To what extent can mastication functionality be restored following mandibular reconstruction surgery? A computer modeling approach.

STATEMENT OF PROBLEM: Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs. PURPOSE: To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function. MATERIAL AND METHODS: We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation. RESULTS: We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%. CONCLUSION: These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.

Estimating tongue deformation during laryngoscopy using a hybrid FEM-multibody model and intraoperative tracking - a cadaver study.

Throat tumour margin control remains difficult due to the tight, enclosed space of the oral and throat regions and the tissue deformation resulting from placement of retractors and scopes during surgery. Intraoperative imaging can help with better localization but is hindered by non-image-compatible surgical instruments, cost, and unavailability. We propose a novel method of using instrument tracking and FEM-multibody modelling to simulate soft tissue deformation in the intraoperative setting, without requiring intraoperative imaging, to improve surgical guidance accuracy. We report our first empirical study, based on four trials of a cadaveric head specimen with full neck anatomy, yields a mean TLE of 10.8 ± 5.5 mm, demonstrating methodological feasibility.

Angle Kappa Influence on Multifocal IOL Outcomes.

PURPOSE: To characterize angle kappa and study the relationship between preoperative angle kappa and postoperative refractive accuracy, visual outcomes, and patient satisfaction in a large population of eyes with multifocal intraocular lens (MIOL) implantation. METHODS: A comprehensive electronic medical record chart review of 26,470 consecutive eyes that underwent immediate sequential bilateral cataract or refractive lens exchange with MIOLs was conducted. The primary outcome measures were postoperative monocular uncorrected distance visual acuity (UDVA), manifest refraction sphere and cylinder, spherical equivalent (SEQ), defocus equivalent (DEQ), subjective quality of vision at near, intermediate, and distance, and the likelihood of recommending the procedure. Relationships between preoperative angle kappa and postoperative outcomes were assessed with Pearson correlations. RESULTS: Angle kappa followed a right-skewed normal distribution (R2 = 0.99) with a mean ± standard deviation of 0.64 ± 0.27 mm. No clinically meaningful relationship was found between preoperative angle kappa and postoperative sphere, cylinder, SEQ, and DEQ, all with R2 ⩽ 0.0005. Similarly, there was no clinically meaningful relationship between preoperative angle kappa and postoperative UDVA (R2 = 0.001), postoperative satisfaction for near, intermediate, and distance vision (all R2 ⩽ 0.0023), or for recommending the MIOL surgery to friends and relatives (R2 = 0.0000). CONCLUSIONS: Preoperative angle kappa does not have a predictive clinical impact on postoperative MIOL visual outcomes, refractive accuracy, or subjective patient satisfaction. Angle kappa as a single variable cannot be used to determine MIOL candidacy. [J Refract Surg. 2023;39(12):840-849.].

The Simons Observatory: A fully remote controlled calibration system with a sparse wire grid for cosmic microwave background telescopes.

For cosmic microwave background (CMB) polarization observations, calibration of detector polarization angles is essential. We have developed a fully remote controlled calibration system with a sparse wire grid that reflects linearly polarized light along the wire direction. The new feature is a remote-controlled system for regular calibration, which has not been possible in sparse wire grid calibrators in past experiments. The remote control can be achieved by two electric linear actuators that load or unload the sparse wire grid into a position centered on the optical axis of a telescope between the calibration time and CMB observation. Furthermore, the sparse wire grid can be rotated by using a motor. A rotary encoder and a gravity sensor are installed on the sparse wire grid to monitor the wire direction. They allow us to achieve detector polarization angle calibration with an expected systematic error of 0.08°. The calibration system will be installed in small-aperture telescopes at Simons Observatory.

Seasonal patterns of bird and bat collision fatalities at wind turbines.

Information on when birds and bats die from collisions with wind turbines can help refine efforts to minimize fatalities via curtailment of energy productions and can offer insight into the risk factors associated with collision fatalities. Using data pooled from 114 post-construction monitoring studies conducted at wind facilities across the United States, we described seasonal patterns of fatalities among birds and bats. Bat fatalities peaked in the fall. Silver-haired bat (Lasionycteris noctivagans), a long-distance migrant, and Mexican free-tailed bat (Tadarida brasiliensis) both showed maximum fatality counts later in the year-October and November, respectively-than any other bat species. The other common species in our sample-hoary bat (Aeorestes cinereus), Eastern red bat (Lasiurus borealis), and big brown bat (Eptesicus fuscus)-showed broadly overlapping peaks of fatality counts in August. Fatalities of silver-haired bat showed a smaller spring peak in some ecoregions; no other bat species exhibited this pattern. Seasonal patterns of bird fatalities varied among guilds. Woodland birds, many of which were long-distance migrants, showed two peaks in fatalities corresponding to spring and fall migration. Grassland birds and soaring birds, most of which were resident or short-distance migrants, did not exhibit strong seasonal peaks in fatalities. Species in these guilds tend to inhabit regions with extensive wind-energy development year-round, which may explain the more consistent numbers of fatalities that we observed. Our results highlight the value of pooling data to develop science-based solutions to reduce conflicts between wind-energy development and wildlife but also emphasize the need for more extensive data and standardization of post-construction monitoring to support more robust inferences regarding wind-wildlife interactions and collision risk.

Toric Trifocal Intraocular Lens for Refractive Lens Exchange: A Multi-center, Multi-surgeon Large Cohort Study.

PURPOSE: To assess the outcomes of a novel toric trifocal intraocular lens (IOL) for refractive lens exchange (RLE) in a large series of eyes with corneal astigmatism. METHODS: Consecutive eyes that underwent RLE with the PanOptix Toric IOL (Alcon Laboratories, Inc) were included. Outcomes measures included postoperative distance (UDVA), 60 cm intermediate (UIVA), and 40 cm near (UNVA) uncorrected visual acuity, manifest refraction, spherical and defocus equivalent, efficacy and safety indices, and vector analyses of refractive and toric IOL accuracy. RESULTS: A total of 4,933 eyes had a median follow-up of 3 months. UDVA of 20/20 and 20/40 was obtained in 65% and 99% of eyes monocularly and 87% and 100% binocularly, respectively. UIVA at 60 cm of 20/25 and 20/40 was achieved in 70% and 99% of eyes monocularly and in 77% and 100% binocularly, respectively. UNVA at 40 cm of 20/25 and 20/40 was achieved in 85% and 96% of eyes monocularly and in 95% and 100% binocularly, respectively. A total of 67%, 89%, 97%, and 99% of eyes had a SEQ within 0.25, 0.50, 0.75, and 1.00 diopter (D) of intended target (R2 = 0.99). Postoperative refractive astigmatism of 0.50, 0.75, and 1.00 D or less was achieved in 86%, 95%, and 98% of eyes. The vector analysis correction index and index of success were 1.04 ± 0.35 and 0.41 ± 0.31 for toric IOL accuracy and 1.00 ± 0.46 and 0.36 ± 0.55 for refractive accuracy, respectively. The 3- and 12-month post-RLE excimer laser enhancement rates were 1.1% (95% CI: 0.8% to 1.4%) and 7.6% (95% CI: 6.9% to 8.3%), respectively. CONCLUSIONS: The PanOptix Toric IOL performed well for a wide range of axial lengths and corneal astigmatism in eyes that had RLE. Most patients achieved effective uncorrected binocular near, intermediate, and distance vision for daily functioning. [J Refract Surg. 2023;39(5):302-310.].

Prediction accuracy of intraoperative aberrometry compared with preoperative biometry formulae for intraocular lens power selection.

OBJECTIVE: To compare the accuracy of intraoperative wavefront aberrometry to preoperative biometry formulae for predicting intraocular lens power. DESIGN: Retrospective, consecutive case series. PARTICIPANTS: Eyes undergoing cataract extraction with at least 1 month of follow-up after surgery at an ambulatory surgical centre in Toronto. METHODS: Consecutive sample of 228 cataract extractions with monofocal, trifocal, or toric intraocular lens implantation from November 1, 2017, to December 31, 2019. The spherical equivalent was predicted preoperatively with Barrett Universal II, Hill-Radial Basis Function (RBF), SRK/T, Holladay I, Holladay II, Haigis, and HofferQ using biometry measurements and intraoperatively with wavefront aberrometry. The primary outcomes were mean prediction error and proportion of eyes with a spherical equivalent within 0.5 D of the refractive target at postoperative month 1. RESULTS: The analysis included 159 eyes with 52% females and a mean age of 69.4 years. Formulae with the lowest mean prediction error were Hill-RBF (0.32 D ± 0.02 D), Barrett Universal II (0.32 D ± 0.02 D), intraoperative aberrometry (0.32 D ± 0.02 D), SRK/T (0.33 D ± 0.02 D), Holladay II (0.34 D ± 0.03 D), Holladay I (0.35 D ± 0.02 D), Haigis (0.37 D ± 0.02 D), and HofferQ (0.42 D ± 0.02 D). There were no statistically significant differences between intraoperative aberrometry and the preoperative formulae. Formulae with the highest proportion of eyes within 0.5 D of the refractive target were intraoperative aberrometry (82%), Barrett Universal II (81%), Hill-RBF (80%), SRK/T (77%), Holladay II (76%), Holladay I (75%), Haigis (71%), and HofferQ (70%). CONCLUSIONS: Intraoperative aberrometry and modern preoperative biometry formulae are equally effective at reaching the refractive target. In normal eyes, intraoperative aberrometry does not appear to provide any additional benefit to modern prediction formulae.

Cardiac manifestations of IgG4-related disease: a case series.

Background: IgG4-related disease (IgG4-RD) is an autoimmune condition affecting almost every organ system, with an early inflammatory phase and later fibrotic consequences. Vascular manifestations, particularly, large-vessel involvement in IgG4-RD, are well described. However, important IgG4-related effects on medium-sized arteries and the pericardium are less well recognized. These less frequently reported cardiovascular effects of IgG4-RD include coronary artery stenosis, pericardial disease, cardiac masses, and valvular heart disease. Case summary: This case series focuses on three patients that demonstrate the cardiovascular effects of IgG4-RD and the pitfalls and importance of early diagnosis. Cases 1 and 2 presented with cardiac manifestations prior to more typical organ systems being affected which led to a delay in diagnosis. Case 1 presented with an acute myocardial infarction secondary to IgG4-RD of the coronary arteries and Case 2 presented with pericarditis which progressed to pericardial constriction due to IgG4-RD. Case 3 already had a diagnosis of IgG4-RD from a prior renal biopsy which raised the index of suspicion that his pericardial disease and thoracic mass were also related to IgG4-RD. Discussion: Cardiac manifestations of IgG4-RD remain under-recognized and include coronary artery and pericardial disease. These manifestations often precede more typical manifestations in other organ systems. Recognizing cardiac manifestations of IgG4-RD on cardiac imaging can raise clinical suspicion and act as a catalyst to ascertain a confirmatory diagnosis. Early diagnosis and treatment are crucial to prevent potentially fatal outcomes and irreversible fibrosis.

Evaluation of Protective Properties of Commercially Available Medical Helmets: Are Medical Helmets Protective?

OBJECTIVES: The aims of the study were to evaluate and to compare protective properties of commercially available medical helmets for a set of standardized head injury risk measures. METHODS: Eleven helmet types were evaluated to represent the variety of commercially available medical helmet designs and manufacturers. A test mannequin and sensor apparatus were used to simulate a backward-standing fall. The head/neck size, mass, and "standing" height of the mannequin (5'9″) were representative of a 50th percentile male. A triaxial array was placed at the head center of mass to position 3 linear accelerometers and 3 angular rate sensors. Data were collected for 5 single trials for each helmet, as well as 5 repeated trials. Five trials were also collected with no helmet scenarios. Three head injury risk measures were examined (linear acceleration, angular acceleration, and head injury criterion). Data were analyzed by clinical cutoff thresholds and continuous values. RESULTS: Helmets varied in their performance across head injury risk measures. All helmets provided higher levels of protection compared with no helmet scenarios. No helmets were protective for subdural hematoma (measured by angular acceleration). All helmets lost protective properties with repeated falls. Results for skull fracture risk were inconsistent between linear acceleration and head injury criterion injury risk measures. CONCLUSIONS: No helmets were protective across all head injury risk measures. Medical helmets may reduce some fall injury severity but may not prevent all types of head injury. All helmets exhibited worsening of protective properties with repeated falls. We recommend medical helmets be replaced after each fall incident where the helmet impacts another surface.

Symptomology following mRNA vaccination against SARS-CoV-2.

Despite demonstrated efficacy of vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease-2019 (COVID-19), widespread hesitancy to vaccination persists. Improved knowledge regarding frequency, severity, and duration of vaccine-associated symptoms may help reduce hesitancy. In this prospective observational study, we studied 1032 healthcare workers who received both doses of the Pfizer-BioNTech SARS-CoV-2 mRNA vaccine and completed post-vaccine symptom surveys both after dose 1 and after dose 2. We defined appreciable post-vaccine symptoms as those of at least moderate severity and lasting at least 2 days. We found that symptoms were more frequent following the second vaccine dose than the first (74% vs. 60%, P < 0.001), with >80% of all symptoms resolving within 2 days. The most common symptom was injection site pain, followed by fatigue and malaise. Overall, 20% of participants experienced appreciable symptoms after dose 1 and 30% after dose 2. In multivariable analyses, female sex was associated with greater odds of appreciable symptoms after both dose 1 (OR, 95% CI 1.73, 1.19-2.51) and dose 2 (1.76, 1.28-2.42). Prior COVID-19 was also associated with appreciable symptoms following dose 1, while younger age and history of hypertension were associated with appreciable symptoms after dose 2. We conclude that most post-vaccine symptoms are reportedly mild and last <2 days. Appreciable post-vaccine symptoms are associated with female sex, prior COVID-19, younger age, and hypertension. This information can aid clinicians in advising patients on the safety and expected symptomatology associated with vaccination.

A comparative analysis of 12 intraocular lens power formulas.

PURPOSE: To evaluate the accuracy of 12 intraocular lens (IOL) power calculations: Barrett Universal II, EVO, Haigis, Hill-RBF version 2.0, Hoffer Q, Holladay 1, Holladay 2, Kane, Olsen, SRK/T, Super Formula and T2. METHODS: In this retrospective consecutive case series, cataract extraction and IOL implantation cases in Toronto, Canada, were recruited between 2017 and 2019. Refractive predictions were compared to the observed 1-month postoperative spherical equivalent to determine the refractive error for each formula cohort. Subgroup analysis stratified eyes into short (≤ 22.5 mm)-, intermediate (22.5 mm-25.5 mm)- and long (≥ 25.5 mm)-axial length (AL) cohorts. The primary outcome was the percentage of cases within ± 0.50D of refractive error. RESULTS: Overall, 764 cataract cases were analyzed. Formulas with the highest percentage of eyes within ± 0.50D of refractive error, in decreasing order, were: Kane (77.7%), Barrett Universal II (77.4%), EVO (76.6%), T2 (76.4%), Super (75.9%), Holladay 1 (75.4%), Hill-RBF 2.0 (74.7%), SRK/T (72.6%), Hoffer Q (72.5%), Haigis (71.7%), Olsen (67.4%) and Holladay 2 (67.3%). For short-AL eyes, the Holladay 1 formula was most accurate (n = 69, 78.3% within ± 0.50D), and for long-AL eyes, the Barrett Universal II formula was most accurate (n = 116, 76.7% within ± 0.50D). Kane, Barrett, EVO, T2 and Super formulas led to a significantly lower mean absolute error compared to the open-source calculations with optimized lens constants (p-value: < 0.001-0.042). CONCLUSIONS: The Kane formula was the most accurate formula for the overall analysis. The Holladay 1 calculation was most accurate for short-AL cases, whereas the Barrett Universal II was superior for long-AL eyes.

Plant-based diets, pescatarian diets and COVID-19 severity: a population-based case-control study in six countries.

BACKGROUND: Several studies have hypothesised that dietary habits may play an important role in COVID-19 infection, severity of symptoms, and duration of illness. However, no previous studies have investigated the association between dietary patterns and COVID-19. METHODS: Healthcare workers (HCWs) from six countries (France, Germany, Italy, Spain, UK, USA) with substantial exposure to COVID-19 patients completed a web-based survey from 17 July to 25 September 2020. Participants provided information on demographic characteristics, dietary information, and COVID-19 outcomes. We used multivariable logistic regression models to evaluate the association between self-reported diets and COVID-19 infection, severity, and duration. RESULTS: There were 568 COVID-19 cases and 2316 controls. Among the 568 cases, 138 individuals had moderate-to-severe COVID-19 severity whereas 430 individuals had very mild to mild COVID-19 severity. After adjusting for important confounders, participants who reported following 'plant-based diets' and 'plant-based diets or pescatarian diets' had 73% (OR 0.27, 95% CI 0.10 to 0.81) and 59% (OR 0.41, 95% CI 0.17 to 0.99) lower odds of moderate-to-severe COVID-19 severity, respectively, compared with participants who did not follow these diets. Compared with participants who reported following 'plant-based diets', those who reported following 'low carbohydrate, high protein diets' had greater odds of moderate-to-severe COVID-19 (OR 3.86, 95% CI 1.13 to 13.24). No association was observed between self-reported diets and COVID-19 infection or duration. CONCLUSION: In six countries, plant-based diets or pescatarian diets were associated with lower odds of moderate-to-severe COVID-19. These dietary patterns may be considered for protection against severe COVID-19.