Optical clocks at sea.

Deployed optical clocks will improve positioning for navigational autonomy1, provide remote time standards for geophysical monitoring2 and distributed coherent sensing3, allow time synchronization of remote quantum networks4,5 and provide operational redundancy for national time standards. Although laboratory optical clocks now reach fractional inaccuracies below 10-18 (refs. 6,7), transportable versions of these high-performing clocks8,9 have limited utility because of their size, environmental sensitivity and cost10. Here we report the development of optical clocks with the requisite combination of size, performance and environmental insensitivity for operation on mobile platforms. The 35 l clock combines a molecular iodine spectrometer, fibre frequency comb and control electronics. Three of these clocks operated continuously aboard a naval ship in the Pacific Ocean for 20 days while accruing timing errors below 300 ps per day. The clocks have comparable performance to active hydrogen masers in one-tenth the volume. Operating high-performance clocks at sea has been historically challenging and continues to be critical for navigation. This demonstration marks a significant technological advancement that heralds the arrival of future optical timekeeping networks.

Xerostomia in 75-85-year-olds: A longitudinal population study.

BACKGROUND: Xerostomia can pose significant problems for many elderly people. OBJECTIVES: To investigate longitudinal changes in prevalence, persistence, progression, remission and incidence of xerostomia from age 75 to 85 years. METHODS: All 75-year-olds (born 1932) from two Swedish counties, Sweden were mailed a questionnaire in 2007 (N = 5195), and again in 2017 when they were aged 85 (N = 3323). The total response rates at ages 75 and 85 years were 71.9% and 60.8%, respectively. A 'panel', those who participated in both surveys, comprised 1701 individuals (response rate 51.2%). RESULTS: At age 85, there was almost a doubling of self-reported 'yes often' xerostomia compared with age 75 (from 6.2% to 11.3%) and was almost twice as common in women than men (p < .001). When combining 'yes often'/'yes sometimes', xerostomia increased from 33.4% to 49.0%, and was more so among women (p < .001). Xerostomia was commoner at night than daytime, with 23.4% reporting 'yes often' night-time xerostomia at 85 compared with 18.5% at 75, and was also higher in women (p < .001). Progression rates for daytime and night-time xerostomia were 34.2% and 38.1%, for persistence 67.4% and 68.6%, and for remission 24.4% and 16.5%. Average yearly incidence was higher in women than men for both daytime (3.6% vs. 3.2%) and night-time (3.9% vs. 3.7%). Regression analyses predicted protective factors for developing xerostomia reported at age 75 as good general and oral health, absence of medications/intraoral symptom/s, good chewing function and social interaction. CONCLUSIONS: Xerostomia increases markedly from age 75 to 85 years.

Topological data analysis in medical imaging: current state of the art.

Machine learning, and especially deep learning, is rapidly gaining acceptance and clinical usage in a wide range of image analysis applications and is regarded as providing high performance in detecting anatomical structures and identification and classification of patterns of disease in medical images. However, there are many roadblocks to the widespread implementation of machine learning in clinical image analysis, including differences in data capture leading to different measurements, high dimensionality of imaging and other medical data, and the black-box nature of machine learning, with a lack of insight into relevant features. Techniques such as radiomics have been used in traditional machine learning approaches to model the mathematical relationships between adjacent pixels in an image and provide an explainable framework for clinicians and researchers. Newer paradigms, such as topological data analysis (TDA), have recently been adopted to design and develop innovative image analysis schemes that go beyond the abilities of pixel-to-pixel comparisons. TDA can automatically construct filtrations of topological shapes of image texture through a technique known as persistent homology (PH); these features can then be fed into machine learning models that provide explainable outputs and can distinguish different image classes in a computationally more efficient way, when compared to other currently used methods. The aim of this review is to introduce PH and its variants and to review TDA's recent successes in medical imaging studies.

Temporal changes and gender differences related to orofacial symptoms in two cohorts of 75-year-old Swedish subjects examined in 2007 and 2017: A repeated cross-sectional study.

OBJECTIVES: To compare two cohorts of 75-year-old persons, born 10 years apart, in regard to reported symptoms related to temporomandibular disorders (TMD) and orofacial complaints with special reference to gender differences. MATERIAL AND METHODS: In 2007, a questionnaire comprising questions on social factors, general and oral health, and a series of attitude-related questions was mailed to all individuals born in 1932 living in two Swedish counties (N = 5195), and in 2017 to all born in 1942 (N = 7204). The response rate for the cohort examined in 2007 was 71.9% (n = 3735) and 70.7% (n = 5091) for the cohort examined in 2017. Bivariate statistical analyses were applied. RESULTS: Reported bruxism and pain from the temporomandibular joint were significantly higher in the 1942 cohort compared to the 1932 cohort, while reports of oral lesions and daytime dry mouth were lower. Women reported problems significantly more frequently in most of the domains investigated in both 2007 and 2017, that is, TMD, burning mouth, sensitive teeth, oral lesions, taste changes, daytime/night-time dry mouth, except bad breath. CONCLUSIONS: TMD-related symptoms increased while complaints from oral lesions and daytime mouth dryness decreased between 2007 and 2017. Temporal changes were otherwise few, but the findings underline the gender inequalities that exist, to the disadvantage of women. This must be considered when planning for clinical care/dental education to appropriately address the needs of older people.

Comparative study of left atrium epicardial fat tissue pattern using persistent homology approach.

OBJECTIVE: Atrial Fibrillation (A-fib) is an abnormal heartbeat condition in which the heart races and beats in an uncontrollable way. It is observed that the presence of increased epicardial fat/fatty tissue in the atrium can lead to A-fib. Persistent homology using topological features can be used to recapitulate enormous amounts of spatially complicated medical data into a visual code to identify a specific pattern of epicardial fat tissue with non-fat tissue. Our aim is to evaluate the topological pattern of left atrium epicardial fat tissue with non-fat tissue. RESULTS: A topological data analysis approach was acquired to study the imaging pattern between the left atrium epicardial fat tissue and non-fat tissue patches. The patches of eight patients from CT images of the left atrium heart were used and categorized into "left atrium epicardial fat tissue" and "non-fat tissue" groups. The features that distinguish the "epicardial fat tissue" and "non-fat tissue" groups are extracted using persistent homology (PH). Our result reveals that our proposed research can discriminate between left atrium epicardial fat tissue and non-fat tissue. Specifically, the range of Betti numbers in the epicardial tissue is smaller (0-30) than the non-fat tissue (0-100), indicating that non-fat tissue has good topology.

Shedding of infectious SARS-CoV-2 despite vaccination.

The SARS-CoV-2 Delta Variant of Concern is highly transmissible and contains mutations that confer partial immune escape. The emergence of Delta in North America caused the first surge in COVID-19 cases after SARS-CoV-2 vaccines became widely available. To determine whether individuals infected despite vaccination might be capable of transmitting SARS-CoV-2, we compared RT-PCR cycle threshold (Ct) data from 20,431 test-positive anterior nasal swab specimens from fully vaccinated (n = 9,347) or unvaccinated (n = 11,084) individuals tested at a single commercial laboratory during the interval 28 June- 1 December 2021 when Delta variants were predominant. We observed no significant effect of vaccine status alone on Ct value, nor when controlling for vaccine product or sex. Testing a subset of low-Ct (<25) samples, we detected infectious virus at similar rates, and at similar titers, in specimens from vaccinated and unvaccinated individuals. These data indicate that vaccinated individuals infected with Delta variants are capable of shedding infectious SARS-CoV-2 and could play a role in spreading COVID-19.

Satisfaction with dental appearance in two cohorts of 75-year-olds examined in 2007 and 2017: A repeated cross-sectional study.

BACKGROUND: Satisfaction with dental appearance plays an important role in the self-esteem and psychological well-being of the elderly, the significance of which the attending dentist may not always be fully cognisant of. OBJECTIVES: To assess the level of satisfaction with dental appearance, its associated factors and temporal changes in two cohorts of 75-year-old Swedes born 10 years apart. METHODS: In 2007, a questionnaire was mailed to all those living in Örebro and Östergötland counties, Sweden, who were born in 1932 (n = 5195), and in 2017 to all born in 1942 (n = 7204). The evaluation was carried out with a global question 'Are you satisfied with the appearance of your teeth?', and four attitude-related statements about dental appearance. RESULTS: About 80% in both cohorts were 'very satisfied' or 'to large extent satisfied' with their dental appearance. The 1932 cohort was significantly more concerned about their dental appearance than the 1942 cohort, and women were generally also significantly more concerned than men. In the regression analysis, 'very satisfied' with dental appearance was predicted by good chewing efficiency, having complete dentures, no impact from Oral Impacts on Daily Performance, disagreement that 'minor esthetic imperfections of the teeth have no importance, only they should function well', better perceived general health than same-aged peers and belonging to the 1932 cohort. CONCLUSION: Satisfaction with dental appearance among 75-year-olds was generally high, with attitudes varying by gender and temporally. Women and the earlier-born generation (1932) were more concerned about dental appearance than men and the later-born generation (1942), respectively.

Prediction of xerostomia in a 75-year-old population: A 25-year longitudinal study.

OBJECTIVES: To follow the same individuals from age 50 up to 75 years to report on prevalence, persistence, progression, remission, incidence and predictors for xerostomia. METHODS: A questionnaire was distributed to all 50-years-olds (1992) in two Swedish counties (N = 8888) and repeated at the age of 65 (2007) and 75 years (2017). 3060 individuals responded on all three occasions (response rate 42.5%). Xerostomia was assessed with two questions. Additional questions addressed inter alia general/oral health and oral function. RESULTS: Reported prevalence of daytime xerostomia were 23.3% and 14.7%, and 39.5% and 27.5% in women and men, age 50 and 75, respectively. Night-time prevalence was higher. At age 50, 27.4% women and 24.0% men reported having dry mouth, and at age 75, 61.0% and 53.8%, respectively. At all time points, women reported significantly more xerostomia than men. Progression (deterioration) was common, and persistence (continuing presence) was high, while 25-year incidence for daytime xerostomia was 16.2% and 12.8%, and 33.6% and 29.8% at night-time, for women and men, respectively. Based on reports at age 50, regression analyses showed that prediction for developing xerostomia during the observation period, and reporting xerostomia at age 75 years, were female gender, impaired general health, chewing, jaw opening and intraoral problems, dissatisfaction with dental appearance, low education and having white/plastic filling. CONCLUSIONS: Xerostomia is common in older people, especially at night and in women. It can be predicted by diverse factors reported earlier in life. CLINICAL SIGNIFICANCE: Clinicians need to be made aware of that elderly often suffers from dry mouth so that they can recommend effective measures to eliminate or ease the patients accompanying symptoms and also exclude or lessen possible negative impact on oral health related to xerostomia.

Seasonal variations in physical activity among Norwegian elementary school children in Arctic regions.

The aim of this study was to measure seasonal variations in physical activity (PA) during Polar Nights (PN) and Polar Days (PD) among elementary school children in the Arctic regions of Norway. One hundred and seventy-eight schoolchildren from 1st, 3rd, 5thand 7th grade participated in the study. Physical activity was measured for seven consecutive days with an ActiGraph GT3X-BT accelerometer and is expressed as total PA incounts per minute (cpm) and moderate-to-vigorous activity (MVPA) (min∙day-1). During PN, 51% of boys and 33% of girls met the PA recommendations, whereas 36% of boys and 34% of girls met the recommendations during PD. Time spent doing MVPA did not differ between the two seasons (all p ≥ 0.073). Overall, the children accumulated 613 ±154 cpm during PN, which was lower than during PD 704 ± 269 cpm, p < 0.001). A larger proportion of boys than girls met the PA recommendations during PN compared with PD. Our findings did not show any clear seasonal variation for MVPA or total PA among children,except for some differences within sexes in different grades. This study indicates that interventions aimed at increasing PA should be implemented throughout the year in the Arctic regions. .

Vaccinated and unvaccinated individuals have similar viral loads in communities with a high prevalence of the SARS-CoV-2 delta variant

The SARS-CoV-2 Delta Variant of Concern is highly transmissible and contains mutations that confer partial immune escape. The emergence of Delta in North America caused the first surge in COVID-19 cases after SARS-CoV-2 vaccines became widely available. To determine whether individuals infected despite vaccination might be capable of transmitting SARS-CoV-2, we compared RT-PCR cycle threshold (Ct) data from 20,431 test-positive anterior nasal swab specimens from fully vaccinated (n = 9,347) or unvaccinated (n=11,084) individuals tested at a single commercial laboratory during the interval 28 June - 1 December 2021 when Delta variants were predominant. We observed no significant effect of vaccine status alone on Ct value, nor when controlling for vaccine product or sex. Testing a subset of low-Ct (<25) samples, we detected infectious virus at similar rates, and at similar titers, in specimens from vaccinated and unvaccinated individuals. These data indicate that vaccinated individuals infected with Delta variants are capable of shedding infectious SARS-CoV-2 and could play a role in spreading COVID-19.

Changes in conditions related to reported oral and general health over a ten-year period as reflected in two cohorts of 75-year-old subjects examined in 2007 and 2017.

BACKGROUND: The rapidly ageing and increasingly dentate population puts great demands on society regarding the provision of adequate medical and dental care facilities. OBJECTIVES: To present changes in reported demographic, general and oral health factors in two cohorts of 75 year olds in 2007 and 2017, and to analyse factors associated with self-reported number of remaining teeth and chewing efficiency. MATERIAL AND METHODS: All 75-year-old people living in two Swedish counties received a questionnaire in 2007 and in 2017. The response rates in 2007 and in 2017 were 71.9% (n = 3735) and 70.7% (n = 5091), respectively. Reported number of teeth was clinically validated in a selected subgroup. RESULTS: The 2017 cohort reported significantly better general health and dental state. Edentulousness was 7.8% in 2007 and 2.3% in 2017, while 'very good' chewing efficiency was 55.2% and 60.5%, respectively. Born outside Sweden, single living, not feeling healthy and smoking predicted reduced number of teeth in both cohorts. Impaired chewing efficiency in both cohorts was predicted by being born outside Sweden, lower education, not feeling healthy, reduced number of teeth and denture wearing. CONCLUSIONS: Seventy-five-year-old people in Sweden reported much better oral and general health in 2017 compared to 2007. In 2017, 75% had practically all natural teeth present and only 2% were edentulous. This development of an increasingly dentate and partially dentate ageing population will put high demands on the oral healthcare system and will need adapting undergraduate/postgraduate education and management strategies to meet the requirements of the elderly.

Self-reported dry mouth in 50- to 80-year-old Swedes: Longitudinal and cross-sectional population studies.

Xerostomia is a common condition among elderly. The objectives were to examine prevalence, persistence, progression, yearly incidence of xerostomia, associated background factors and its influence on oral impacts on daily performances (OIDP) in 50- to 80-year-old people. In 1992, a questionnaire was sent to all 50-year-old (n = 8888) and in 2007 to all 75-year-old persons (n = 5195) living in two Swedish counties. In 2012, the same questionnaire was sent to both age cohorts, now 70- and 80-year-old. Response rate was for the 50-, 70- 75- and 80-year-old groups 71.4%, 72.2%, 71.9% and 66.4%, respectively. In the 50- to 70-year-old sample, 40.3% of the participants answered all five examinations and in the 75-80 group 49.5% (intact samples). In all age groups, xerostomia was significantly more prevalent in women than in men. At age 80, "often mouth dryness at night" was reported by 24.3% and 16.2% of women and men, respectively. Prevalence increased with age and was more frequent at night-time. Persistence of xerostomia was reported by 61.4%-77.5%, progression by 11.5%-33.0% and remission by 5.7%-11.3%. Average yearly incidence was 0.99%-3.28%. Xerostomia was more prevalent in those who reported a negative impact on OIDP. Highest odd ratios for xerostomia were burning mouth (OR 12.0), not feeling healthy (OR 5.1) and medicine usage (OR 3.9). Xerostomia is common in older age, persistence is high and progression common. The comorbidity between xerostomia, oral health problems and impaired general health needs to be taken into consideration when providing dental care to elderly patients.

A 3-year study of patients with tinnitus and jaw muscle tenderness.

Objective: This study evaluated three-year results of treatment with an interocclusal appliance in 89 tinnitus patients with jaw muscle tenderness. Methods: Subjective tinnitus severity was recorded using a visual analog scale (VAS). The number of tender muscles was registered. The patients were followed annually. After three years, 64 patients were examined (72%). Results: Tinnitus severity at baseline was high (mean VAS value 68.3). After one year, the VAS values were substantially lower (mean 37.4; p < 0.001). During the following two years, there were no significant changes in VAS values. The mean number of tender muscles decreased from seven to two after one year and remained at this number for up to three years. Conclusion: In many tinnitus patients with signs of temporomandibular disorders (TMDs), intraoral splint therapy reduced tinnitus severity and jaw muscle symptoms. The favorable results after one year remained for up to three years without significant changes.

An International Survey among Prosthodontists of the Use of Mandibular Implant-Supported Dental Prostheses.

PURPOSE: To evaluate the use of implant-supported overdentures (IOD) and implant-supported fixed dental prostheses (IFDP) in patients with edentulous mandibles among international prosthodontists. MATERIALS AND METHODS: A questionnaire was sent by e-mail to all clinically active prosthodontists in the International College of Prosthodontists with questions related to implant treatment of the edentulous mandible performed in 2015. RESULTS: One hundred and sixteen prosthodontists from 33 countries responded to the questionnaire. The vast majority of the responding prosthodontists was faculty or worked in private practice, and the great majority had performed treatment with mandibular implant-supported dental prostheses; however, two thirds of the respondents reported that <20% of the implant patients in their clinic had received treatment related to edentulous mandibles. The majority reported using 2 implants (84%), while 13% used 4 for overdenture retention. There were great variations regarding retention systems used for mandibular IODs; the most common was individual Locator attachments. Cost was considered the most common reason to choose mandibular IOD, There was a wide variation of materials used for mandibular IFDPs. The most common combination included milled titanium frameworks and acrylic resin teeth. CONCLUSIONS: This survey, completed by 116 prosthodontists from 33 countries, showed that implant treatment for edentulous mandibles is common, but there was great variation among the respondents regarding amount of treatments performed, design, and materials used for the implant prostheses.

The pacing strategy and technique of male cross-country skiers with different levels of performance during a 15-km classical race.

In this study the pacing strategy, cycle characteristics and choice of technique of elite male cross-country (XC) skiers during a three-lap, 15-km classical race with interval start were measured. During the Norwegian Championships in 2016, fast (n = 18, age: 26±4 yr; height: 182±4 cm; body mass: 78±3 kg (means±SD)) and slow skiers (n = 18, age: 22±2 yr; height: 183±5 cm; body mass: 78±6 kg) were video recorded on flat (0°), intermediate (3.5°) and uphill sections (7.1°) of the first and final laps. All skiers adopted a positive pacing strategy, skiing more slowly (11.8%) with shorter cycles (11.7%) on the final than first lap (both p<0.001; pη2 = 0.93 and 0.87, respectively). The fast skiers were 7.0% faster overall (p<0.001, d = 4.20), and 6.1% (p<0.001, d = 3.32) and 7.0% (p<0.001, d = 3.68) faster on the first and final laps, respectively, compared to slower skiers. On all sections of both laps, the fast skiers exhibited 9.5% more rapid (pη2 = 0.74) and 8.9% (pη2 = 0.48) longer cycles (both p<0.001). On intermediate terrain, the fast skiers employed primarily double poling (DP, 38.9% on the first lap) and double poling with a kick (DPKICK, 50% on the final lap). In contrast, the slow skiers utilized for the most part DP alone (lap 1: 33.3%, lap 3: 38.9%) or in combination with other techniques (lap 1: 33.3%, lap 3: 38.9%) and decreased their usage of DPKICK from 27.8% on the first to 16.7% on the final lap. Skiing velocity on flat and intermediate terrain proved to be the best predictor of race performance (p<0.001). In conclusion, during a 15-km classical XC skiing race, velocity and cycle length decreased from the first to the final lap, most extensively on flat terrain and least uphill. Moreover, on the intermediate sections the fast and slow skiers chose to use different techniques.

Uncovering precision phenotype-biomarker associations in traumatic brain injury using topological data analysis.

BACKGROUND: Traumatic brain injury (TBI) is a complex disorder that is traditionally stratified based on clinical signs and symptoms. Recent imaging and molecular biomarker innovations provide unprecedented opportunities for improved TBI precision medicine, incorporating patho-anatomical and molecular mechanisms. Complete integration of these diverse data for TBI diagnosis and patient stratification remains an unmet challenge. METHODS AND FINDINGS: The Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot multicenter study enrolled 586 acute TBI patients and collected diverse common data elements (TBI-CDEs) across the study population, including imaging, genetics, and clinical outcomes. We then applied topology-based data-driven discovery to identify natural subgroups of patients, based on the TBI-CDEs collected. Our hypothesis was two-fold: 1) A machine learning tool known as topological data analysis (TDA) would reveal data-driven patterns in patient outcomes to identify candidate biomarkers of recovery, and 2) TDA-identified biomarkers would significantly predict patient outcome recovery after TBI using more traditional methods of univariate statistical tests. TDA algorithms organized and mapped the data of TBI patients in multidimensional space, identifying a subset of mild TBI patients with a specific multivariate phenotype associated with unfavorable outcome at 3 and 6 months after injury. Further analyses revealed that this patient subset had high rates of post-traumatic stress disorder (PTSD), and enrichment in several distinct genetic polymorphisms associated with cellular responses to stress and DNA damage (PARP1), and in striatal dopamine processing (ANKK1, COMT, DRD2). CONCLUSIONS: TDA identified a unique diagnostic subgroup of patients with unfavorable outcome after mild TBI that were significantly predicted by the presence of specific genetic polymorphisms. Machine learning methods such as TDA may provide a robust method for patient stratification and treatment planning targeting identified biomarkers in future clinical trials in TBI patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01565551.

Zirconia abutments for single-tooth implant restorations: a 10- to 11-year follow-up study.

OBJECTIVES: To evaluate the clinical outcome of custom-made zirconia abutments for implant-supported single-tooth restorations 10-11 years after insertion. MATERIAL AND METHODS: The study comprises a clinical examination of 23 patients with 30 restorations placed 10-11 years ago. Oral surgeons placed the implants. The prosthodontic treatment was provided at a prosthodontic specialist clinic. The restoration was either an all-ceramic crown for cementation or a screw-retained one-piece restoration with the veneering porcelain baked directly to the zirconia abutment. Besides the clinical and radiographic examination at the 10- to 11-year follow-up, the patients' records were scrutinized regarding clinical and radiographic data from insertion of the restoration up to the last visit at the clinic. RESULTS: The zirconia abutments performed well. Both technical and biological complications were rare; most patients were in general extremely satisfied with the restorations. No all-ceramic crowns fractured during the observation period. One implant was lost after 5½ years in service. There were no significant differences for changes in any of the soft tissue registrations or the peri-implant marginal bone level between the conventional two-piece abutment-crown restoration and the one-piece restoration. The peri-implant bone level changes from placement to the clinical examination 10-11 years later were small (mean 0.26 mm, SD 0.6 mm). CONCLUSIONS: Zirconia abutments for single-implant crowns demonstrated excellent technical and biological results over 10-11 years of function, and most patients were extremely satisfied with the aesthetics and the function of their single-implant restorations.

Experiences among children and adolescents of living with spina bifida and their visions of the future.

Purpose Transitioning to independence may be problematic for persons with spina bifida (SB). Experiences of young persons with SB may provide insights into this group's needs for support. Therefore, the aim of this study was to investigate children's and adolescents' experiences of living with SB, their social and emotional adjustment, and their thoughts about becoming independent adults. Method Semi-structured interviews were conducted with young persons with SB (N = 8, age range 10-17 years). Social and emotional problems were assessed using Beck Youth Inventories. The interview transcripts were analyzed using qualitative content analysis. Results Three main themes were found: being a person with SB; everyday living as a person with SB; and preparing for life as an adult with SB. Indications of emotional and social problems were most prominent among participants with milder physical disability. Conclusions The findings indicate that young persons with SB may overestimate their independence. Other potentially problematic areas were lack of motivation, planning and preparedness for becoming independent. Research on transition to independence in this group should consider assistance at an early age in planning and executing strategies for independence. In addition, the potentially difficult situation for young persons with mild SB should be investigated further. Implications for rehabilitation Children and adolescents with spina bifida might lack the motivation and skills for planning their future and health care programmes should therefore include preparations for life as an adult. Clinical assessment of the level of independence should specifically distinguish between the activities they know how to do and what tasks they actually execute independently. Routine follow-ups should include screening for problems with social and emotional adjustment. Be aware of a potential condition-severity paradox whereby those with less severe impairment might have an increased risk of developing symptoms of social and emotional problems.

Some issues related to evidence-based implantology.

This article reviews relevant dental literature to answer some frequent questions related to evidence-based implantology. There are hundreds of implant systems on the market, but the majority lack clinical documentation. Recommended number of implants for full-arch fixed prostheses is four or five in the mandible but at least six in the maxilla. Less expensive implant-retained overdentures make implant treatment available to a greater portion of edentulous subjects. Mandibular overdentures on two implants, and even one implant, have shown excellent long-term outcomes. In the maxilla, less than four implants are not recommended for good results. Single implant restorations have good prognosis, but placement of the implant should be postponed until adulthood. Osseointegrated implants have revolutionized clinical dentistry. However, in a global perspective, implants make up only a small part of all prosthodontic treatment. Knowledge and skill in conventional prosthodontics must be maintained as it will remain the most common part of the specialty.

Topological data analysis for discovery in preclinical spinal cord injury and traumatic brain injury.

Data-driven discovery in complex neurological disorders has potential to extract meaningful syndromic knowledge from large, heterogeneous data sets to enhance potential for precision medicine. Here we describe the application of topological data analysis (TDA) for data-driven discovery in preclinical traumatic brain injury (TBI) and spinal cord injury (SCI) data sets mined from the Visualized Syndromic Information and Outcomes for Neurotrauma-SCI (VISION-SCI) repository. Through direct visualization of inter-related histopathological, functional and health outcomes, TDA detected novel patterns across the syndromic network, uncovering interactions between SCI and co-occurring TBI, as well as detrimental drug effects in unpublished multicentre preclinical drug trial data in SCI. TDA also revealed that perioperative hypertension predicted long-term recovery better than any tested drug after thoracic SCI in rats. TDA-based data-driven discovery has great potential application for decision-support for basic research and clinical problems such as outcome assessment, neurocritical care, treatment planning and rapid, precision-diagnosis.