An Exploratory Study of Educators' Perspectives Towards Hospital School Program Support for Children with Special Health Care Needs After Hospitalization.

More than 14 million children in the United States are identified as children with special healthcare needs (CSHCN). Rates of hospitalization for CSHCN with chronic conditions as well as re-admissions have been increasing in recent years. For hospitalized children transitioning back to their school of record, a host of issues may arise such as socioemotional concerns, peer rejection, and being behind in academics. Hospital-based school programs (HBSPs) play an important role in the transition back to a child's school of record. Utilizing a database of inpatient CSHCN at a midwestern children's hospital's HBSP, private and public-school educators associated with the previously hospitalized CSHCN were asked to complete an online survey to gather their perspectives related to the child's transition back to the school of record upon hospital discharge. Overall, educators' perspectives of the HBSP were positive while perceptions related to communication provided by the HBSP were mixed. Educators surveyed reported a lack of training related to working with CSHCN. Finally, accommodations and services offered to students upon return to school focused mostly on academic performance and attendance. Study limitations and implications for practice in schools are discussed.

Prior anatomy experience among medical students: What difference does it make?

Prior research has reported that experience in undergraduate anatomy did not significantly affect students' grades in professional schools, yet students would still recommend anatomy experience prior to medical school. It has been further posited that this prior experience may have benefits that do not appear in grade outcomes, such as decreased stress levels or different study strategies. The present study investigated whether different study strategies in anatomy were reported between students with and without prior experience. The data were collected using surveys administered near the beginning and the end of the medical anatomy course. The surveys included questions about study strategies used for the course, basic demographics, and prior experience in anatomy and/or physiology. Results confirmed very few differences in course outcomes between students with and without prior experience in anatomy and/or physiology; however, differences were noted in the study strategies reported. Students with prior experience in anatomy were more likely to report use of a wider variety of strategies and less changes in strategies between the surveys. However, these differences were only noted with prior courses of a certain number and level. It is posited that students with prior experience may have already created a basic scaffold of information in their mind that they could then plug additional information into rather than creating an entirely new knowledge structure. While this did not largely change course outcomes, it is likely to have positive effects on students' perceptions of stress and feelings of being overwhelmed during the course.

The IUSM Medical Education Scholarly Concentration: Training Medical Students to Become Future Clinical Educators.

Indiana University School of Medicine - Bloomington launched the Medical Education Scholarly Concentration in 2020. This application-based enrichment program trains medical students to become effective clinical educators through pedagogical coursework, introduction to education research methods, and the development of a scholarly concentration product for publication.

Do the benefits continue? Long term impacts of the Anatomy Education Research Institute (AERI) 2017.

BACKGROUND: The Anatomy Education Research Institute (AERI) was held in Bloomington, Indiana in July of 2017. Previous research has shown that AERI was successful in meeting Kirkpatrick's first two levels of evaluation via positive initial reactions and learning gains identified at the end of AERI. This manuscript demonstrates continued success in Kirkpatrick levels two and three via six-month and thirty-month follow-up surveys and nine-month follow-up focus groups and interviews. METHODS: Quantitative analyses were completed using Microsoft Excel (2019) and SPSS version 26 while qualitative analyses were completed for both survey responses and focus groups/interviews using thematic analyses. RESULTS: Results demonstrate that the learning gains seen immediately post-AERI 2017 were sustained for all participants (accepted applicants and invited speakers). Qualitative results continued to demonstrate positive reactions to AERI 2017. Both quantitative and qualitative results demonstrated that the main obstacle to educational research for most participants is time, while collaboration, IRB, institutional roadblocks, and devaluing of educational research were also identified as obstacles. CONCLUSIONS: The research presented here indicates positive outcomes to Kirkpatrick Levels 1, 2, & 3 of evaluation following AERI 2017. However, substantial obstacles still exist for researchers in medical education. The need for a sustained community of practice for educational researchers was suggested as a potential buffer against these obstacles and multiple options for providing that community are discussed.

Reaction of Pertechnetate in Highly Alkaline Solution: Synthesis and Characterization of the Nitridotrioxotechnetate Ba[TcO3 N].

The preparation of novel technetium oxides, their characterization and the general investigation of technetium chemistry are of significant importance, since fundamental research has so far mainly focused on the group homologues. Whereas the structure chemistry of technetium in strongly oxidizing media is dominated by the Tc O 4 - ${{\left[{\rm { Tc}}{{\rm { O}}}_{{\rm { 4}}}\right]}^{-}}$ anion, our recent investigation yielded the new Tc O 3 N 2 - ${{\left[{\rm { Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N}}\right]}^{{\rm { 2}}-}}$ anion. Brown single crystals of Ba[TcO3 N] were obtained under hydrothermal conditions starting from Ba(OH)2 ⋅ 8H2 O and NH4 [TcO4 ] at 200 °C. Ba [ Tc O 3 N ] ${{\rm { Ba[Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N]}}}$ crystallizes in the monoclinic crystal system with the space group P21 /n (a=7.2159(4) Å, b=7.8536(5) Å, c=7.4931(4) Šand ß=104.279(2)°). The crystal structure of Ba [ Tc O 3 N ] ${{\rm { Ba[Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N]}}}$ consists of isolated Tc O 3 N 2 - ${{\left[{\rm { Tc}}{{\rm { O}}}_{{\rm { 3}}}{\rm { N}}\right]}^{{\rm { 2}}-}}$ tetrahedra, which are surrounded by Ba2+ cations. XANES measurements complement the oxidation state +VII for technetium and Raman spectroscopic experiments on Ba[TcO3 N] single crystals exhibit characteristic Tc-O and Tc-N vibrational modes.

Solubility of Ca(II), Ni(II), Nd(III) and Pu(IV) in the presence of proxy ligands for the degradation of polyacrylonitrile in cementitious systems.

The solubility of Ca(OH)2(cr), ß-Ni(OH)2(cr), Nd(OH)3(s) and PuO2(ncr, hyd) was investigated in cement porewater solutions containing glutarate (GTA), α-hydroxyisobutarate (HIBA) and 3-hydroxybutarate (HBA). These ligands were proposed as probable degradation products of UP2W, a polyacrylonitrile-based filter aid used in nuclear power plants. Results obtained in this work are compared with reported solubility data in the presence of iso-saccharinic acid (ISA), a polyhydroxocarboxylic acid resulting from cellulose degradation. None of the investigated proxy ligands shows any significant impact on the solubility of Ca(II), Nd(III) or Pu(IV) in cement porewater solutions. Although the formation of binary complexes M-L (M = Ca(II), Nd(III), An(IV); L = GTA, HIBA, HBA) under acidic conditions is described in the literature, these organic ligands cannot outcompete hydrolysis under hyperalkaline conditions. GTA, HIBA and HBA induce a slight increase in the solubility of ß-Ni(OH)2(cr) at [L]tot = 0.1 M. This observation supports the formation of stable Ni(II)-GTA, -HIBA and -HBA complexes in hyperalkaline conditions, although the exact stoichiometry of these complexes remains unknown. The comparison of these results with solubility data in the presence of ISA confirms the stronger complexation properties of the latter ligand. Even though HIBA and HBA are carboxylic acids containing one alcohol group, this comparison shows that additional alcohol groups are required to efficiently chelate the metal ion and outcompete hydrolysis. This conclusion is supported by DFT calculations on the Pu(IV)-OH-L systems (L = GTA, HIBA and HBA), which indicate that the complexation with the proxy ligands takes places through the carboxylate group. XRD of selected solid phases after equilibration with proxy ligands at [L]tot = 0.1 M confirms that Ca(II), Ni(II), Nd(III) and Pu(IV) starting solid materials remained mostly unaltered in the course of the experiments. However, the presence of new XRD features suggests the possible formation of secondary phases. These results allow assessment of the effect of the proposed proxy ligands on the solubility of key radionuclides and metal ions in cementitious systems relevant for low and intermediate level waste, and feed into on-going sorption studies evaluating the impact of UP2W degradation products on the uptake of radionuclides by cement.

Construction of Knowledge Through Doing: A Brachial Plexus Model from Pipe Cleaners.

Medical students often struggle with the complexity of the brachial plexus, so instructions were developed for making a model of the brachial plexus from pipe cleaners following a didactic presentation of the material. Providing students the opportunity to construct the brachial plexus reduced cognitive overload, thus allowing students' working memory to attend to pertinent information and create mental schema of the structures. This activity allows the students to actively engage with the material and have a model from which to study with minimal cost requirements. The model was initially utilized in the final unit of a stand-alone gross anatomy course, followed closely by both a unit exam and a cumulative standardized exam. The following year, the curriculum was significantly changed so that the activity was presented during the first unit of the course followed closely by the unit exam and the cumulative final exam several months later. Students were surveyed on their opinions of the activity, perceived understanding of the material, and utilization of the model. Results demonstrated that students enjoyed the activity and felt it improved their understanding of the brachial plexus, especially in the second scenario. Students responded positively to the activity and felt that it would make a good study tool. In the second scenario, students also reported using the model to study throughout the semester. These results indicate that this low-cost model was helpful to the students, particularly if they need to study the material over an extended period of time. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40670-021-01274-2.

Changing Study Strategies with Revised Anatomy Curricula: a Move for Better or Worse?

Investigations into medical student study strategies have seen an increase in recent years, but we have also seen a move to more integrated medical curricula during this time. This manuscript endeavors to assess the changes in study plans and students' reported study strategies that are associated with a move from a traditional stand-alone anatomy curriculum to an integrated, standardized curriculum. Previously validated study strategy surveys were given to medical students at the beginning of their anatomy course and again at the end of the course. These responses were then correlated with basic demographic information and outcomes in anatomy. Results indicate that this change in curriculum does correlate with changes to students' study plans and reported study strategies. In particular, the plans for and use of web-based resources appear higher in the new curriculum while the use of self-quizzing and attendance appear lower, with potentially negative implications for understanding and long-term retention. Differences were also seen between genders and student ages. Finally, a few associations with outcomes are also noted for increased use of web-based resources and student confidence going into the exam.

Knowledge Gains and Changing Attitudes from the Anatomy Education Research Institute (AERI 2017): A Mixed Methods Analysis.

The inaugural Anatomy Education Research Institute (AERI 2017) was held in Bloomington, Indiana in July of 2017. This workshop style conference paired experienced educational researchers (invited speakers) with individuals interested in learning more about the field (accepted applicants). In 2017, AERI was held over a five-day period and entailed plenary style presentations, break-out sessions, and specific times for small group mentorship. All participants (applicants and invited speakers) completed a pre-conference survey at the beginning of the institute and a post-conference survey at the end of the institute. Both surveys included categorical and Likert scale questions as well as open-ended questions for participant feedback. Quantitative and qualitative analyses indicate that both applicants and speakers increased their knowledge of anatomy education research, but that additional obstacles remain. Funding, time, and a lack of respect for the field remain problematic for faculty that wish to complete educational research. Mentorship and a community of practice also emerged as major themes necessary for educational research to be successful.

Plans in Perspective: a Pilot Study of Medical Student Study Strategies in Physiology.

Students learn a great deal when they study course material outside of our classrooms, but we have little hard evidence of what they are actually doing during that time and how it varies over the course of the semester. This exploratory pilot study asked first-year medical students to complete study strategy surveys at the beginning and again at the end of a stand-alone physiology course. Responses to these surveys were then grouped into categories, and analyses were completed using above average and below average final grades in the course. The amount of change that occurred in individual student responses between pre-course and post-course surveys was also calculated. Results found that students with above average course grades were more likely to study with other students, make their own resources, and have lower grade expectations coming into the course than their peers with below average outcomes. Results also indicated that changing fewer study strategies may also be correlated with higher grades. Unfortunately, the sample sizes for this study are quite small, and additional data is unavailable locally due to curricular changes. It is hoped that other researchers may be able to further evaluate these ideas.

Another Nail in the Coffin for Learning Styles? Disparities among Undergraduate Anatomy Students' Study Strategies, Class Performance, and Reported VARK Learning Styles.

The concept and existence of learning styles has been fraught with controversy, and recent studies have thrown their existence into doubt. Yet, many students still hold to the conventional wisdom that learning styles are legitimate, and may adapt their outside of class study strategies to match these learning styles. Thus, this study aims to assess if undergraduate anatomy students are more likely to utilize study strategies that align with their hypothetical learning styles (using the VARK analysis from Fleming and Mills, , Improve Acad. 11:137-155) and, if so, does this alignment correlate with their outcome in an anatomy course. Relatedly, this study examines whether students' VARK learning styles are correlated with course outcomes regardless of the students' study strategies, and whether any study strategies are correlated with course outcomes, regardless of student-specific VARK results. A total of 426 anatomy students from the 2015 and 2016 Fall semesters completed a study strategies survey and an online VARK questionnaire. Results demonstrated that most students did not report study strategies that correlated with their VARK assessment, and that student performance in anatomy was not correlated with their score in any VARK categories. Rather, some specific study strategies (irrespective of VARK results), such as use of the virtual microscope, were found to be positively correlated with final class grade. However, the alignment of these study strategies with VARK results had no correlation with anatomy course outcomes. Thus, this research provides further evidence that the conventional wisdom about learning styles should be rejected by educators and students alike. Anat Sci Educ. © 2018 American Association of Anatomists.

Development and Implementation of the Inaugural Anatomy Education Research Institute (AERI 2017).

Education research is increasingly being recognized as a legitimate route for faculty development in universities. However, many anatomy faculty lack the appropriate training and access to experienced mentors who can help them develop their own education research projects. Inspired by the American Physiological Society's Institute for Teaching and Learning, the coauthors proposed and developed the inaugural Anatomy Education Research Institute (AERI 2017). Funded by an American Association of Anatomists Innovations grant, the five-day institute was held in Bloomington, Indiana in July 2017. The coauthors spent two years preparing the conference schedule, inviting speakers who could discuss education research topics and mentor applicants, reviewing applications, developing assessment instruments for the institute, and hosting the institute. A total of 62 registered participants (applicants and invited speakers) attended AERI 2017. Through a series of presentations and workshops, participants were introduced to many aspects of education research and the Scholarship of Teaching and Learning, including developing rigorous education research questions, determining appropriate methods to assess these questions, and searching the education research literature. Each day also included regular time devoted to work on their own education research project with help from more experienced mentors. Throughout the conference, participants were encouraged to post information on Twitter, using the hashtag #AERI2017. Participants had strong positive impressions of the conference and strongly requested future AERI conferences be held. Follow-up analyses will assess the institute in alignment with Kirkpatrick's Four Levels of Evaluation Model, though preliminary evaluation indicates AERI 2017 met the original aims of the proposal.

Thermodynamic description of Tc(iv) solubility and carbonate complexation in alkaline NaHCO3-Na2CO3-NaCl systems.

The solubility of 99Tc(iv) was investigated in dilute to concentrated carbonate solutions (0.01 M ≤ Ctot≤ 1.0 M, with Ctot = [HCO3-] + [CO32-]) under systematic variation of ionic strength (I = 0.3-5.0 M NaHCO3-Na2CO3-NaCl-NaOH) and pHm (-log[H+] = 8.5-14.5). Strongly reducing conditions (pe + pHm≈ 2) were set with Sn(ii). Carbonate enhances the solubility of Tc(iv) in alkaline conditions by up to 3.5 log10-units compared to carbonate-free systems. Solvent extraction and XANES confirmed that Tc was kept as +IV during the timeframe of the experiments (≤ 650 days). Solid phase characterization performed by XAFS, XRD, SEM-EDS, chemical analysis and TG-DTA confirmed that TcO2·0.6H2O(am) controls the solubility of Tc(iv) under the conditions investigated. Slope analysis of the solubility data in combination with solid/aqueous phase characterization and DFT calculations indicate the predominance of the species Tc(OH)3CO3- at pHm≤ 11 and Ctot≥ 0.01 M, for which thermodynamic and activity models are derived. Solubility data obtained above pHm≈ 11 indicates the formation of previously unreported Tc(iv)-carbonate species, possibly Tc(OH)4CO32-, although the likely formation of additional complexes prevents deriving a thermodynamic model valid for this pHm-region. This work provides the most comprehensive thermodynamic dataset available for the system Tc4+-Na+-Cl--OH--HCO3--CO32--H2O(l) valid under a range of conditions relevant for nuclear waste disposal.

Effects of community health interventions on under-5 mortality in rural Guinea-Bissau (EPICS): a cluster-randomised controlled trial.

BACKGROUND: Evidence suggests that community-based interventions that promote improved home-based practices and care-seeking behaviour can have a large impact on maternal and child mortality in regions where rates are high. We aimed to assess whether an intervention package based on the WHO Integrated Management of Childhood Illness handbook and community mobilisation could reduce under-5 mortality in rural Guinea-Bissau, where the health service infrastructure is weak. METHODS: We did a non-masked cluster-randomised controlled trial (EPICS) in the districts of Tombali and Quinara in Guinea-Bissau. Clusters of rural villages were stratified by ethnicity and distance from a regional health centre, and randomly assigned (1:1) to intervention or control using a computerised random number generator. Women were eligible if they lived in one of the clusters at baseline survey prior to randomisation and if they were aged 15-49 years or were primary caregivers of children younger than 5 years. Their children were eligible if they were younger than 5 years or were liveborn after intervention services could be implemented on July 1, 2008. In villages receiving the intervention, community health clubs were established, community health workers were trained in case management, and traditional birth attendants were trained to care for pregnant women and newborn babies, and promote facility-based delivery. Registered nurses supervised community health workers and offered mobile clinic services. Health centres were not improved. The control group received usual services. The primary outcome was the proportion of children dying under age 5 years, and was analysed in all eligible children up to final visits to villages between Jan 1 and March 31, 2011. This trial is registered with ISRCTN, number ISRCTN52433336. FINDINGS: On Aug 30, 2007, we randomly assigned 146 clusters to intervention (73 clusters, 5669 women, and 4573 children) or control (73 clusters, 5840 women, and 4675 children). From randomisation until the end of the trial (last visit by June 30, 2011), the intervention clusters had 3093 livebirths and the control clusters had 3194. 6729 children in the intervention group and 6894 in the control group aged 0-5 years on July 1, 2008, or liveborn subsequently were analysed for mortality outcomes. 311 (4·6%) of 6729 children younger than 5 years died in the intervention group compared with 273 (4·0%) of 6894 in the control group (relative risk 1·16 [95% CI 0·99-1·37]). INTERPRETATION: Our package of community-based interventions did not reduce under-5 mortality in rural Guinea-Bissau. The short timeframe and other trial limitations might have affected our results. Community-based health promotion and basic first-line services in fragile contexts with weak secondary health service infrastructure might be insufficient to reduce child deaths. FUNDING: Effective Intervention.

Study skills in anatomy and physiology: Is there a difference?

Many factors influence the way individual students study, including but not limited to: previous coursework, attitudes toward the class (motivation, intimidation, risk, etc.), metacognition, and work schedules. However, little of this research has involved medical students. The present article asks the question, "Do individual medical students study differently for different classes?" Study skills surveys were given to United States medical students at an allopathic medical school and an osteopathic medical school. Students were surveyed near the end of their first year gross anatomy course and again near the end of their first year physiology course. Survey items included Likert scale and open-ended questions about study habits and basic demographic information. The survey responses were correlated with each student's final grade percentages in the courses. Analysis revealed that the four most common study habits were reviewing lecture notes, taking practice examinations, completing learning exercises, and making drawings and diagrams. The two surveys (anatomy and physiology) from each individual were also compared to see if students reported different study habits in anatomy versus physiology. A negative correlation was found between changing study habits between courses and final anatomy grade percentages. Additional analyses suggest that those students who do change their study habits between courses are increasing the number of study strategies that they attempt. This increase in the number of study strategies attempted may not allow the student to reach the same depth of understanding as their colleagues who utilize fewer strategies.

Janus kinase 1/3 signaling pathways are key initiators of TH2 differentiation and lung allergic responses.

BACKGROUND: Janus kinases (JAKs) are regulators of signaling through cytokine receptors. The importance of JAK1/3 signaling on TH2 differentiation and development of lung allergic responses has not been investigated. OBJECTIVE: We sought to examine a selective JAK1/3 inhibitor (R256) on differentiation of TH subsets in vitro and on development of ovalbumin (OVA)-induced airway hyperresponsiveness (AHR) and inflammation in an experimental model of asthma. METHODS: A selective JAK1/3 inhibitor was used to assay the importance of this pathway on induction of TH1, TH2, and TH17 differentiation in vitro. In vivo, the effects of inhibiting JAK1/3 signaling were examined by administering the inhibitor during the sensitization or allergen challenge phases in the primary challenge model or just before provocative challenge in the secondary challenge model. Airway inflammation and AHR were examined after the last airway challenge. RESULTS: In vitro, R256 inhibited differentiation of TH2 but not TH1 or TH17 cells, which was associated with downregulation of signal transducer and activator of transcription (STAT) 6 and STAT5 phosphorylation. However, once polarized, TH2 cells were unaffected by the inhibitor. In vivo, R256 administered during the OVA sensitization phase prevented the development of AHR, airway eosinophilia, mucus hypersecretion, and TH2 cytokine production without changes in TH1 and TH17 cytokine levels, indicating that selective blockade of TH2 differentiation was critical. Inhibitor administration after OVA sensitization but during the challenge phases in the primary or secondary challenge models similarly suppressed AHR, airway eosinophilia, and mucus hypersecretion without any reduction in TH2 cytokine production, suggesting the inhibitory effects were downstream of TH2 cytokine receptor signaling pathways. CONCLUSIONS: Targeting the TH2-dependent JAK/STAT activation pathway represents a novel therapeutic approach for the treatment of asthma.

The Erasmus programme for postgraduate education in orthodontics in Europe: an update of the guidelines.

In 1989, the ERASMUS Bureau of the European Cultural Foundation of the Commission of the European Communities funded the development of a new 3-year curriculum for postgraduate education in orthodontics. The new curriculum was created by directors for orthodontic education representing 15 European countries. The curriculum entitled 'Three years Postgraduate Programme in Orthodontics: the Final Report of the Erasmus Project' was published 1992. In 2012, the 'Network of Erasmus Based European Orthodontic Programmes' developed and approved an updated version of the guidelines. The core programme consists of eight sections: general biological and medical subjects; basic orthodontic subjects; general orthodontic subjects; orthodontic techniques; interdisciplinary subjects; management of health and safety; practice management, administration, and ethics; extramural educational activities. The programme goals and objectives are described and the competencies to be reached are outlined. These guidelines may serve as a baseline for programme development and quality assessment for postgraduate programme directors, national associations, and governmental bodies and could assist future residents when selecting a postgraduate programme.

Three-dimensional analysis of initial biofilm formation on polytetrafluoroethylene in the oral cavity.

AIM: There is published evidence that polytetrafluoroethylene (PTFE) exhibits beneficial surface characteristics by means of long-term biofilm accumulation. The purpose of this study was to investigate and compare early biofilm formation on polytetrafluoroethylene, ceramic-reinforced polytetrafluoroethylene and as the control group, stainless steel. MATERIALS AND METHODS: This study comprised 10 healthy volunteers (5 females and 5 males) with a mean age of 27.3 ± 3.7 years. Three different slabs (two PTFE coatings: one pure and one ceramic-reinforced polytetrafluoroethylene, and stainless steel) were placed in random order on a splint in the mandibular molar region. Intraoral splints were inserted for 48 h. After 48 h, we removed the slabs from the splints and stained the biofilm with a two-color fluorescence assay for bacterial viability (LIVE/DEAD BacLight-Bacterial Viability Kit 7012, Invitrogen, Mount Waverley, Australia). The amount of biofilm accumulation was assessed using confocal laser scanning microscopy (CLSM). RESULTS: The biofilm surface coverage was 55.8 ± 39.8% on pure PTFE-coated probes, 55.9 ± 35.0% on ceramic-reinforced PTFE-coated probes, and 33.3 ± 37.8% on stainless steel. The differences among the three groups were not significant (p = 0.301). Biofilm depth was 5.6 ± 5.4 µm on pure PTFE-coated probes, 5.2 ± 3.8 µm on ceramic-reinforced PTFE-coated probes, and 2.4 ± 2.9 µm on stainless steel. The Friedman test revealed a significant difference in biofilm depth (p = 0.002). Pairwise comparison of biofilm accumulation yielded a significant difference between pure PTFE and ceramic-reinforced PTFE compared to stainless steel (p = 0.017; p = 0.005). CONCLUSION: Our results indicate that the beneficial surface characteristics of PTFE coatings by reducing long-term biofilm are not a result of inhibiting initial bacterial adhesion.

In the eye of the beholder: sex and race estimation using the human orbital aperture.

From the works of Broca and Krogman to modern-day Jantz and Buikstra, the orbit has been used for both quantitative and qualitative sex and race estimation. This study evaluates the practical value of these estimations. Orbital height and breadth were measured to determine the orbital index and assess differences between men and women or black people and white people in the Hamann-Todd Collection. Replicability of these measures was also examined. Finally, a geometric morphometric study was performed to assess shape differences using the entire margin. Significant differences were found in both the index and the geomorphometric study; however, further investigation revealed that the differences were of little practical use. The measurement differences were found to be smaller than intra-observer error, while the geometric morphometric analysis demonstrated that minimal percentage of variation in shape was attributable to group differences. Thus, these techniques should not be used to estimate sex or race.

Stress analysis of an all-ceramic FDP loaded according to different occlusal concepts.

The aim of this study was to investigate the influence of four different occlusal concepts on stress distribution in a four-unit fixed dental prosthesis (FDP) made of zirconia. A three-dimensional finite element (FE) model was created and four model versions with between 15 and 42 contact points were developed. A force of 300 N was distributed over the chewing surface according to the different occlusal concepts and virtually applied perpendicularly to the occlusal plane in each version. Then, FE analysis was performed and stress distribution evaluated. Generally, highest tensile stresses were located at the point of load application within the veneering layer and ranged from 104 to 204 MPa. The highest tensile stresses within the framework were located at the basal side of the connectors and ranged between 12 and 39 MPa. This study shows that the distribution of occlusal contact points significantly influences the stresses induced by occlusal forces in four-unit all-ceramic fixed dental prostheses and strongly suggests that the number and distribution of occlusal contacts may be important to minimise fatigue effects caused by cycling.