Dental Service and Resource Needs during COVID-19 among Underserved Populations.

INTRODUCTION: In response to the coronavirus disease 2019 (COVID-19) outbreak, dental services in British Columbia, Canada, were restricted to urgent and emergency cases between March 16 and May 18, 2020. It is unclear how the curtailment of oral health services has affected underserved populations who already often have limited access to dental care due to cost, fear, stigma, and discrimination. OBJECTIVES: To explore the experiences of underserved populations and their community organizations when accessing oral health services and information in British Columbia and identify their coping mechanisms employed during the curtailment of oral health care services. METHODS: Semistructured, remote interviews were conducted with 13 staff and 18 members from 6 community-based organizations. These organizations serve men and women with a history of incarceration and/or experiencing poverty and homelessness, persons living with human immunodeficiency virus/AIDS, adults living with mental illness, and older adults in long-term care facilities. The interviews were audio-recorded, transcribed verbatim, and coded for emerging themes using NVivo 12 software. Thematic analysis was performed. RESULTS: The pandemic raised concerns and hesitancy among underserved populations and further reduced access to care. In turn, those with unmet dental needs resorted to coping mechanisms, including turning to community support or medical services, self-management of dental issues, and not dealing with dental issues altogether. Community organizers and members outlined needed resources such as assistance navigating the dental care system, having a contact for dental-related questions, and member preparation for dental service changes, while emphasizing the importance of positive relationships with dental providers. CONCLUSION: Underserved populations who already face barriers to oral health care services experienced increased difficulty in addressing their oral health needs and concerns during the beginning of the COVID-19 pandemic. Strategies aimed at reaching out to this population and those who support them are needed to help mitigate negative coping strategies and increased oral health disparities. KNOWLEDGE TRANSFER STATEMENT: This study depicts ways of addressing unmet oral health-related issues during the COVID-19 pandemic for underserved populations and their community organizations with policy implications as well as practical strategies.

Pregnant women's perspectives on integrating preventive oral health in prenatal care.

BACKGROUND: Oral diseases are considered a silent epidemic including among pregnant women. Given the prevalence of oral conditions among pregnant women and the reported association with adverse pregnancy outcomes, there have been suggestions for the inclusion of preventive oral care in routine prenatal care. However, due to the different administrative and funding structure for oral health and prenatal care in Canada, progress towards this integration has been slow. Our study sought to qualitatively explore the views of pregnant women in British Columbia (BC) on the strategies for integrating preventive oral health care into prenatal care services. METHODS: A qualitative approach was utilized involving semi-structured interviews with fourteen (14) purposefully selected pregnant women in Vancouver and Surrey, BC. The interviews were audio-recorded and transcribed. The transcripts were analyzed using an inductive thematic approach. Study validity was ensured via memoing, field-notes, and member checking. RESULTS: Interviews ranged from 28 to 65 min producing over 140 pages of transcripts. Analysis resulted in three major themes: oral health experiences during pregnancy, perspectives on integration and integrated prenatal oral care, and strategies for addressing prenatal oral health care. A majority of participants were supportive of integrating preventive oral care in routine prenatal services, with referrals identified as a critical strategy. Oral health education was recognized as important before, during, and after pregnancy; oral health assessments should therefore be included in the prenatal care checklist. Limited funding was acknowledged as a barrier to oral health care access, which may explain why few participants visited their dentists during pregnancy. Interprofessional education surfaced as a bridge to provide prenatal oral health education. CONCLUSION: Pregnant women interviewed in this study support the inclusion of educational and preventive oral care during prenatal care, although their views differed on how such inclusion can be achieved in BC. They advocated the establishment of a referral system as an acceptable strategy for providing integrated prenatal oral health care.

High average power Q-switched 1314-nm two-crystal Nd:YLF laser.

A 1314 nm two-crystal Nd:YLF laser was designed and operated in both CW and actively Q-switched modes. Maximum CW output of 26.5 W resulted from 125 W of combined incident pump power. Active Q-switching was obtained by inserting a Brewster-cut acousto optic modulator. This setup delivered an average power of 18.6 W, with a maximum of 5.6 mJ energy per pulse with a pulse duration of 36 ns at a pulse repetition frequency of 500 Hz.

Variation of system performance, quality control standards and adherence to international FDG-PET/CT imaging guidelines. A national survey of PET/CT operations in Austria.

AIM: To gather information on clinical operations, quality control (QC) standards and adoption of guidelines for FDG-PET/CT imaging in Austrian PET/CT centres. METHODS: A written survey composed of 68 questions related to A) PET/CT centre and installation, B) standard protocol parameters for FDG-PET/CT imaging of oncology patients, and C) standard QC procedures was conducted between November and December 2013 among all Austrian PET/CT centres. In addition, a NEMA-NU2 2012 image quality phantom test was performed using standard whole-body imaging settings on all PET/CT systems with a lesion-to-background ratio of 4. Recovery coefficients (RC) were calculated for each lesion and PET/CT system. RESULTS: A) 13 PET/CT systems were installed in 12 nuclear medicine departments at public hospitals. B) Average fasting prior to FDG-PET/CT was 7.6 (4-12) h. All sites measured blood glucose levels while using different cut-off levels (64%: 150 mg/dl). Weight-based activity injection was performed at 83% sites with a mean FDG activity of 4.1 MBq/kg. Average FDG uptake time was 55 (45-75) min. All sites employed CT contrast agents (variation from 1%-95% of the patients). All sites reported SUV-max. C) Frequency of QC tests varied significantly and QC phantom measurements revealed significant differences in RCs. CONCLUSION: Significant variations in FDG-PET/CT protocol parameters among all Austrian PET/CT users were observed. Subsequently, efforts need to be put in place to further standardize imaging protocols. At a minimum clinical PET/CT operations should ensure compliance with existing guidelines. Further, standardized QC procedures must be followed to improve quantitative accuracy across PET/CT centres.

High average power 1314 nm Nd:YLF laser, passively Q-switched with V:YAG.

A 1314 nm Nd:YLF laser was designed and operated both CW and passively Q-switched. Maximum CW output of 10.4 W resulted from 45.2 W of incident pump power. Passive Q-switching was obtained by inserting a V:YAG saturable absorber in the cavity. The oscillator delivered a maximum of 825 µJ energy per pulse, with a pulse duration of 135 ns at a pulse repetition frequency of 6.3 kHz, effectively delivering 5.2 W of average power.

Influence of PET reconstruction parameters on the TrueX algorithm. A combined phantom and patient study.

UNLABELLED: With the increasing use of functional imaging in modern radiotherapy (RT) and the envisaged automated integration of PET into target definition, the need for reliable quantification of PET is growing. Reconstruction algorithms in new PET scanners employ point-spread-function (PSF) based resolution recovery, however, their impact on PET quantification still requires thorough investigation. PATIENTS, MATERIAL, METHODS: Measurements were performed on a Siemens PET/CT using an IEC phantom filled with varying activity. Data were reconstructed using the OSEM (Gauss filter) and the PSF TrueX (Gauss and Allpass filter) algorithm with all available products of iterations (i) and subsets (ss). The recovery coeffcient (RC) and threshold defining the real sphere volume were determined for all settings and compared to the clinical standard (4i21ss). PET acquisitions of eight lung patients were reconstructed using all algorithms with 4i21ss. Volume size and tracer uptake were determined with different segmentation methods. RESULTS: The threshold for the TrueX was lower (up to 40%) than for the OSEM. The RC for the different algorithms and filters varied. TrueX was more sensitive to permutations of i and ss and only the RC of the OSEM stabilised with increasing number. For patient scans the difference of the volume and activity between TrueX and OSEM could be reduced by applying an adapted threshold and activity correction. CONCLUSION: The TrueX algorithm results in excellent diagnostic image quality, however, guidelines for native algorithms have to be extended for PSF based reconstruction methods. For appropriate tumour delineation, for the TrueX a lower threshold than the 42% recommended for the OSEM is necessary. These filter dependent thresholds have to be verified for different scanners prior to using them in multicenter trials.

Validation for 2D/3D registration. I: A new gold standard data set.

PURPOSE: In this article, the authors propose a new gold standard data set for the validation of two-dimensional/three-dimensional (2D/3D) and 3D/3D image registration algorithms. METHODS: A gold standard data set was produced using a fresh cadaver pig head with attached fiducial markers. The authors used several imaging modalities common in diagnostic imaging or radiotherapy, which include 64-slice computed tomography (CT), magnetic resonance imaging using T1, T2, and proton density sequences, and cone beam CT imaging data. Radiographic data were acquired using kilovoltage and megavoltage imaging techniques. The image information reflects both anatomy and reliable fiducial marker information and improves over existing data sets by the level of anatomical detail, image data quality, and soft-tissue content. The markers on the 3D and 2D image data were segmented using ANALYZE 10.0 (AnalyzeDirect, Inc., Kansas City, KN) and an in-house software. RESULTS: The projection distance errors and the expected target registration errors over all the image data sets were found to be less than 2.71 and 1.88 mm, respectively. CONCLUSIONS: The gold standard data set, obtained with state-of-the-art imaging technology, has the potential to improve the validation of 2D/3D and 3D/3D registration algorithms for image guided therapy.

A compact streak camera for 150 fs time resolved measurement of bright pulses in ultrafast electron diffraction.

We have developed a compact streak camera suitable for measuring the duration of highly charged subrelativistic femtosecond electron bunches with an energy bandwidth in the order of 0.1%, as frequently used in ultrafast electron diffraction (UED) experiments for the investigation of ultrafast structural dynamics. The device operates in accumulation mode with 50 fs shot-to-shot timing jitter, and at a 30 keV electron energy, the full width at half maximum temporal resolution is 150 fs. Measured durations of pulses from our UED gun agree well with the predictions from the detailed charged particle trajectory simulations.

Efficient implementation of the rank correlation merit function for 2D/3D registration.

A growing number of clinical applications using 2D/3D registration have been presented recently. Usually, a digitally reconstructed radiograph is compared iteratively to an x-ray image of the known projection geometry until a match is achieved, thus providing six degrees of freedom of rigid motion which can be used for patient setup in image-guided radiation therapy or computer-assisted interventions. Recently, stochastic rank correlation, a merit function based on Spearman's rank correlation coefficient, was presented as a merit function especially suitable for 2D/3D registration. The advantage of this measure is its robustness against variations in image histogram content and its wide convergence range. The considerable computational expense of computing an ordered rank list is avoided here by comparing randomly chosen subsets of the DRR and reference x-ray. In this work, we show that it is possible to omit the sorting step and to compute the rank correlation coefficient of the full image content as fast as conventional merit functions. Our evaluation of a well-calibrated cadaver phantom also confirms that rank correlation-type merit functions give the most accurate results if large differences in the histogram content for the DRR and the x-ray image are present.

Gastric emptying of glucose solution and associated plasma concentrations of GLP-1, GIP, and PYY before and after fundoplication.

BACKGROUND: This study was designed to assess the relationship between gastric emptying of glucose solution and the ensuing plasma concentrations of glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and glucose-dependent insulinotropic polypeptide (GIP) in patients having undergone fundoplication for gastroesophageal reflux (GERD). SUBJECTS AND METHODS: In 10 male patients the emptying of 50% glucose solution was determined scintigraphically and its relationship with plasma glucose, GLP-1, PYY, and GIP concentrations was studied before and 3 months after fundoplication. RESULTS: In the first 30 min after glucose ingestion, emptying was significantly (p = 0.048) faster after fundoplication than before. Emptying and GLP-1 and GIP correlated: the faster the emptying during the first 30 min the greater the concentrations integrated over that period (p = 0.04; p = 0.01; p = 0.02). Emptying and PYY concentrations were unrelated. In the 120-180 min. period, blood glucose concentrations were lower the faster the emptying in the initial 30 min (p = 0.06) and the entire 50-min recording period (p = 0.03) had been. The GLP-1 concentrations integrated over the first 30 min correlated inversely with the integrated plasma glucose during the third hour after ingestion (p = 0.004). CONCLUSIONS: After fundoplication, gastric emptying may, if accelerated in its initial phases, give rise to greater and earlier increases in plasma glucose, GLP-1, and GIP concentrations and thus to reactive hypoglycemia.

Effects of essential oils from fennel (Foeniculi aetheroleum) and caraway (Carvi aetheroleum) in pigs.

The ban of antibiotics as a feed additive requires alternatives to stabilize the health and performance particularly of the young animals. Essential oils obtained from fennel seed (Foeniculi aetheroleum) and caraway seed (Carvi aetheroleum) were tested in diets for weaned piglets in comparison with either a diet without feed additive or with a combination of formic acid and copper (positive control). Four groups of sixteen piglets (live weight 7 kg, age 26 days) received diets without (1) or with supplements of 7.5 g formic acid + 160 mg Cu/kg (2), 100 mg fennel oil/kg (3) or 100 mg caraway oil/kg (4) during 3 weeks after weaning. In the subsequent 4 weeks, all piglets were fed a diet without these additions. Fennel oil contained almost 2/3 anethol, approximately 1/5 fenchon and the remaining part consisting of alpha + beta-pinen, limonen (p-mentha-1,8-dien) and estragol. In the caraway oil, half of the contents was represented by limonen and the other half by carvon. There were no piglet losses and only few cases of diarrhoea. The combination of formic acid and copper increased feed consumption by 27% and daily weight gain by 25%. There were no differences in the performance between the group fed fennel oil and the control without additives. Piglets fed caraway oil tended to consume less feed and to gain approximately 10% less. In feed choice experiments, pigs consumed the same two diets from two troughs with 50% of total feed amount, as expected. The diets containing fennel or caraway oils were consumed at less than 50%. If the diet contained 100 mg fennel oil/kg, the decrease of percentual feed intake was significant. The results of the feeding experiment and of the feed choice experiment question the classification of fennel and caraway oils as flavour additives or as 'appetite promoters' in diets for weaned piglets.

Evaluation of a new electromagnetic tracking system using a standardized assessment protocol.

This note uses a published protocol to evaluate a newly released 6 degrees of freedom electromagnetic tracking system (Aurora, Northern Digital Inc.). A practice for performance monitoring over time is also proposed. The protocol uses a machined base plate to measure relative error in position and orientation as well as the influence of metallic objects in the operating volume. Positional jitter (E(RMS)) was found to be 0.17 mm +/- 0.19 mm. A relative positional error of 0.25 mm +/- 0.22 mm at 50 mm offsets and 0.97 mm +/- 1.01 mm at 300 mm offsets was found. The mean of the relative rotation error was found to be 0.20 degrees +/- 0.14 degrees with respect to the axial and 0.91 degrees +/- 0.68 degrees for the longitudinal rotation. The most significant distortion caused by metallic objects is caused by 400-series stainless steel. A 9.4 mm maximum error occurred when the rod was closest to the emitter, 10 mm away. The improvement compared to older generations of the Aurora with respect to accuracy is substantial.

Fast DRR generation for 2D/3D registration.

We present a simple and rapid method for generation of perspective digitally rendered radiographs (DRR) for 2D/3D registration based on splat rendering. Suppression of discretization artefacts by means of computation of Gaussian footprints--which is a considerable computational burden in classical splat rendering--is replaced by stochastic motion of either the voxels in the volume to be rendered, or by simulation of a X-ray tube focal spot of finite size. The result is a simple and fast perspective rendering algorithm using only a small subset of voxels. Our method generates slightly blurred DRRs suitable for registration purposes at framerates of approximately 10 Hz when rendering volume images with a size of 30 MB on a standard PC.

[Pitfalls and complications of elastic stable intramedullary nailing (ESIN) of femoral fractures in infancy]. / Pitfalls und Komplikationen der elastisch stabilen intramedullären Nagelung (ESIN) von Femurfrakturen im Kindesalter.

BACKGROUND: The aim of this prospective study was to evaluate the intra- and postoperative problems as well as the complications of elastic stable intramedullary nailing (ESIN) of femur fractures in children. PATIENTS AND METHODS: 47 consecutive children, mean age 6 years, were reviewed clinically and radiologically until hardware removal and after this annually. Mean time of follow up was 37 months. RESULTS: Intraoperatively one cortex perforation and one displacement of a third fragment occurred. Two correction operations were necessary: In one case due to an implant displacement and in another case due to an unacceptable loss of reduction. There were no infections, non union, implant breakage, refracture or disturbance of growth. CONCLUSIONS: ESIN is a safe procedure in femoral shaft fractures of children. Most of the problems and complications can be avoided by a careful consideration of the indication and a correct operation technique.

Elastic stable intramedullary nailing of midclavicular fractures in athletes.

BACKGROUND: Intramedullary fixation of midclavicular fractures may be a better option than non-operative treatment for high performance/professional athletes because of the potential reduction in recovery time. OBJECTIVES: To evaluate the effectiveness of intramedullary fixation in high performance athletes and the time required to return to sporting activity. METHODS: Data were taken from a prospective study on intramedullary fixation techniques using the elastic stable Ti nail (TEN, Synthes) for the treatment of displaced midclavicular fractures, initiated in 1996. The patients in 12 cases were classified as high performance/professional athletes. These cases were used to evaluate the technique specifically in this population. Fractures were classified according to the Orthopaedic Trauma Association (OTA) system. Patients were evaluated before and after surgery for shoulder function and subjective pain. After the operation, radiological assessments documented fracture healing, and clinical outcomes scores were obtained. Time required to return to training and competition was documented. RESULTS: All fractures were transverse or oblique. Mean (SD) shoulder abduction increased from 36.3 (8) degrees before surgery to 154.2 (17) degrees afterwards (p<0.001). Mean subjective pain score using a visual analogue scale (0-100) decreased from 71.7 (18) points before surgery to 19.2 (6) points (p<0.001) three days after. There were no complications. Hospital stay averaged 2.9 (1) days. Mean delay to resumption of training was 5.9 (1) days, and to resumption of competition it was 16.8 (5) days. The mean Constant clinical outcomes score one year after hardware removal was 98.3 (2) points. CONCLUSIONS: Intramedullary fixation of displaced midclavicular fracture was successful in terms of clinical outcome and rapid resumption of sporting activities. This treatment should be offered to athletes as an alternative to non-operative treatment.

[Thiocyanate--a biologically active ion of veterinary and medical relevance]. / Thiocyanat--ein biologisch aktives Ion von veterinärmedizinischer und medizinischer Relevanz.

Thiocyanate-ions are ubiquitous in living nature. They are important for the cell-function and the ongoing of vital functions. Therefore they are an essential factor in both, animal and human being. The Thiocyanate-ions are brought in alimentary but also built by the organism itself. Beneath the guarantee for many different body-functions Thiocyanate-ions are an important part of the immune response. To that belongs their involvement in H2O2-Thiocyanate Peroxidase-Systems. Furthermore Thiocyanate-ions are agents for cell-protection and for the repair-mechanism of the host in the struggle with toxic substances of germs. Therefore they also have a tumour-prophylactic effect. Thiocyanate-ions participate at physiochemical reactions which due the protein-conformation. There are hypothesis that a deficiency of Thiocyanate-ions may be a co-factor for causative agents of diseases such as Cystic Fibrosis and Transmissible Spongiform Encephalopathia. References for calculations of the alimentary balance are given, if deficiency of Thiocyanate-ions occurs. From the view of an optimal animal-feeding the sufficient alimentary supply of Thiocyanate-ions and their precursors is mentioned.

Conceptional considerations for a German influenza pandemic preparedness plan.

A pandemic appearance of influenza A virus must be expected at any time. The limitations of health preserving and life-saving resources, which will inevitably be reached in the event of a pandemic, will be accompanied by ethical and possibly social conflicts, which can be lessened or resolved only through precautionary planning, clearly specified competencies and transparent decisions within a social consensus. In case of a shortage of vaccines and virostatic agents, decisions will have to be made with regard to the segment of the population that absolutely must be vaccinated. It is currently estimated that a (monovalent) vaccine developed for a new pandemic strain would only suffice for the single vaccination of approximately half of the German population after a year; only 10-14 million vaccine dosages would be available to provide basic immunization and single boosters to personnel required to maintain basic medical care and essential infrastructure after half a year. In the event of local influenza outbreaks, antiviral chemotherapeutic agents could be used to close the gap until a vaccine can become effective. Even if suitable influenza vaccines and virostatic agents are not sufficiently available at the start of a pandemic, it is still possible to at least prevent an outbreak of two of the most feared secondary infections that accompany influenza: pneumococcal pneumonia or meningitis and illnesses resulting from Haemophilus influenzae. Agreement still needs to be reached with manufacturers for guaranteeing the necessary vaccine production or ensuring that they have a sufficient stock to meet the minimum demand for antiviral agents and agents for symptomatic treatment.

Influenza pandemic: preparedness planning in Germany.

The following conceptual framework formed the basis for a common decision made by the health ministers of Germany's 16 federal states to set up an influenza pandemic preparedness plan. The worst case scenario was used, on the basis of the data from the pandemic of 'Spanish flu', in 1918-20. The priority groups for vaccination were assessed, as well as the potentially available antiviral treatments. National policies could be highly improved by a common European view.

Computer-enhanced stereoscopic vision in a head-mounted display for oral implant surgery.

We developed a head-mounted display (HMD) with integrated computer-generated stereoscopic projection of target structures and integrated it into visit, a specific oral implant planning and navigation software. The HMD is equipped with two miniature computer monitors that project computer-generated graphics stereoscopically into the optical path. Its position is tracked by the navigation system's optical tracker and target structures are displayed in their true position over the operation site. In order to test this system's accuracy and spatial perception of the viewer, five interforaminal implants in three dry human mandibles were planned with visit and executed using the stereoscopic projection through the HMD. The deviation between planned and achieved position of the implants was measured on corresponding computed tomography (CT) scan images recorded post-operatively. The deviation between planned and achieved implant position at the jaw crest was 0.57 +/- 0.49 mm measured from the lingual, and 0.58 +/- 0.4 mm measured from the buccal cortex. At the tip of the implants the deviation was 0.77 +/- 0.63 mm at the lingual and 0.79 +/- 0.71 mm at the buccal cortex. The mean angular deviation between planned and executed implant position was 3.55 +/- 2.07 degrees. The present in vitro experiment indicates that the concept of preoperative planning and transfer to the operative field by an HMD allows us to achieve an average precision within 1 mm (range up to 3 mm) of the implant position and within 3 degrees deviation for the implant inclination (range up to 10 degrees ). Control during the drilling procedure is significantly improved by stereoscopic vision through the HMD resulting in a more accurate inclination of the implants.