccalaureate degrees in dental hygiene; one program offered a direct entry-to-practice degree program. Twenty-two (22) of the 29 programs utilized academic grades (including overall and/or prerequisite GPA) as admission criteria. Twelve programs included interviews in the admission process. A moderate correlation was observed between the number of postsecondary credits required for admission and NDHCE success rates (r = 0.6723). A weak correlation was found between program length and NDHCE success rates (r = 0.1797). Conclusion: Academic performance as an admission criterion, including overall/prerequisite GPA, was the most common criterion used by dental hygiene programs. Graduates from programs that required more postsecondary credits tended to perform better on the NDHCE. The higher success rate may be attributed to the rigour of the prerequisite courses, which may prepare students for dental hygiene studies and ultimately success on the national examination. In addition, students with more postsecondary coursework may be better adjusted to studies at a postsecondary level and/or be more experienced at taking examinations.

Objectif: Le présent projet avait pour but de comprendre la variation des critères d'admission aux programmes d'hygiène dentaire canadiens et d'établir la pertinence des critères dans la prédiction des taux de succès d'un programme à l'examen de certification nationale en hygiène dentaire (ECNHD). Méthodologie: Les critères d'admission ont été obtenus à partir de sites Web de programmes d'hygiène dentaire anglophones au Canada. On a communiqué directement par téléphone et par courriel avec les programmes d'hygiène dentaire individuels si leurs critères d'admission n'étaient pas présentés sur le site Web du programme. Les taux de succès à l'ECNHD de chaque programme ont été recueillis du site Web du Bureau national de la certification en hygiène dentaire. Le lien entre les critères d'admission et les taux de succès à l'ECNHD ont été examinés. La méthode de corrélation de moment-produit de Pearson a été utilisée pour examiner les crédits postsecondaires requis pour l'admission et la longueur du programme. Résultats: Les critères d'admission de 29 des 30 programmes d'hygiène dentaire ont été examinés. Vingt-deux programmes ont admis des étudiants directement de l'école secondaire. La longueur moyenne des programmes était de 83,7 semaines. Quatre programmes offraient des programmes post-diplôme menant au baccalauréat en hygiène dentaire; un programme offrait un programme d'admission directe à la profession. Vingt-deux (22) des 29 programmes utilisaient les notes scolaires (y compris la moyenne pondérée cumulative globale ou de prérequis) comme processus d'admission. Douze programmes avaient un processus d'admission qui comprenait des entrevues. Une corrélation modérée a été observée entre le nombre de crédits postsecondaires requis pour l'admission et les taux de succès à l'ECNHD (r = 0,6723). Une faible corrélation a été trouvée entre la longueur du programme et les taux de succès à l'ECNHD (r = 0,1797). Conclusion: Les programmes d'hygiène dentaire utilisaient le plus fréquemment la performance scolaire comme critère d'admission, y compris la moyenne pondérée cumulative globale ou de prérequis. Les diplômés de programmes qui exigeaient un plus grand nombre de crédits postsecondaires avaient tendance à mieux réussir à l'ECNHD. Le taux de succès plus élevé peut être attribué à la rigueur des cours prérequis, ce qui pourrait préparer les étudiants aux études d'hygiène dentaire et en fin de compte, à la réussite de l'examen national. De plus, les étudiants ayant un plus grand nombre de cours postsecondaires pourraient être davantage prêts aux études de niveau postsecondaire ou être plus à l'aise à faire des examens.

Histoscope: A Web-Based Microscopy Tool for Oral Histology Education.

OBJECTIVES: Histology, the study of tissue structure under a microscope, is one of the most essential yet least engaging topics for health professional students. Understanding tissue microanatomy is crucial for students to be able to recognize cellular structures and follow disease pathogenesis. Traditional histology teaching labs rely on light microscopes and a limited array of slides, which inhibits simultaneous observation by multiple learners, and prevents in-class discussions. We have developed an interactive web-based microscopy tool called "Histoscope" for oral histology in this context. METHODS: Good quality microscope slides were selected for digital scanning. The slides were scanned with multiple layers of z-stacking, a method of taking multiple images at different focal distances. The digital images were checked for quality and were archived on Histoscope. The slides were annotated, and self-assessment questions were prepared for the website. Interactive components were programmed on the website to mimic the experience of using a real light microscope. RESULTS: This web-based tool allows users to interact with histology slides, replicating the experience of observing and manipulating a slide under a real microscope. Through this website, learners can access a broad array of digital oral histology slides and self-assessment questions. CONCLUSIONS: Incorporation of Histoscope in a course can shift traditional teacher-centered histology learning to a collaborative and student-centered learning environment. This platform can also provide students the flexibility to study histology at their own pace.

Augmented Reality Application to Develop a Learning Tool for Students: Transforming Cellphones into Flashcards.

OBJECTIVE: Flashcards are one of the most popular and optimized ways to learn factual knowledge and improve memory performance. Students of modern age, who use smart technology and mobile devices in their daily lives, often lack the time and motivation to create and use flashcards effectively. We aim to use the inseparable relationship between university students and their smartphones to create new options for higher education, converting their cellphones into flashcards. We have used this new technology to develop a simple application (app) to convert the smart mobile devices of students into flashcards. METHODS: We have developed an augmented reality (AR) flashcard application using Unity3D, which requires the user to identify a target image. Once the target image is identified, it can be replaced by any other digital output, i.e., 2D image, 3D models, or videos. We used images of histological sections of oral mucosa, which dentistry students study as a part of an oral biology course. RESULTS: The AR flashcard application worked on both iOS and Android systems. It was able to detect the target image and replace it with the output image on the device screen. CONCLUSION: Using this application, students will be able to independently learn and self-test their learning at their own convenience. Instructors can use the application to provide additional study aids for the students. Our application, which is being developed as a pilot project, will be expanded and applied as a learning tool for students studying dentistry at the University of Alberta.

Admission Criteria as Predictors of Student Success in a Dental Hygiene Program.

The aims of this study were to assess which prerequisites the dental hygiene faculty at the University of Alberta perceived as essential to success in the dental hygiene program and to determine if students' prerequisite grades and interview scores predicted their success in the program. Academic records of students admitted between 2004 and 2013 were examined in 2016 for prerequisite course grades, interview scores, and junior, senior, and cumulative grade point average (GPA). In addition, course instructors were surveyed about which prerequisites they deemed necessary for their particular subjects. The results showed that every prerequisite course was perceived as necessary at some point in the program. However, most prerequisite course grades were weak predictors of academic performance, with a moderate correlation between cumulative prerequisite GPA and the junior GPA and final cumulative GPA. The interview was also considered necessary for some preclinical and clinical courses. There was no correlation between interview scores and students' academic performance. These findings suggest that, although the interview and prerequisite GPA requirements filtered out unsuitable candidates, they did not predict which students would be successful in the program. More refined methods need to be devised to identify which students are most likely to succeed.

Variations in structure of the outflow tract of the human embryonic heart: A new hypothesis for generating bicuspid aortic semilunar valves.

Outflow tract development of the heart is complex. The presence, differential growth and interactions of the various tissues through space and time contribute to the final development of the tract. This paper presents a novel interpretation of observations of outflow tract development, in particular of the aortic and pulmonary semilunar valves in embryos from the Shaner Collection at the University of Alberta. Three-dimensional reconstructions assist in the visualization of the spatial relationships of the developing valve tissues. In some embryos the aortic intercalated valve swelling is displaced proximally, giving rise to a bicuspid aortic semilunar valve more distally. In addition, the developing valve tissue first appears external to the myocardial cuff. The pulmonary semilunar valve regions appear to be more normal. This paper thus proposes a novel mechanism for generating a bicuspid aortic valve and also supports the idea that there is some independence of the aortic and pulmonary regions from each other during development.