Biomechanical performance of an immature maxillary central incisor after revitalization: a finite element analysis.

AIM: To investigate the stress distribution in an immature maxillary incisor and the same tooth after simulated revitalization with deposition of tubular dentine or cementum by finite element analysis (FEA). METHODOLOGY: A finite element model of a maxillary central incisor was developed on the basis of a µCT scan. The tooth was segmented in two parts: a part that represented a tooth in an immature state and an apical part that represented the tissue formed after revitalization. The apical part was given the mechanical properties of dentine or cementum. The immature tooth and the same tooth reinforced by either dentine or cementum underwent simulation of biting, trauma and orthodontic movement. Von Mises stress values were compared between the scenarios and tooth segments. RESULTS: Maximum stress in the immature incisor developed apically; however, dentine- and cementum-reinforced teeth revealed the greatest stress in the external portion of the root decreasing towards the apex. Greatest mechanical stress was caused by dental trauma perpendicular to the long axis of the root followed by biting and orthodontic movement. Stress peaks were lower in the dentine-reinforced tooth compared with the cementum-reinforced tooth in all scenarios; however, median stress in the immature part was reduced irrespective of dentine or cementum deposition. Dentine reinforcement caused greater stress values in the apical segment due to absorbance of the applied force, whereas stress was not transferred towards deposited cementum. CONCLUSIONS: Apposition of simulated hard tissue in a maxillary central incisor after revitalization reduced mechanical stress in the immature tooth. Formation of dentine was advantageous because, unlike cementum, it facilitated an even stress distribution throughout the root resulting in lower stress values.

An exercise programme for community-dwelling, mobility-restricted and chronically ill older adults with structured support by the general practitioner's practice (HOMEfit). From feasibility to evaluation.

Programmes containing health-enhancing physical exercise should be evaluated using standards that are just as rigorous as those required for drug development. In contrast to new medicines, exercise programmes are highly complex. This has to be taken into account when designing the research plan. In order to illustrate the development process of a "complex intervention", we use the example of an exercise programme for community-dwelling, mobility-restricted and chronically ill older adults. Based on a framework for evaluation of complex interventions (Medical Research Council [MRC], UK), a research plan was set up containing the phases: development, feasibility, evaluation, implementation. The development phase resulted in the design of a home-based exercise programme in which the target group is approached and supported via their general practitioner and an exercise therapist. A feasibility study was performed. Three quantitative criteria for feasibility (adoption, safety, continuing participation) were statistically confirmed which permitted the decision to proceed with the research plan. So far, the MRC framework has proved to be valuable for the development of the new programme.

[Prerequisites for a new health care model for elderly people with multiple morbidities: results and conclusions from 3 years of research in the PRISCUS consortium]. / Voraussetzungen für ein neues Versorgungsmodell für ältere Menschen mit Multimorbidität: Ergebnisse und Schlussfolgerungen aus 3-jähriger Forschung im PRISCUS-Verbund.

BACKGROUND: The concurrent presence or manifestation of multiple chronic conditions, i.e. multimorbidity, poses a challenge to affected patients and their relatives, physicians, and practitioners, and to the health care system in general. Aiming to improve medical care for different chronic diseases, the Chronic Care Model also appears to be suited for multimorbidity. The established research consortium PRISCUS is trying to create some of the prerequisites for a new care model for multimorbid, elderly patients oriented along the lines of the Chronic Care Model. METHODS AND RESULTS: Four out of seven subprojects of the research consortium provide an overview of some of their findings. Topics in a sports medicine subproject were the assessment of physical activity by means of a newly developed questionnaire and the development and feasibility testing of an exercise program for elderly people with chronic conditions and mobility impairment. Partners from family medicine implemented geriatric assessment in a primary care setting and evaluated its consequences. In a pharmacological subproject, potentially inappropriate medication as well as drug-drug interactions and dosing errors were addressed. The health economic subproject investigated quality of life impairment due to multiple chronic diseases and the effects of multimorbidity on costs. CONCLUSIONS: The results of the PRISCUS research consortium allow a better description of consequences of multimorbidity and illustrate at least some new approaches towards prevention, diagnosis, and treatment of patients suffering from multimorbidity. Ongoing projects will test the efficacy of a physical activity program and a new complex intervention to reduce potentially inappropriate medication in the elderly. With this, the research consortium will create some prerequisites for a new health care model for patients with multimorbidity comparable to the Chronic Care Model.

Knowledge and attitudes of dentists regarding traumatic dental injuries.

AIM: The aim of this study was to evaluate the knowledge levels of dentists regarding the treatment of several dental injuries. METHODS: Study design: Cross-sectional study. A structured questionnaire was validated and sent electronically to the Professional Dental Schools of each Spanish region and subsequently to the affiliated dentists. The survey collected the dentists' demographic data and asked 11 questions regarding traumatic dental injuries and their potential complications and treatments. The relationships between the demographic data and the correct/incorrect answers regarding dental injuries were estimated by means of Pearson's chi-squared test and post hoc testing. RESULTS: The survey was answered by 1532 dentists. None of the demographic variables was related to better knowledge. However, men, older dentists and more experienced dentists were related to having a self- evaluation of knowledge as comprehensive; 64.1% of the answers given by the respondents were correct. Surprisingly, having more clinical dental experience and a postgraduate degree were not related to better knowledge. The results revealed an uneven knowledge among dentists depending on the type of dental trauma injury. Questions on treatment of avulsion of immature teeth and complicated fractures had a correct answer frequency higher than 70%, while questions regarding intrusion and lateral luxation had a knowledge lower than 60% and less than 30%, respectively. More than 50% of dentists would apply splinting after replantation for more than 14 days. CONCLUSION: Dentists need to improve their knowledge regarding the treatment of tooth intrusion, lateral luxation and avulsion of mature teeth as well as the use of splinting.

Caracterización de los componentes óseos de la articulación temporomandibular: una revisión de la literatura / Characterization of bone components of the temporomandibular joint: a literature review

La articulación temporomandibular (ATM) es una articulación sinovial bilateral de tipo ginglimo-artroidal que anatómicamente está conformada por el cóndilo mandibular, fosa mandibular y tubérculo articular. Es necesario tener un acabado conocimiento de la anatomía de la ATM para una correcta comprensión de su funcionamiento. La descripción anatómica de las estructuras óseas presente en la literatura científica, y que componen la ATM, no es del todo exacta, con diversas diferencias sobre la delimitación del cóndilo mandibular, las fisuras presentes en la fosa mandibular y las superficies articulares de la fosa mandibular y tubérculo articular, así como una amplia variabilidad de términos para referirse a cada estructura anatómica. Se realizó una revisión sistemática de textos y artículos científicos sobre la descripción anatómica de los componentes óseos de la ATM y los términos para referirse a ellos, comparándolos con los términos establecidos por la Terminología Anatómica Internacional.

The temporomandibular joint (TMJ) is a ginglymus-arthrodial bilateral synovial joint, anatomically composed by the mandibular condyle, mandibular fossa and articular tubercle. It is necessary to have a perfect knowledge of the anatomy of the TMJ for a proper understanding of its function. The anatomical description of bony structures of the TMJ present in the scientific literature is not entirely accurate, with several differences on the delimitation of the mandibular condyle, the limits of the articular surfaces, the fissures present in the mandibular fossa. In addition, there is a wide variability of terms for each anatomical structure. A review of textbooks and scientific articles was performed, about the anatomical description of the bony components of the TMJ and terms to refer to them, compared with the terms established by the Anatomical Terminology.