In-vitro comparison of bonding time and strength of adhesive pre-coated and standard metal orthodontic brackets

To compare the shear bond strength and bond time of 3M Unitek's APC (Adehesive Pre-Coated) Flash-Free™system applied to metal brackets. An in vitro study was performed on 40 extracted sound human premolar teeth randomly divided into two groups (20 per group) bonded either with Adhesive Pre-Coated Flash-Free metal brackets or metal brackets coated manually with Transbond XT™ light-cure adhesive. Bonding time was measured using a stopwatch. Thermoycling was performed on the samples (500 cycles) to simulate the oral environment between baths of 5°C and 55°C distilled water. Debonding shear bond strength measurements were performed in an Instron universal testing machine. The APC Flash-Free group bonded in significantly (p<0.001) less time (mean 34.06s/tooth) than the manually coated group (mean 55.14s/tooth). Shear bond strength of the manually coated group was significantly (p<0.001) higher (mean 13.32 MPa) than the APC Flash-Free group (mean 10.95 MPa). The APC Flash-Free free system is efficient and allows for reduced chair time during the bonding appointment while attaining a mean shear bond strength of 10.95MPa, which is higher than the minimum shear bond strength of between 4MPa and 7MPa

Development of a clinical prediction model for high hospital cost in patients admitted for elective non-cardiac surgery to a private hospital in South Africa

INTRODUCTION : Clinicians may find early identification of patients at risk for high cost of care during and after surgery useful, to prepare for focused management that results in optimal clinical outcome. The aim of the study was to develop a clinical prediction model to identify high and low hospital cost outcome after elective non-cardiac surgery using predictors identified from a preoperative self-assessment questionnaire. METHODS : Data to develop a clinical prediction model were collected for this purpose at a private hospital in South Africa. Predictors were defined from a preoperative questionnaire. Cost of hospital admission data were received from hospital administration, which reflected the financial risk the hospital carries and which could be reasonably attributed to a patient’s individual clinical risk profile. The hospital cost excluded fees charged (by any healthcare provider), and cost of prosthesis and other consignment items that are related to the type of procedure. The cost outcome measure was described as cost per total Work Relative Value Units (Work RVUs) for the procedure, and dichotomised. Variables that were associated with the outcome during univariate analysis were subjected to a forward stepwise regression selection technique. The prediction model was evaluated for discrimination and calibration, and internally validated. RESULTS : Data from 770 participants were used to develop the prediction model. The number of participants with the outcome of high cost were 142/770 (18.4%). The predictors included in the full prediction model were type of surgery, treatment for chronic pain with depression, and activity status. The area under the receiver operating curve (AUROC) for the prediction model was 0.83 (95% confidence interval [CI]: 0.79 to 0.86). The Hosmer–Lemeshow indicated goodness-of-fit (p = 0.967). The prediction model was internally validated using bootstrap resampling from the development cohort, with a resultant AUROC of 0.86 (95% CI: 0.82 to 0.89). CONCLUSION : The study describes a clinical risk prediction model developed using easily collected patient-reported variables and readily available administrative information. The prediction model should be validated and updated using a larger dataset, and used to identify patients in which cost-effective care pathways can add value.Supplement 1: Patient information and self-assessment questionnaire.Supplement 2: Binary outcome definition.Supplement 3: Table – Use of self-assessment questions to define predictor variables.Supplement 4: Table – Information on cases with extreme values excluded from derivation cohort.The South African Society of Anaesthesiologists (SASA) Jan Pretorius Research Fund; University of Pretoria, Faculty of Health Sciences, School of Medicine – research assistant grant; The SASA Acacia Branch Committee.http://www.sajaa.co.zadm2022Anaesthesiolog

Variations in the anatomical dimensions of the mandibular ramus and the presence of third molars : its effect on the sagittal split ramus osteotomy

The authors undertook a prospective study to evaluate the influence that the anatomical dimensions of the ramus of the mandible and the presence of lower third molar teeth may have on the sagittal split ramus osteotomy. The anatomical dimensions measured included the width of the anterior mandibular ramus, the height of the corpus posterior to the second mandibular molar and the antero-posterior anatomical position of the lingual. The influence that these dimensions of the mandible may have on the successful splitting of the mandibular ramus wasThe effect that the presence of wisdom teeth had on the difficulty of the procedure was also investigated. This study found that, unlike the presence of third molars, there was no single anatomical measurement that contributed to the level of difficulty of the sagittal split osteotomy. For descriptive purposes the authors proposes a classification of the four typical patterns of unfavourable splits.http://www.sciencedirect.comhb201

The impact of a change in work posture from seated to stand-up on work-related musculoskeletal disorders among sewing-machine operators

BACKGROUND : Work‐related postural change could lead to improved musculoskeletal health. METHOD(S) : In a quantitative, retrospective, longitudinal study, data of work‐related musculoskeletal disorders of 123 sewing‐machine operators were captured for 4.5 years, and analysed using Poisson regression. RESULTS : Stand‐up work posture (SUWP) reduced the incidence for spinal disorders (SD) to 0.29 fold the incidence for sitting work posture (SWP) (P < 0.001). Morbid obesity had significantly increased (P = 0.04) incidence of upper limb disorders (ULD), 3.35 times that of normal body mass index (BMI) (regardless of work posture). SUWP was associated with increased IRR (1.49) for lower limb disorders (LLD). LLDs were associated with obesity (overweight (IRR = 2.58; P = 0.08), obese (IRR = 2.45; P = 0.09), and morbidly obese (IRR = 6.24; P = 0.001)). CONCLUSIONS : The protective benefit of the SUWP was statistically significant for SD incidence. Owing to high mean BMI, SUWP had a negative impact on the incidence of LLDs for the first 2 monthshttp://wileyonlinelibrary.com/journal/ajim2019-08-01hj2018Physiotherap

The effectiveness of the pregnancy adapted YEARS algorithm to safely identify patients for CT pulmonary angiogram in pregnant and puerperal patients suspected of having pulmonary embolism

BACKGROUND: Pulmonary thromboembolism is one of the leading causes of maternal death worldwide. Globally there has been increasing physician reliance on CT pulmonary angiogram for definitive diagnoses and exclusion of pulmonary thromboembolism. The problem, however, arises when considering the high radiation penalty from performing these investigations, highlighted by the low diagnostic yield. Of recent, the pregnancy-adapted YEARS algorithm has shown promise in international studies as a possible alternative for stratifying risk of pulmonary thromboembolism during the pregnancy and puerperal period. OBJECTIVES: To determine the effectiveness of the pregnancy adapted YEARS algorithm to safely minimise the number of true negative CT pulmonary angiograms for patients suspected of having pulmonary embolism in our clinical setting. METHOD: A cross-sectional study was performed in a tertiary hospital in Gauteng on puerperal and pregnant patients suspected of having pulmonary embolism. We retrospectively applied the pregnancy adapted YEARS algorithm and reviewed the various outcomes. RESULTS: The pregnancy adapted YEARS algorithm proved effective in safely identifying patients for CT pulmonary angiography. By retrospectively applying the algorithm, there could have been a 25.7% scan reduction, whilst maintaining a negative predictive value of 100.0%. CONCLUSION: As physician reliance on radiological investigations increases, we must remain cognisant of the added radiation exposure and the long-term adverse effects of ionising radiation. The pregnancy-adapted YEARS algorithm provides a safe, reproducible alternative to aid our bid going forward.Principal investigatorhttp://www.sajr.org.za/index.php/sajrdm2022RadiologyStatistic

Caesarean section indications and outcomes at a tertiary level hospital in South Africa

Caesarean section rates have increased over the past 30 years and there has been lack of understanding of the drivers of these increased rates. The World Health Organisation has recommended the use of the Robson ten group classification as a system for assessing, monitoring, and comparing caesarean section rates at all levels. AIM : The aim of this study was to determine the indications and caesarean section rate at a tertiary referral hospital. METHODS : This was a retrospective analysis of deliveries between 1 January 2014 and 31 December 2018 at a tertiary level hospital in Pretoria, South Africa. The Robson’s 10 group classification was used in classifying the caesarean sections. RESULTS : A total of 15 295 deliveries took place during the study period: 6 883 women delivered vaginally (NVD) and 8 412 women by caesarean sections (CS). The average CS rate was 55%. Robson’s 10 Group 5 (all multiparous, ≥1 previous CS, ≥ 37 weeks, single cephalic pregnancy) was the greatest contributor to the CS rate (29%). Most women who delivered were between the ages 20-35yrs (n= 12000, 78.6%), with majority delivering via CS deliveries (n=6616, 55.1%) compared to NVDs (n=5388, 44.9%). The CS rate for women with underlying medical disease was 19% and women with hypertensive disorders of pregnancy were the largest contributor to this group (n=1241, 14.8%). The caesarean section rate for women classified as a maternal near miss was 69.6%. There was no statistically significant difference in the rate of postpartum haemorrhage between women who delivered vaginally NVD (n=173) compared to those who delivered by CS (n=245) p=0.132). CONCLUSION : Strategies to reduce the primary caesarean deliveries and steps to improve VBAC success rates should be considered and implemented. In a tertiary hospital, Robson’s 10 group classification alone does not give a full description of the caesarean section rate; other causes like medical conditions need to be considered. Health care workers should follow local guidelines to reduce the risk of complications related to hypertensive disorders in pregnancy.https://journals.co.za/journal/medogam2022Obstetrics and Gynaecolog

Mortality and morbidity of very low-birthweight and extremely low-birthweight infants in a tertiary hospital in Tshwane

BACKGROUND: Since 2000, South Africa (SA) has had a relatively static neonatal mortality rate, estimated to be 12/1 000 live births, with complications of prematurity being the leading cause of neonatal mortality. Survival to hospital discharge of small infants has improved over the last few decades; however, this is more marked in developed countries where neonatal intensive care, nasal continuous positive airway pressure, mechanical ventilation and surfactant are available to the majority of infants. OBJECTIVES: The primary objective was to determine overall mortality of very low-birthweight and extremely low birthweight (ELBW) infants in the neonatal unit at Steve Biko Academic Hospital (SBAH). Secondary objectives were to determine the frequency of major morbidities, identify factors associated with morbidity and mortality, determine survival without major morbidity, and whether birthweight can accurately predict outcome. METHODS: This was a retrospective cross-sectional study of infants with a birthweight of 500 - 1 499 g who had been admitted to the neonatal unit of SBAH between June 2016 and May 2017. RESULTS: Overall survival to hospital discharge was 75.7%, with only 17.7% of infants weighing <750 g surviving. Survival without major morbidity was 35.1%. Small-for-gestational age, invasive ventilation, and culture-positive early-onset sepsis were associated with an increased risk of mortality, whereas higher birthweight and the use of nCPAP decreased mortality in multivariable analysis. CONCLUSION: Although the overall survival of infants weighing <1 500 g is comparable to other large SA public hospitals, survival of ELBW infants is poor, while these are the infants that require the most interventions, placing a heavy burden on limited resources. However, it remains difficult to recommend a cut-off weight for potentially life-saving interventions.http://www.sajch.org.zapm2020Paediatrics and Child Healt

Determinants, outcomes and costs of ceftriaxone v. amoxicillin-clavulanate in the treatment of community-acquired pneumonia at Witbank Hospital

BACKGROUND. Community-acquired pneumonia (CAP) is a major cause of death and morbidity worldwide. Treatment is centred on antibiotics with ceftriaxone and amoxicillin-clavulanate being some of the most commonly prescribed agents. Objective. To compare treatment outcomes and costs in patients receiving either of these two antibiotics at Witbank Hospital (WH). METHODS. A total of 200 randomly selected adult patient files (100 receiving ceftriaxone and 100 amoxicillin-clavulanate) recording a diagnosis of CAP were studied to determine the length of hospital stay, comorbid conditions and treatment outcomes. A descriptive and comparable analysis was performed. RESULTS. Male gender, higher CURB-65 scores and death were associated with the use of ceftriaxone. Severity of disease and previous antibiotic exposure influenced the duration of hospital admission. CONCLUSION. Gender and severity of disease (based on the CURB-65 score) were the determinants of antibiotic choice at WH. Male gender increased the likelihood of being treated with ceftriaxone, as did a CURB-65 score of >2. There were no differences in the outcomes of CAP patients treated with ceftriaxone compared with those treated with amoxicillin-clavulanate. Irrespective of antibiotic used, gender and severity of disease influenced treatment outcomes. Male gender was associated with a higher mortality and longer hospital stay. The average duration of stay for both antibiotics was not significantly different. Thus, only level 1 and 2 costs need to be considered when comparing the two regimens. On this basis, ceftriaxone was cheaper than amoxicillin-clavulanate.http://www.samj.org.zaam201

Soft tissue thickness values for black and coloured South African children aged 6-13 years

In children, craniofacial changes due to facial growth complicate facial approximations and require specific knowledge of soft tissue thicknesses (STT). The lack of South African juvenile STT standards of particular age groups, sex and ancestry is problematic. According to forensic artists in the South African Police Service the use of African-American values to reconstruct faces of Black South African children yields poor results. In order to perform a facial approximation that presents a true reflection of the child in question, information regarding differences in facial soft tissue at different ages, sexes and ancestry groups is needed. The aims of this study were to provide data on STT of South African Black and Coloured children and to to assess differences in STT with respect to age, sex and ancestry. STT was measured using cephalograms of South African children (n = 388), aged 6 – 13 years. After digitizing the images, STT measurements were taken at ten mid-facial landmarks from each image using the iTEM measuring program. STT comparisons between groups per age, sex and ancestry were statistically analyzed. The results showed that STT differences at lower face landmarks are more pronounced in age groups per ancestry as opposed to differences per age and sex. Generally, an increase in STT was seen between 6 - 10 year old groups and 11 -13 year old groups, regardless of ancestry and sex, at the midphiltrum, labiale inferius, pogonion, and beneath chin landmarks. This research created a reference dataset for STT of South African children of Black and Coloured ancestry per age and sex that will be useful for facial reconstruction / approximation of juvenile remains.http://www.elsevier.com/locate/forsciint2016-07-31hb2016Anatom