Data-driven modelling with coarse-grid network models

We propose to use a conventional simulator, formulated on the topology of a coarse volumetric 3D grid, as a data-driven network model that seeks to reproduce observed and predict future well responses. The conceptual difference from standard history matching is that the tunable network parameters are calibrated freely without regard to the physical interpretation of their calibrated values. The simplest version uses a minimal rectilinear mesh covering the assumed map outline and base/top surface of the reservoir. The resulting CGNet models fit immediately in any standard simulator and are very fast to evaluate because of the low cell count. We show that surprisingly accurate network models can be developed using grids with a few tens or hundreds of cells. Compared with similar interwell network models (e.g., Ren et al., 2019, 10.2118/193855-MS), a typical CGNet model has fewer computational cells but a richer connection graph and more tunable parameters. In our experience, CGNet models therefore calibrate better and are simpler to set up to reflect known fluid contacts, etc. For cases with poor vertical connection or internal fluid contacts, it is advantageous if the model has several horizontal layers in the network topology. We also show that starting with a good ballpark estimate of the reservoir volume is a precursor to a good calibration.publishedVersio

Radiographic markers of hip dysplasia in young adults: predictive effect of factors in early life

Background and objectives Acetabular dysplasia in young adults occurs, despite screening for developmental hip dysplasia (DDH) in the neonatal period. We aimed to examine how early life factors predict radiographic measurements of acetabular dysplasia at 18–19 years of age. Methods From a previous randomized trial (n=12,014; 1988–90) evaluating the role of hip ultrasound in newborn screening of DDH, 4469 participants (2193 males) were invited to a follow-up 18 years later (2007–09), of which 2370 (53% attendance; 932 males) met. We examined associations between early life factors and four radiographic measurements for acetabular dysplasia at skeletal maturity. Hierarchical regressions, with addition of variables observed/ measured consecutively in time, were analyzed using mixed efects models considering hip as the unit in the analyses. The study is approved by the Regional Ethics Committee. Results In total, 2340 participants (921 boys), mean age 18.7 years, (SD 0.6) had hip radiographs performed at followup and were included. Early life factors signifcantly predicting radiographic acetabular dysplasia at age 18–19-years included female gender, breech, low acetabular inclination (alpha) angle and sonographic instability, abduction treatment, as well as the velocity of growth during childhood. A positive family history of DDH was not associated with acetabular dysplasia at skeletal maturity. Conclusion The acetabular inclination (alpha) angle as measured on ultrasound at birth turned out to be a signifcant predictor of dysplasia at 18–19 years of age. The discordant role of a positive family history in early versus adult hip dysplasia is intriguing, warranting further studies on the genetic mechanisms of DDH

Influences of behaviour and attitude on education related inequality in tooth loss: findings from Norway and Sweden over 5 years of follow-up

Objectives Following community dwelling cohorts in Norway and Sweden from 65 to 70 years, this study aimed to answer the following questions; Is there cross country variation in educational inequality in tooth loss between the Norwegian and Swedish cohorts? Does oral health behaviours and attitudinal beliefs play a role in explaining educational inequality in tooth loss across time and cohorts? Material and Methods In 2007 and 2012 Statistics Norway administered mailed questionnaires to all individuals born in 1942 in three counties. The response rate was 58% (n = 4211) in 2007 and 54.5% (n = 3733) in 2012. In Sweden the same questionnaires were sent to the 1942 cohort in two counties. The final response rate in 2007 and 2012 were respectively, 73.1% (n = 6078) and 72.2% (n = 5697). Results In Norway, tooth loss prevalence was 21.8% in 2007 and 23.2% in 2012. Corresponding figures in Sweden were 25.9% and 27.3%. The prevalence of tooth loss was higher among lower than higher educated participants and the gradient was significantly weaker in Sweden than in Norway. Multiple variable analyses adjusting for oral behavioural and attitudinal variables attenuated education related gradients in both cohorts. Conclusion Education related inequality in tooth loss was stronger in the Norwegian than in the Swedish cohort across the survey years. Oral behaviours and attitudinal beliefs played a role in explaining the gradients across time. This illustrates a necessity to promote oral health enhancing behaviours and attitudinal beliefs, particularly so in lower educational groups.publishedVersio

Are 2 Questions Enough to Screen for Depression and Anxiety in Patients With Chronic Low Back Pain?

Study Design. Cross-sectional study. Objective. To examine the sensitivity of 2 single-item questions compared with 2 longer questionnaires for screening depression and anxiety among patients with chronic low back pain (CLBP). Summary of Background Data. Psychosocial factors are frequently identified as risk factors for developing CLBP and as predictors for treatment, and questionnaires are often used to screen for this. Shorter instruments may be easier to use in clinical practice settings. Methods. A total of 564 patients with 2 to 10 months of at least 50% sickness absence due to nonspecific low back pain were assessed for depression and anxiety with the Mini-International Neuropsychiatric Interview (MINI). Single-item questions for depression and anxiety from the Subjective Health Complaint Inventory and 2 longer questionnaires, the Hospital Anxiety and Depression Scale and Hopkins Symptom Checklist–25, were compared with MINI results, considered the “gold standard” in this study. Sensitivity and specificity of single-item and longer questionnaires and receiver operating characteristic curves were compared. Results. According to MINI, the prevalence of anxiety disorders was 12% whereas that of depressive disorders was 4%. The screening questions showed 95% sensitivity and 56% specificity for depressive disorders and 68% sensitivity and 85% specificity for anxiety disorders. The longer questionnaire, Hospital Anxiety and Depression Scale, showed 91% sensitivity and 85% specificity for depressive disorders and 58% sensitivity and 83% specificity for anxiety disorders. Hopkins Symptom Checklist–25 showed 86% sensitivity and 74% specificity for depressive disorders and 67% sensitivity and 87% specificity for anxiety disorders. For 3 of the anxiety disorders and 2 of the depressive disorders, a perfect sensitivity was found between the screening questions and MINI. Conclusions. A single-item screening question was sensitive for depression but less sensitive for anxiety. The screening questions further performed equal to 2 widely used questionnaires. Validation of these results in other populations and compared with other short-item screeners is needed. Level of Evidence:

Dental health personnel’s experience with receiving inquiries from child welfare services: a national cross-sectional study

Objectives To assess if and to what extent public dental health personnel (PDHP) receive inquiries from child welfare services (CWS), and to assess whether PDHP’s experience of receiving inquiries is associated with PDHP’s characteristics and whether the associations are influenced by PDHP’s experience of reporting to CWS. Material and methods Questionnaires were distributed to 1542 PDHP in Norway. Descriptive statistics were used for analysis. Negative-binominal-regression analyses with incidence rate ratios (IRRs) and confidence intervals (CIs) were used to estimate the association between received inquiries from CWS and PDHP characteristics. Results From a total of 1074 respondents, 52.4% had received inquiries from CWS (2012–2014) with a mean number of 3.9 (SD = 4.5). PDHP’s likelihood of receiving inquiries was significantly associated with having many patients, working in small municipalities, working in eastern Norway, having good knowledge of the Health Personnel Act, and having experience reporting to CWS. Regional differences were the only association that varied according to PDHP reporting activity. Conclusions PDHP receive inquiries from the CWS. The likelihood of receiving inquiries is associated with several characteristics of PDHP. To increase PDHP’s likelihood of receiving inquiries, it is important to establish contact between the CWS and PDHS and ensure that the PDHP has good knowledge of the Health Personnel Act.publishedVersio

Dental implant surface temperatures following double wavelength (2780/940 nm) laser irradiation in vitro

Objective: To estimate the implant surface temperature at titanium dental implants during calibrated irradiation using double wavelength laser. Material and methods: A double wavelength laser, 2780 nm Er,Cr:YSGG and 940 nm diode, was calibrated and used to irradiate pristine titanium dental implants, OsseoSpeed, TiUnite and Roxolid SLActive, representing different surface modifications. Initial calibration (21 implants; 7 implants/group) intended to identify optimal wavelength/specific output power/energy that not critically increased the temperature or altered the micro-texture of the implant surface. Subsequent experimental study (30 implants; 10 implants/group) evaluated implant surface temperature changes over 190 s. Irradiation using a computerized robotic setup. Results: Based on the initial calibration, the following output powers/energies were employed: Er,Cr:YSGG laser 18.4 mJ/pulse (7.3 J/cm2)–36.2 mJ/pulse (14.4 J/cm2) depending on implant surface; diode laser 3.3 W (1321.0 W/cm2). During double wavelength irradiation, implant surface temperatures dropped over the first 20 s from baseline 37°C to mean temperatures ranging between 25.7 and 26.3°C. Differences in mean temperatures between OsseoSpeed and TiUnite implants were statistically significant (p < 0.001). After the initial 20 s, mean temperatures continued to decrease for all implant surfaces. The decrease was significantly greater for TiUnite and Roxolid SLActive compared with OsseoSpeed implants (p < 0.001). Conclusion: Calibrated double wavelength laser irradiation did not critically influence the implant surface temperature. During laser irradiation the temperature decreased rapidly to steady-state levels, close to the water/air-spray temperature.publishedVersio

Childhood negative dental experiences and tooth loss in later life:A 25-year longitudinal study in Sweden

OBJECTIVE: To explore the association between childhood NDEs and changes in tooth loss over 25 years among Swedish older adults, and the role of dental visits in explaining such an association.METHODS: We used data from 6154 adults, members of a cohort study that started in 1992 when participants were 50 years old. All data were self-reported through postal questionnaires (6 in total, one every 5 years). Information on childhood NDEs was collected at baseline only. Tooth loss was the repeated outcome measure. Mixed effects logistic regression models were used to test the association between childhood NDEs and tooth loss adjusting for confounders.RESULTS: Childhood NDEs was positively associated with greater odds of experiencing tooth loss and its rate of change over the 25-year period. Although having a dental visit within the past year was positively associated with childhood NDEs and inversely associated with incidence of tooth loss, it explained very little of the association between childhood NDEs and tooth loss in later life.CONCLUSION: The findings underscore the long-lasting damaging effects of early life NDEs on adult oral health.CLINICAL SIGNIFICANCE: A positive patient-dentist relationship starts early in life. Early visits to the dentist are essential to build an enduring relationship of trust between people and healthcare providers.</p

Periodontal referral patterns in Norway: 2003 versus 2018

Objectives Changes in periodontal referral patterns over time have been reported from the United States and Australia. To date, comparable studies have not been published from Europe. The objectives of the present study were to examine changes in periodontal referral patterns in Norway in 2003 versus 2018 and to compare these with trends observed in the United States and Australia using universal criteria for grading of periodontal severity. Materials and methods A retrospective analysis of 369 charts from four Norwegian periodontics clinics was completed. Data on year of referral, gender, age, tobacco smoking, periodontal status and missing teeth at initial examination, teeth planned for extraction, and periodontal case type were collected using a survey format; case type I, II, III, and IV representing increasing severity of periodontitis, case type V representing referral for other periodontal conditions (peri-implantitis, refractory periodontitis, etc.). Chi-square, t-tests, and negative binomial regression were used for the statistical analysis. Results Compared with 2003, the 2018 data showed an increase in mean age at referral (p < 0.05), overall distribution of case type III and V (p = 0.047), and number of missing teeth (p = 0.001). Further, a decrease in prevalence of smokers (p < 0.05), but no change in number of teeth planned for extraction (p = 0.104), were observed. Conclusions During a period of 15 years, changes in periodontal referral patterns in Norway are similar to those in the United States and Australia. The adoption of a guideline-based referral practice might be beneficial for both the dental profession and patients.publishedVersio