Hospital-associated transmission of Brucella melitensis outside the laboratory.

Brucella melitensis was identified in an aspirate obtained from a patient's hip joint during a procedure at a hospital in Canada. We conducted an investigation into possible exposures among hospital workers; 1 worker who assisted with the procedure tested positive for B. melitensis. Aerosol-generating procedures performed outside the laboratory may facilitate transmission of this bacterium.

The impact of premature birth on the mandibular cortical bone of children.

SUMMARY: Children born prematurely often have reduced skeletal mineralization. The aim in this study was to compare the cortical thickness of the lower jaw on radiographs of 8- to 10-year-old children with histories of preterm or full term births. There were no significant differences in cortical thickness between full term and preterm children at this age. INTRODUCTION: The purpose of this study was to compare the cortical thickness of the mandible on panoramic radiographs of 8- to 10-year-old children with histories of preterm or full term births. METHODS: Panoramic radiography was performed on 36 extremely preterm, 38 very preterm and 42 full term children at the age of 8 to 10 years. Five observers independently measured the mandibular cortical width on the panoramic radiographs at four defined sites bilaterally. Altogether, 928 sites were available. Measurements were performed twice on a random 24% of the sites by four observers. One-way analysis of variance with Tukey's post hoc test was used to test differences between groups. Intraclass correlation coefficient (ICC) was calculated for interobserver agreement while intra-observer agreement was expressed as measurement precision. RESULTS: Significant differences of mandibular cortical width were found between extremely preterm and very preterm children for five of the eight measurement sites with the very preterm showing the highest value. No significant differences were found between full term and either very preterm or extremely preterm except for one measurement site, with the extremely preterm showing the lowest value. ICC varied between 0.30 and 0.83 for the different sites (mean 0.62). The precision of a single measurement varied between 0.11 and 0.45 mm (mean 0.25 mm). CONCLUSIONS: From the evidence that very preterm children had significantly thicker mandibular cortices than extremely preterm children, we suggest that these findings may reflect the effect of mineral supplementation provided to premature infants, causing a 'shifting up' of bone mineral status relative to the full term peer group while maintaining the difference between very preterm and extremely preterm born children.

Do patients with osteoporosis have an increased prevalence of periodontal disease? A cross-sectional study.

UNLABELLED: The study examined if women with osteoporosis were at increased risk of periodontal disease. Three hundred eighty females aged 45-65 years with recent dual-energy X-ray absorptiometry (DXA) scans of the spine and proximal femur agreed to a dental examination. No association was established between the presence of severe periodontal disease and osteoporosis. INTRODUCTION: The purpose of this study is to determine whether patients with osteoporosis have an increased severity and extent of periodontal disease, taking full account of confounding factors. METHODS: Volunteer dentate women (45-65 years), who had undergone recent DXA of the femur and lumbar spine, received a clinical examination of their periodontal tissues by a single trained operator who was blind to the subject's osteoporosis status. Clinical examinations were performed within 6 months of the DXA. Basic Periodontal Examination score, gingival bleeding score, periodontal pocket depth, recession and calculus were the periodontal outcome measures. Potential confounding factors were recorded. Logistic regression was performed for the dichotomous outcome measure of severe periodontal disease (present or absent) with osteoporotic status, adjusting for confounding factors. RESULTS: There were 380 dentate participants for whom DXA data were available. Of these, 98 had osteoporosis. When compared with osteoporotic subjects, those with normal bone mineral density were significantly younger (p = 0.01), had a higher body mass index (p = 0.03) and had more teeth (p = 0.01). The prevalence of severe periodontal disease in the sample was 39 %. The unadjusted odds ratio for the association between osteoporosis and severe periodontal disease was 1.21 (0.76 to 1.93). The adjusted odds ratio analysis including other covariates (age, smoking, hormone replacement therapy, alcohol) was 0.99 (0.61 to 1.61). CONCLUSION: No association was established between the presence of severe periodontal disease and osteoporosis.

Rampant host- and defensive phenotype-associated diversification in a goldenrod gall midge.

Natural selection can play an important role in the genetic divergence of populations and their subsequent speciation. Such adaptive diversification, or ecological speciation, might underlie the enormous diversity of plant-feeding insects that frequently experience strong selection pressures associated with host plant use as well as from natural enemies. This view is supported by increasing documentation of host-associated (genetic) differentiation in populations of plant-feeding insects using alternate hosts. Here, we examine evolutionary diversification in a single nominal taxon, the gall midge Asteromyia carbonifera (O.S.), with respect to host plant use and gall phenotype. Because galls can be viewed as extended defensive phenotypes of the midges, gall morphology is likely to be a reflection of selective pressures by enemies. Using phylogenetic and comparative analyses of mtDNA and nuclear sequence data, we find evidence that A. carbonifera populations are rapidly diversifying along host plant and gall morphological lines. At a broad scale, geography explains surprisingly little genetic variation, and there is little evidence of strict co-cladogenesis with their Solidago hosts. Gall morphology is relatively labile, distinct gall morphs have evolved repeatedly and colonized multiple hosts, and multiple genetically and morphologically distinct morphs frequently coexist on a single host plant species. These results suggest that Asteromyia carbonifera is in the midst of an adaptive radiation driven by multitrophic selective pressures. Similar complex community pressures are likely to play a role in the diversification of other herbivorous insect groups.

The relationship between osteoporosis and periodontitis in women aged 45-70 years.

OBJECTIVE: To explore the possible relationship between the osteoporotic condition and the severity of periodontitis in women aged 45-70 years. MATERIALS AND METHODS: Ninety women with generalized chronic periodontitis, aged 45-70 years, were studied. Areal bone mineral density (BMDa) was assessed using standardized dual energy X-ray absorptiometry (normal: T-score ≥ -1, osteopenic: -2.5 ≤ T-score <-1, osteoporotic: T-score < -2.5). Gingival index (GI), bleeding on probing, clinical attachment loss (CAL), probing pocket depth and gingival recession (GR) were recorded. Periodontitis severity was represented by CAL. Menopausal condition and smoking were documented. RESULTS: Mean GI, bleeding on probing, CAL and GR were significantly greater for osteoporotic women than women with normal BMDa (P = 0.002, P = 0.01, P = 0.04, respectively). Osteopenic women and women with normal BMDa significantly differed in mean GI (P = 0.02). The associations found between osteoporotic women and women with normal BMDa and the associations found between osteopenic women and women with normal BMDa existed even after adjusting for smoking and menopausal status. CONCLUSION: Subjects with osteoporosis (OPR) presented with greater CAL than the subjects with normal BMDa, which suggests a greater severity of periodontitis. Subjects with OPR had greater GR than the subjects with normal BMDa. Subjects with osteopenia and subjects with normal BMDa did not differ in CAL, which might suggest that the early diagnosis of reduced BMDa, prior to the establishment of a significant negative impact on the periodontal tissues, might be important. Smoking and menopausal status did not alter these associations.

Students' perception of the prognosis for a single-surface amalgam restoration.

The aim of the study was to assess the self-rated skill, clinical judgement and competency of final-year pre-doctoral dental students. The study was also designed to determine whether the students' estimated durability of their single-surface restorations was determined by their confidence. Students were given a questionnaire and completed it anonymously. One hundred and ninety-six forms were returned from the 238 students (82% return rate). Complete analysis was possible on 169 questionnaires. The students' self-assessed skill and judgement were a significant factor in predicting how long they would tell a patient that their restoration would last. Those ranking themselves below average were more likely to state that their amalgam restorations would have a shorter life (odds increased by 2.82 for those ranking themselves lower than most others). There was a significant association between the students' self-assessed skill and judgement and their confidence in dealing with both the initial management of patients' medical emergencies (ρ = 0.244, P = 0.001, n = 191) and their general confidence in dealing with medical emergencies (ρ = 0.187, P = 0.01, n = 188). Given a conversational scenario with a patient, the treatment prognosis given by final-year pre-doctoral students for a single-surface amalgam restoration was dependent on their self-assessed competence, skill and judgement.

Changes in mandibular cortical width measurements with age in men and women.

UNLABELLED: Automated software was used to measure the mandibular cortical width in a large sample of dental radiographs. We determined that cortical thinning normally starts in women at age 42.5 years and accelerates thereafter. We can estimate population referral rates and thus enable cost benefit analyses for osteoporosis detection by dentists. INTRODUCTION: Previous studies have shown that the mandibular cortical width is significantly correlated with the bone mineral density at sites which may undergo osteoporotic fracture, e.g. hip. Mandibular cortical width can be determined automatically from dental panoramic radiographs that dentists frequently request, using appropriate software. We study the distribution of cortical width given age to predict those patients requiring further investigation for osteoporosis. METHODS: The mandibular cortical width was measured in 4,949 dental panoramic tomograms, in patients aged 15-94 years. The inferior and superior cortical edges were detected automatically using a global active shape model image search, followed by an active appearance model search. Nonparametric statistical analysis and nonlinear piecewise linear/quadratic regression were used to analyse the data. RESULTS: For females, the mean cortical width had a linear increase before the age of 17 years, a period of no change (estimate = 3.25 mm, se = 0.01) until the age of 42.5 years, followed by a quadratic decrease with age. For males, it had a linear increase before the age of 19 years, a constant value (estimate = 0.37 mm, se = 0.01) until the age of 36 years and then a slow linear decrease. The rate of decrease in mean cortical width goes from 0.049 to 0.105 standard deviations per year in the 60-80-year-old female age group, in line with published bone mineral density T-score reductions. CONCLUSIONS: The pattern of decrease in mandibular cortical width with age was similar to the known pattern of bone loss from the hip, accelerating in women after the age of 42.5 years.

The osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces in rats.

BACKGROUND AND OBJECTIVE: The enhancing effects of chitosan on activation of platelets and differentiation of osteoprogenitor cells have been demonstrated in vitro. The purpose of this study was to evaluate the in vivo osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces. MATERIAL AND METHODS: Chitosan-collagen composites containing chitosan of different molecular weights (450 and 750 kDa) were wrapped onto titanium implants and embedded into the subcutaneous area on the back of 15 Sprague-Dawley rats. The control consisted of implants wrapped with plain collagen type I membranes. Implants and surrounding tissues were retrieved 6 wks after surgery and identified by Alizarin red and Alcian blue whole mount staining. The newly formed structures in the test groups were further analyzed by Toluidine blue and Masson-Goldner trichrome staining, and immunohistochemical staining with osteopontin and alkaline phosphotase. The bone formation parameters of the new bone in the two test groups were measured and compared. RESULTS: New bone formed ectopically in both chitosan-collagen groups, whereas no bone induction occurred in the negative control group. These newly formed bone-like structures were further confirmed by immunohistochemical staining. Comparison of bone parameters of the newly induced bone revealed no statistically significant differences between the 450 and 750 kDa chitosan-collagen groups. CONCLUSION: Our results demonstrated that chitosan-collagen composites might induce in vivo new bone formation around pure titanium implant surfaces. Different molecular weights of chitosan did not show significantly different effects on the osteoinductive potential of the test materials.

Designing cobalt chromium removable partial dentures for patients with shortened dental arches: a pilot survey.

The aim of this survey was to investigate the quality of prescription for the fabrication of cobalt chromium removable partial dentures (RPDs) that are used to extend the shortened dental arches (SDAs). A survey of four commercial dental laboratories located in northern England was conducted. The target of this survey was cobalt chromium RPDs that were requested to restore SDAs comprising the anterior teeth and 2-4 premolars. Dentists' prescriptions were scrutinised, and a special data collection form was completed accordingly. A total of 94 dentists' prescriptions and associated SDA casts were examined. Almost all the requested cobalt chromium RPDs were clasp-retained RPDs (97%). Scrutinising the 91 prescriptions for clasp-retained cobalt chromium RPDs showed that dentists' prescriptions did not have any instructions about the design of the partial denture in a considerable proportion of the cases (32%). Teeth to be clasped were identified clearly in 45% of the prescriptions. A majority of the dentists (64%) failed to provide any instructions about the design of the rests to be placed on the most posterior premolar abutment teeth. A considerable proportion of the dentists delegated the task of selecting the type of the major connector to the dental technician (41%). Only 21 (23%) of the examined casts had clearly defined rest seat preparation. The outcome of this pilot survey shows inadequate quality of prescription in designing RPDs for patients with SDAs. This finding has an ethical and clinical bearing and does not fit with current legal guidelines relevant to designing RPDs.

Healing of tooth extraction sockets in the streptozotocin diabetic rat model: Induction of cartilage by BMP-6.

Cartilage does not form in the tooth extraction socket of the normal rat. The aim of the study was to determine if adding BMP-6 to the extraction socket would cause chondrogenic differentiation in the diabetic rat. A group of 8-week-old rats were injected intraperitoneally with a diabetogenic agent, streptozotocin, and a control group received citrate buffer only. Three weeks later, the maxillary molar teeth were extracted and either BMP-6 or saline applied to the extraction sockets. Rats from each group were killed on days 3, 5, 7, and 9 after tooth extraction. In the diabetic rats treated with BMP-6, there was a cellular subperiosteal reaction at day 3 in the extra-alveolar tissues, which by day 7 had formed a large mass of cartilage. Cartilage was induced in the subperiosteal region of the socket extra-alveolar bone following the application of BMP-6 in the diabetic rat.

Dental health state utility values associated with tooth loss in two contrasting cultures.

The study aimed to assess the value placed on oral health states by measuring the utility of mouths in which teeth had been lost and to explore variations in utility values within and between two contrasting cultures, UK and Iran. One hundred and fifty eight patients, 84 from UK and 74 from Iran, were recruited from clinics at University-based faculties of dentistry. All had experienced tooth loss and had restored or unrestored dental spaces. They were presented with 19 different scenarios of mouths with missing teeth. Fourteen involved the loss of one tooth and five involved shortened dental arches (SDAs) with varying numbers of missing posterior teeth. Each written description was accompanied by a verbal explanation and digital pictures of mouth models. Participants were asked to indicate on a standardized Visual Analogue Scale how they would value the health of their mouth if they had lost the tooth/teeth described and the resulting space was left unrestored. With a utility value of 0.0 representing the worst possible health state for a mouth and 1.0 representing the best, the mouth with the upper central incisor missing attracted the lowest utility value in both samples (UK = 0.16; Iran = 0.06), while the one with a missing upper second molar the highest utility values (0.42, 0.39 respectively). In both countries the utility value increased as the tooth in the scenario moved from the anterior towards the posterior aspect of the mouth. There were significant differences in utility values between UK and Iranian samples for four scenarios all involving the loss of anterior teeth. These differences remained after controlling for gender, age and the state of the dentition. With respect to the SDA scenarios, a mouth with a SDA with only the second molar teeth missing in all quadrants attracted the highest utility values, while a mouth with an extreme SDA with both missing molar and premolar teeth in all quadrants attracted the lowest utility values. The study provided further evidence of the validity of the scaling approach to utility measurement in mouths with missing teeth. Some cross-cultural variations in values were observed but these should be viewed with due caution because the magnitude of the differences was small.

Prevalence of distal surface caries in the second molar among referrals for assessment of third molars: a systematic review and meta-analysis.

We conducted a systematic review of epidemiological studies to assess the prevalence of distal surface caries (DSC) in second molars adjacent to third molars. We searched the Cochrane Library, Lilacs, Embase, and Medline through Ovid® (Wolters Kluwer) to retrieve English and non-English papers from inception to June 2016, and supplemented this with a search of the references and by tracking citations. Three reviewers contributed: one reviewed all the papers, and the other two divided the rest between them. They extracted data, completed structured quality assessments with a validated risk of bias tool for observational studies, and categorised the summary scores. The search yielded 81 records and 11 studies were analysed. The considerable methodological diversity meant that five were not eligible for inclusion in the quantitative synthesis. A meta-analysis of six studies on the prevalence of DSC and a subgroup analysis of three on various third-molar angulations were indicated. The overall pooled prevalence estimate calculated with a random-effects model was 23% (95% CI 2% to 44%) among patients. Prevalence subtotals were 20% (95% CI 5% to 36%) for prospective, and 15% (95% CI 5% to 36%) for retrospective studies among teeth. A subgroup analysis of three studies with 1296 patients (1666 molars) yielded a prevalence of DSC of 36% (95% CI 5% to 67%) for mesial impactions and 22% (95% CI 1% to 42%) for horizontal impactions. DSC was present in 3% of distally-inclined impactions, (95% CI 1% to 5%) and in 7% (95% CI 1% to 13%) of vertical third molars. The studies varied. The risk of bias was low in one and moderate in two. European studies suggested that DSC may be present in about one in four referrals for the assessment of third molars, and that the risk is considerably higher in those with convergent third molar impactions.

Detecting the earliest radiological signs of bisphosphonate-related osteonecrosis.

Introduction Oral bisphosphonates are the most commonly prescribed anti-resorptive drugs used in the treatment of osteoporosis, but osteonecrosis of the jaw is a serious complication. The early diagnosis of this destructive side effect is crucial in preventing excessive bone loss, pain and infection.Objective To aid dental practitioners in the early identification of bisphosphonate-related osteonecrosis of the jaw.Method A scoping review was carried out.Data sources We searched MEDLINE via OVID, EMBASE via OVID, Dentistry and Oral Sciences Source (DOSS), Proquest Dissertation and Theses Search, to identify references that described clinical and radiological findings in medication-related osteonecrosis of the jaw (MRONJ).Data selection Nineteen references mentioned the earliest radiological changes in MRONJ with a description of the observations and were included in the analysis.Data synthesis The radiographic signs included osteosclerosis/lysis, widening of the periodontal ligament and thickening of the lamina dura and cortex. To assess the quality of original data on which recommendations had been made, these 19 studies were subjected to a quality appraisal.Conclusion Using bone exposure as a criterion for diagnosis of MRONJ, leads to delayed diagnosis and a poor response to treatment. In those patients at risk of bone exposure with MRONJ, insufficient information is present in the literature to allow the general dental practitioner to reliably identify the radiographic features indicating imminent bone exposure. A well-designed prospective study is needed.

Randomized controlled trial of chlorhexidine gluconate for washing, intranasal mupirocin, and rifampin and doxycycline versus no treatment for the eradication of methicillin-resistant Staphylococcus aureus colonization.

BACKGROUND: Eradication of methicillin-resistant Staphylococcus aureus (MRSA) carriage may reduce the risk of MRSA infection and prevent transmission of the organism to other patients. METHODS: To determine the efficacy of decolonization therapy, patients colonized with MRSA were randomized (3:1 allocation) to receive treatment (2% chlorhexidine gluconate washes and 2% mupirocin ointment intranasally, with oral rifampin and doxycycline for 7 days), or no treatment. Follow-up samples for MRSA culture were obtained from the nares, perineum, skin lesions, and catheter exit sites monthly for up to 8 months. The primary outcome measure was detection of MRSA at 3 months of follow-up. Univariate and multivariable analyses were performed to identify variables associated with treatment failure. RESULTS: Of 146 patients enrolled in the study, 112 patients (87 treated; 25 not treated) were followed up for at least 3 months. At 3 months of follow-up, 64 (74%) of those treated had culture results negative for MRSA, compared with 8 (32%) of those not treated (P=.0001). This difference remained significant at 8 months of follow-up, at which time, 54% of those treated had culture results negative for MRSA (chi2=64.4; P<.0001, by log-rank test). The results of the multivariable analysis indicated that having a mupirocin-resistant isolate at baseline was associated with treatment failure (relative risk, 9.4; 95% confidence interval, 2.8-31.9; P=.0003), whereas decolonization therapy was protective (relative risk, 0.1; 95% confidence interval, 0.04-0.4; P=.0002). Mupirocin resistance emerged in only 5% of follow-up isolates. CONCLUSIONS: Treatment with topical mupirocin, chlorhexidine gluconate washes, oral rifampin, and doxycycline for 7 days was safe and effective in eradicating MRSA colonization in hospitalized patients for at least 3 months.

Development of cellular and humoral immunity in the respiratory tract of rabbits to Pseudomonas lipopolysaccharide.

Immunization with Pseudomonas lipopolysaccharide induced both cellular and humoral immunity in rabbits, particularly in the respiratory tract after intranasal immunization. Either parenteral (i.m.) or intranasal immunization elicited an IgG antibody response in respiratory secretions, but only intranasal immunization produced secretory IgA antibody. Immunization by both routes stimulated serum IgM and IgG agglutinative antibodies. Because both methods of immunization produced skin test reactivity which had components of both Arthus and tuberculin-like reactions, cellular immunity was more readily assessed by the measurement of migration inhibitory factor (MIF) released from immune lymphocytes in respiratory and spleen cell suspensions after challenge with the lipopolysaccharide antigen. After intranasal vaccination, MIF activity was detected in the respiratory tract by direct assay; in contrast, i.m. immunized rabbits did not produce respiratory MIF. Both modes of immunization resulted in splenic MIF activity. However, lymphocytes were only capable of producing MIF for short periods after primary immunization had ended, apparently losing this function in about 2-3 wk. Therefore, it was concluded that cellular immunity by in vitro assay was transient after primary immunization with this Pseudomonas antigen in contrast to the more persistent humoral immunity. The biological significance of immune lymphocytes as part of the coordinated host defense of the lung needs further evaluation.

Automated osteoporosis risk assessment by dentists: a new pathway to diagnosis.

General dental practitioners use a vast amount of panoramic radiography in their routine clinical work, but valuable information about patients' osteoporotic status is not collected. There are many reasons for this, but one of the prime reasons must be the disruption involved in clinical routine with lengthy manual radiographic assessment. We have developed computer software, based on active shape modeling that will automatically detect the mandibular cortex on panoramic radiographs, and then measure its width. Automatic or semi-automatic measurement of the cortical width will indicate the osteoporotic risk of the patient. The aim of our work was to assess the computer search technique's ability to measure the mandibular cortical width and to assess its potential for detection of osteoporosis of the hip, spine and femoral neck. Mandibular cortical width was measured using the manually initialized (semi-automatic) method and, when assessed for diagnosing osteoporosis at one of the three measurement sites, gave an area under the ROC curve (A(z))=0.816 (95% CI=0.784 to 0.845) and for the automatically initialized searches, A(z)=0.759 (95% CI=0.724 to 0.791). The difference between areas=0.057 (95% Confidence interval=0.025 to 0.089), p<0.0001. For diagnosing osteoporosis at the femoral neck, mandibular cortical width derived from the manually initialized fit gave an area under the ROC curve (A(z))=0.835 (95% CI=0.805 to 0.863) and for the automatically initialized searches A(z)=0.805 (95% CI=0.773 to 0.835). The difference in A(z) values between active shape modeling search methods=0.030 (95% CI=-0.010 to 0.070), and this was not significant, p=0.138. We concluded that measurement of mandibular cortical width using active shape modeling is capable of diagnosing skeletal osteoporosis with good diagnostic ability and repeatability.

Accuracy in osteoporosis diagnosis of a combination of mandibular cortical width measurement on dental panoramic radiographs and a clinical risk index (OSIRIS): the OSTEODENT project.

Clinical questionnaires and dental radiographic findings have both been suggested as methods of identifying women at risk of having osteoporosis and who might benefit from bone densitometry. The aim of this study was to measure the diagnostic accuracy of a combination of mandibular cortical width (MCW) measured from dental panoramic radiographs (DPRs) and the osteoporosis index of risk (OSIRIS) in the diagnosis of osteoporosis. 653 women (age range 45-70 years, mean age 54.95 years) in four European centres underwent standardised dual X-ray energy absorptiometry (DXA) to provide reference data on osteoporosis status. Each subject was interviewed to derive OSIRIS scores and underwent DPR examination. MCW was measured directly by five observers. Receiver Operating Characteristic (ROC) curve analysis was used to calculate sensitivities and specificities of the clinical and radiographic tests for the diagnosis of osteoporosis. 512 (78.4%) of the study population were classified as having normal BMD and 141 (21.6%) as having osteoporosis. Using ROC analysis, OSIRIS gave a ROC curve area (A(z)) of 0.838, with a sensitivity of 70.9% and a specificity of 79.5% at a diagnostic threshold of

Prediction of bone mineral density with dental radiographs.

There is consensus to use the bone mineral density (BMD) for the operational definition of the degree of osteoporosis and the risk of osteoporotic fractures. Dual X-ray absorptiometry (DXA) is the common technique to determine BMD. Because of high costs and limited availability of DXA equipment it is worthwhile to look for alternative diagnostic techniques. As part of a larger study, the Osteodent project, we investigated if the trabecular pattern on dental radiographs can be used to predict BMD and to identify the subjects with osteoporosis and increased risk of osteoporotic fractures. In four clinical centers 671 women with an average age of 55 years were recruited. BMD values were measured by DXA equipment at the femoral neck, total hip, and spine. One panoramic and two intraoral radiographs were made. From 525 women a complete set of BMD values and radiographs was obtained. Four regions of interest on the radiographs were selected manually and then processed automatically. On all regions of interest mean and standard deviation of the gray values were measured and several features describing the shape of the binarized trabecular pattern. Multiple regression was used to predict BMD of total hip and spine by means of the radiographic measurements combined with age. It was found that age accounts for 10% of the variation in total hip BMD and 14% of the variation in spinal BMD. When all measurements on the dental radiographs are used the explained variation increases to 22% and 23%. The areas under the ROC curves are comparable to those of commonly used screening instruments for osteoporosis. It is concluded that prediction of DXA measurements of BMD by means of quantitative analysis of the trabecular pattern on dental radiographs is feasible.

It's not just about the mask.

Occupational health and infection prevention and control should utilize both the precautionary principal and the scientific literature to ensure staff safety during an Influenza Pandemic. The literature indicates that N95 respirators should be used whenever the mode of transmission is not clearly understood. However, focusing just on the type of respiratory protection while necessary is not sufficient. A multi-pronged approach to staff safety should be used when planning for an Influenza Pandemic. This includes the implementation of Routine Practices and Additional Precautions in all healthcare institutions, optimal hand hygiene, fit-tested N95 respirators for staff providing direct care to patients with a virus of unknown epidemiology or which is known to be transmitted by the airborne route, vaccination of all staff when an effective vaccine is available and chemoprophylaxis against Influenza A. Patients will be best cared for when workers believe that everything possible is being done to protect their health.

Guidelines on the timing and frequency of bitewing radiography: a systematic review.

Objectives To identify guidelines on when and how frequently bitewing radiographs should be used in dentistry for the diagnosis of caries, and to provide an objective appraisal of their quality.Data sources MEDLINE (OVID), US National Guideline Clearinghouse (www.guideline.gov) and the Royal College of Surgeons of England (https://www.rcseng.ac.uk/fds/publications-clinical-guidelines/clinical_guidelines) websites were searched using a variety of relevant search terms (2 August 2016).Data selection Publications were included if they made recommendations on the issue of when and how frequently radiographs should be used in any dentally-related specialty pertaining to the diagnosis of caries; and/or if they were aimed at the individual practitioner (any health professional working within dentistry) and/or patients.Data analysis Thirteen published guidelines were included and assessed using the AGREE II instrument.Conclusions There was a significant variation amongst the guidelines in the recommendations at what age radiography should be undertaken. There was also disagreement on the frequency of repeat radiographs and how this is influenced by the age of the patient and their caries risk.