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Sökning: WFRF:(Horner Keith) > (2006-2009)

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1.
  • Allen, P Danny, et al. (författare)
  • Detecting reduced bone mineral density from dental radiographs using statistical shape models
  • 2007
  • Ingår i: IEEE transactions on information technology in biomedicine. - : Institute of Electrical and Electronics Engineers (IEEE). - 1089-7771 .- 1558-0032. ; 11:6, s. 601-610
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe a novel method of estimating reduced bone mineral density (BMD) from dental panoramic tomograms (DPTs), which show the entire mandible. Careful expert width measurement of the inferior mandibular cortex has been shown to be predictive of BMD in hip and spine osteopenia and osteoporosis. We have implemented a method of automatic measurement of the width by active shape model search, using as training data 132 DPTs of female subjects whose BMD has been established by dual-energy X-ray absorptiometry. We demonstrate that widths measured after fully automatic search are significantly correlated with BMD, and exhibit less variability than manual measurements made by different experts. The correlation is highest towards the lateral region of the mandible, in a position different from that previously employed for manual width measurement. An receiver-operator characterstic (ROC) analysis for identifying osteopenia (T < -1: BMD more than one standard deviation below that of young healthy females) gives an area under curve (AUC) value of 0.64. Using a minimal interaction to initiate active shape model (ASM) search, the measurement can be made at the optimum region of the mandible, resulting in an AUC value of 0.71. Using an independent test set, AUC for detection of osteoporosis (T < -2.5) is 0.81.
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2.
  • Christell, Helena, et al. (författare)
  • Economic evaluation in oral health care
  • 2009
  • Ingår i: Programme and abstract book. ; , s. 70-70
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Introduction Economic evaluation attempts to weigh costs and effects of alternative interventions with the goal that available resources are used to achieve maximum benefits for patients in terms of health and quality of life. In emerging technologies this is particularly important to avoid inappropriate and excessive use. Objectives To analyse evidence on economic evaluation in oral health care, particularly on diagnostic imaging methods, by systematic review. Material and methods A search for literature was made starting with a hand made search according to the pearl growing model. This search strategy means that articles and relevant literature are retrieved by talking to renowned specialists in the subject area and by finding indexing and MeSH terms by looking at those articles and their reference lists. From seven articles indexing terms and MeSH terms were chosen and searches were made from PubMed, the Cochrane Library and Science Citations Index. The retrieved primary studies that according to the abstract contained a cost-effectiveness analysis were interpreted by two reviewers using a check-list for assessing economic evaluations (Drummond et al. 2005). Results The literature search yielded 258 titles and abstracts. Out of these, 93 studies were selected and read in full text. There was a vast heterogeneity in study design. No clear evidence was found. Methodology regarding the odontological part was acceptable in a few studies but the methodology for the economic evaluation was insufficient. Conclusions and discussion This review reveals a need for studies with improved quality in economic evaluation in oral health care. We will propose and discuss a model for economic evaluation of diagnostic methods that will contain information of how to (i) identify costs (ii) categorise costs and (iii) value costs. This model will be applied in the SEDENTEXCT project on Cone Beam Computed Tomography. Reference: Drummond MF, Sculpher MJ, Torrance GW, O´Brian BJ, Stoddart GL. Methods for the economic evaluation of health care programmes, Oxford, 2005, Oxford Medical Publications, 3rd ed. The research leading to these results has received funding from the European Atomic Energy Community’s Seventh Framework Programme FP7/2007-2011 under grant agreement no 212246 (SEDENTEXCT: Safety and Efficacy of a New and Emerging Dental X-ray Modality).
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3.
  • Devlin, Hugh, et al. (författare)
  • Automated osteoporosis risk assessment by dentists : a new pathway to diagnosis
  • 2007
  • Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 40:4, s. 835-842
  • Tidskriftsartikel (refereegranskat)abstract
    • 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. PMID: 17188590 [PubMed - indexed for MEDLINE]
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4.
  • Devlin, Hugh, et al. (författare)
  • Diagnosing osteoporosis by using dental panoramic radiographs : the OSTEODENT project
  • 2007
  • Ingår i: Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. - : Elsevier BV. - 1079-2104 .- 1528-395X. ; 104:6, s. 821-828
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: Measurement of cortical thickness and subjective assessment of cortical porosity on panoramic radiographs are methods previously reported for diagnosing osteoporosis. The aims of this study were to determine the relative efficacy of the mandibular cortical index and cortical width in detecting osteoporosis, both alone and in combination, and to determine the optimal cortical width threshold for referral for additional osteoporosis investigation. STUDY DESIGN: Six hundred seventy-one postmenopausal women 45 to 70 years of age were recruited for this study. They received dual energy x-ray absorptiometry (DXA) scans of the left hip and lumbar spine (L1 to L4), and dental panoramic radiographic examinations of the teeth and jaws. Three observers separately assessed the mandibular cortical width and porosity in the mental foramen region of the mandible. Cortical width was corrected for magnification errors. Chi-squared automatic interaction detection analysis (CHAID) software was used (SPSS AnswerTree, version 3.1, SPSS Inc., Chicago, IL). RESULTS: Chi-squared automatic interaction detection analysis showed that the cortical porosity was a poorer predictor of osteoporosis than mandibular cortical width. For the 3 observers, a mandibular cortical width of <3 mm provided diagnostic odds ratios of 6.51, 6.09, and 8.04. The test is therefore only recommended in triage screening of individuals by using radiographs made for purposes other than osteoporosis. CONCLUSION: When evaluating panoramic radiographs, only those patients with the thinnest mandibular cortices (i.e., <3 mm) should be referred for further osteoporosis investigation. PMID: 17428694 [PubMed - in process]
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5.
  • Devlin, Hugh, et al. (författare)
  • The role of the dental surgeon in detecting osteoporosis : the OSTEODENT study
  • 2008
  • Ingår i: British Dental Journal. - : Springer Science and Business Media LLC. - 0007-0610 .- 1476-5373. ; 204:10
  • Tidskriftsartikel (populärvet., debatt m.m.)abstract
    • OBJECTIVE: To determine if thinning (<3 mm width) of the lower cortical border of the mandible on dental panoramic radiographs, as well as other clinical risk factors, may provide a useful diagnostic test for osteoporosis in young postmenopausal women. DESIGN: Six hundred and fifty-two subjects (age range 45-70 years) were involved in this multi-centre, cross-sectional study. SETTING: Patients were recruited from centres in Leuven (Belgium), Athens (Greece), Manchester (UK), and Malmo (Sweden). SUBJECTS AND METHODS: The subject's age, body weight, whether the patient took hormone replacement therapy or had a history of low trauma fracture were used to form a clinical osteoporosis risk assessment (the OSteoporosis Index of RISk or OSIRIS index). Each patient also received a dental panoramic radiographic examination. RESULTS: One hundred and forty subjects had osteoporosis involving at least one of the measurement sites (lumbar spine, femoral neck or total hip). Those with osteoporosis tended to have a low OSIRIS score and a thinned cortical mandibular border. The area under the ROC curve for using both cortical width and OSIRIS to predict osteoporosis was 0.90 (95% CI = 0.87 to 0.92). There was a significant improvement in the diagnostic ability of the combined OSIRIS and cortical width test over both tests applied separately (p <0.001). The cost effectiveness of the cortical width and OSIRIS model was improved by using a high specificity threshold rather than high sensitivity. However, this analysis ignores the costs associated with missed cases of osteoporosis. CONCLUSION: Dentists have a role to play in the detection and referral of patients at high risk of osteoporosis.
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6.
  • Geraets, Wil G, et al. (författare)
  • Osteoporosis and the general dental practitioner : reliability of some digital dental radiological measures
  • 2007
  • Ingår i: Community Dentistry and Oral Epidemiology. - : Wiley. - 0301-5661 .- 1600-0528. ; 35:6, s. 465-471
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: Dental radiographs are relatively inexpensive and are regularly made of a large fraction of the adult population; therefore, they represent an enormous potential as a screening tool for osteoporosis. Monitoring the population by means of dual X-ray absorptiometry (DXA), which is currently the most accepted method for diagnosing osteoporosis, involves enormous costs and facilities. In previous studies, it was shown that the radiographic trabecular pattern shows correlations with the bone mineral density (BMD) as measured by DXA. The objective of this study was to assess the reproducibility of the quantitative analysis of the trabecular pattern on dental radiographs. METHODS: Six regions of interest were selected manually on three digital radiographic images of 20 women. This process was performed 10 times resulting in 1200 image samples. For each image sample 26 parameters were measured. The reliability of the parameters was evaluated by means of Cronbach's alpha. RESULTS: Of the values of Cronbach's alpha 83% is at least 0.9 and 99% is at least 0.8. CONCLUSIONS: The measurements of the parameters used in this study are very reproducible. Therefore, the manual selection of the regions of interest does not introduce large amounts of noise. The imaging parameters potentially offer an accurate tool for the prediction of BMD values. PMID: 18039288 [PubMed - in process]
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7.
  • Geraets, Wil G, et al. (författare)
  • Prediction of bone mineral density with dental radiographs
  • 2007
  • Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 40:5, s. 1217-1221
  • Tidskriftsartikel (refereegranskat)abstract
    • 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. PMID: 17317351 [PubMed - indexed for MEDLINE]
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8.
  • Geraets, Wil GM, et al. (författare)
  • Selecting regions of interest on intraoral radiographs for the prediction of bone mineral density
  • 2008
  • Ingår i: Dento-Maxillo-Facial Radiology. - : Oxford University Press (OUP). - 0250-832X .- 1476-542X. ; 37:7, s. 375-379
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: A previous study showed that the trabecular pattern on dental radiographs correlates with femoral and spinal bone mineral density (BMD). The objective of this study was to determine if the correlation is affected by the size and location of the region of interest (ROI). METHODS: In a European research project on osteoporosis, BMD was measured at the left hip and the lumbar spine of 525 women. From all subjects, intraoral radiographs were made of the premolar region in the upper and lower jaws. Two ROIs were indicated manually on each scanned image. The smallest region involved only trabecular bone and the largest also included parts of the neighbouring teeth. The ROIs were subjected to automatic image analysis, yielding 26 measurements per ROI. Stepwise linear regression was used to predict femoral and spinal BMD. RESULTS: Inner and outer regions predicted BMD equally well. The radiographs of lower and upper jaw also predicted BMD equally well. Combining inner and outer regions did not improve the prediction of femoral and spinal BMD, but combining lower and upper jaws did. CONCLUSIONS: This study shows that it is possible to include parts of neighbouring teeth in the ROI used to assess the trabecular pattern and predict BMD. This simplifies the process of selecting the ROIs because no efforts have to be made to exclude neighbouring teeth. Combining ROIs of lower and upper jaws significantly improves the prediction of BMD.
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9.
  • Gustafsson, Pernilla, et al. (författare)
  • Will image quality influence diagnostic accuracy efficacy when diagnosing osteoporosis by intraoral radiography?
  • 2009
  • Ingår i: Programme and abstract book. ; , s. 67-67
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Introduction In 2003-2005, the OSTEODENT study was performed with the aim of identifying the most valid and effective radiographic index for diagnosis of osteoporosis to be used in oral health care. One of the proposed indices was based on visual assessment of the trabecular pattern in intraoral periapical radiographs. Although strict quality criteria were used, the quality of the intraoral radiographs differed due to film placement and projection errors (Lindh et al 2008). Objectives To investigate if the diagnostic accuracy of visual assessment of the trabecular pattern to diagnose osteoporosis in intraoral radiography increased for images with optimal image quality. Material and methods One hundred intraoral radiographs of the upper and lower premolar regions with optimal image quality were chosen from the original sample of 600 images. The trabecular pattern was assessed by four observers and classified into one of three groups (i) dense homogenous trabecular patter, (ii) heterogeneous trabecular pattern, or (iii) sparse homogenous trabecular pattern. The criterion standard was comprised of osteoporosis as measured by DXA. Sensitivity, specificity, odds ratio, and inter- and intra-observer agreement for the assessment of the 100 images with optimal quality were compared to the values obtained from the assessment of the original sample. Results Sensitivity of images of optimal quality increased in the upper jaw as compared to that of the original sample. The odds ratios of images with optimal image quality were higher for both the upper and the lower jaw. The median intraobserver agreement (weighted Kappa) was also slightly higher for both jaws whilst the median interobserver agreement was comparable for the two samples. Conclusions and discussion Although image quality of intraoral radiography influenced the diagnostic accuracy efficacy in osteoporosis diagnosis to some extent, optimal image quality might not be necessary for the usability of the proposed classification in clinical practice. Reference: Lindh C, Horner K, Jonasson G, Olsson P, Rohlin M, Jacobs R , Karayianni K, van der Stelt P, Adams J, Marjanovic E, Pavitt S, Devlin H. The use of visual assessment of dental radiographs for identifying women at risk of having osteoporosis: the OSTEODENT project. Oral Surg, Oral Med, Oral Pathol, Oral Radiol Endod 2008;106:285- 93
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10.
  • Haas, Brian J., et al. (författare)
  • Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans
  • 2009
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 461:7262, s. 393-398
  • Tidskriftsartikel (refereegranskat)abstract
    • Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement(1). To this day, it affects world agriculture by causing the most destructive disease of potato, the fourth largest food crop and a critical alternative to the major cereal crops for feeding the world's population(1). Current annual worldwide potato crop losses due to late blight are conservatively estimated at $6.7 billion(2). Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars(3,4). Here we report the sequence of the P. infestans genome, which at similar to 240 megabases (Mb) is by far the largest and most complex genome sequenced so far in the chromalveolates. Its expansion results from a proliferation of repetitive DNA accounting for similar to 74% of the genome. Comparison with two other Phytophthora genomes showed rapid turnover and extensive expansion of specific families of secreted disease effector proteins, including many genes that are induced during infection or are predicted to have activities that alter host physiology. These fast-evolving effector genes are localized to highly dynamic and expanded regions of the P. infestans genome. This probably plays a crucial part in the rapid adaptability of the pathogen to host plants and underpins its evolutionary potential.
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11.
  • Horner, Keith, et al. (författare)
  • The mandibular cortex on radiographs as a tool for osteoporosis risk assessment : the OSTEODENT Project
  • 2007
  • Ingår i: Journal of clinical densitometry. - : Elsevier BV. - 1094-6950 .- 1559-0747. ; 10:2, s. 138-146
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of this study was to measure the accuracy of porosity of the mandibular cortex on dental panoramic radiographs (DPRs) in diagnosis of osteoporosis, alone and in combination with a clinical risk index. Six hundred seventy-one women (45-70yr) were recruited in the study, and dual-energy X-ray absorptiometry of the hip and lumbar spine was performed. A clinical index of osteoporosis risk (OSIRIS) and a DPR were obtained for each subject. The cortical appearance on the DPR was classified using the mandibular cortical index (MCI) by 5 observers. receiver operating characteristic (ROC) curve analysis was performed with calculation of area under the ROC curve (AUC) and sensitivity and specificity at various thresholds. Complete data were available for 653 subjects, of whom 21.6% had osteoporosis. The AUC for OSIRIS was 0.838. When used alone as the diagnostic test, MCI AUC for the 5 observers ranged from 0.560 to 0.670, significantly less than OSIRIS. Intraobserver and interobserver repeatability of MCI assessment was inconsistent. We conclude that MCI has limited value for osteoporosis diagnosis, being most appropriate as a method of fortuitous case-finding. PMID: 17449308 [PubMed - in process]
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12.
  • Karayianni, Kety, et al. (författare)
  • 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
  • 2007
  • Ingår i: Bone. - : Elsevier. - 8756-3282 .- 1873-2763. ; 40:1, s. 223-229
  • Tidskriftsartikel (refereegranskat)abstract
    • 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
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13.
  • Lindh, Christina, et al. (författare)
  • A comparison of manual and computer-assessed measurements of mandibular cortical width as predictiors of osteoporsis : the OSTEODENT project
  • 2006
  • Konferensbidrag (refereegranskat)abstract
    • Objective: Manual measurement of mandibular cortical width has been shown to be significantly correlated with bone mineral density (BMD) at the hip,spine and forearm.These latter sites are fracture-prone in post-menopausal osteoporosis. We have developed computer software technology, based on active shape modelling, that will automatically detect the mandibular cortex on panoramic radiographs and then measure its width. We wanted to compare manual measurement of mandibular cortical width with semi-automated constrained fit and automated unconstrained fit methods. Material and Methods:The diagnostic ability of these different methods at detecting osteoporosis of the femoral neck was compared using dual energy X-ray absorptiometry as the “gold standard “at these sites. 671 subjects were recruited and their BMD measured at the femoral neck.143 (21.4%) subjects were osteoporotic, classified as a standardized t-score of <-2.5 at any site. The ability of one observer’s manual measurement of mandibular cortical width to act as a diagnostic test for detecting osteoporosis at the femoral neck was assessed using ROC analysis. The AUC under the ROC curve was = 0.748, (se = 0.027; 95% CI = 0.713 to 0.780). Using a previous training set of 132 DPR images, a point distribution model (PDM) was created of the inferior mandibular cortex. Two experts performed this task independently using a graphical user interface, outlining the inferior mandibular cortex by placing equally spaced points on the computer images between the mental foramen and antegonial region. In the constrained fit, four manually defined reference points were placed on the inferior mandibular surface of the images at the left and right antegonial and mental foramen regions. These points served as starting points for the active shape model and the point distribution model was stretched and positioned to match these points. Results:As a diagnostic test in detecting osteoporosis at the hip, the semi- automated constrained fit produced an AUC of 0.755 (se= 0.026; 95% CI = 0.721 – 0.788). In detecting osteoporosis at the hip, the automated unconstrained fit produced an AUC of 0.739 (se = 0.028; 95% CI = 0.704 to 0.772). There were no significant differences in AUC between the manual, and either the constrained or unconstrained fits (p>0.05).
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14.
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15.
  • Nackaerts, Olivia, et al. (författare)
  • Accuracy and precision of a densitometric tool for jaw bone
  • 2006
  • Ingår i: Dento-Maxillo-Facial Radiology. - : British Institute of Radiology. - 0250-832X .- 1476-542X. ; 35:4, s. 244-248
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: To develop a digital densitometric tool for jaw bone to analyse intraoral radiographs. To assess precision and accuracy for this tool and determine the minimal detection threshold for density changes. METHODS: Bone samples deriving from the premolar region of 47 human mandibles were selected for analysis. The samples were obtained from adult cadavers in the department of anatomy (Faculty of Medicine, KULeuven) with ethical approval. Digital radiography was performed on all bone samples. Direct volumetric measurements served as gold standard density values and allowed determination of accuracy. Dual-energy X-ray absorptiometry (DXA) scans were performed on all specimens. For all radiographs, density in mm Al eq was calculated using custom-made software, Osteop. Precision and intraobserver and interobserver reliability of this method were assessed. The bone specimens were progressively decalcified. At standard time intervals the percentage of decalcification was calculated. At each decalcification step, radiographs were taken and analysed. RESULTS: CV was always lower than 3%, which points to a good precision of the method. Correlation between the density measurements in mm Al eq and the DXA results was 0.9, for the density measurements in mm Al eq and the direct density measurements r was 0.5. The custom-made software was able to detect a change in bone mineralization of 6.6%. CONCLUSIONS: The present method for bone densitometric analysis offers potentials for clinical evaluation of bone density and minute bone density changes in the jaw bone.
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16.
  • Nackaerts, Olivia, et al. (författare)
  • Bone density measurements in intra-oral radiographs.
  • 2007
  • Ingår i: Clinical Oral Investigations. - : Springer Science and Business Media LLC. - 1432-6981 .- 1436-3771. ; 11:3, s. 225-229
  • Tidskriftsartikel (refereegranskat)abstract
    • Oral Imaging Center, Department of Dentistry, Faculty of Medicine, KU Leuven, Kapucijnenvoer 7, 3000, Leuven, Belgium. Jaw bone density measurements are applicable in many clinical situations to assess bone tissue. To be able to implement research findings in clinical reality, tools must be simple and low cost. Intra-oral radiographs including a reference material perform well as a densitometric tool. However, the inclusion of a reference material, usually in the form of a metal wedge, is an additional burden for the dentist. The aim of this study was to evaluate whether a reference step wedge is required for accurate densitometric results. Dual energy X-ray absorptiometry measurements and densitometric measurements on intra-oral radiographs using a custom-made software were performed on bone samples from the premolar region of the mandible. Observer agreement of bone density expressed as grey value was high. The correlation between mandibular bone mineral density and the densitometric values on intra-oral radiographs was substantially higher when the aluminium step wedge was included. The Wilcoxon test revealed no significant difference between the density measurements using nine or three steps of the Al reference wedge. Density determination of grey value and mm Aleq thickness value both have good intra- and inter-observer agreement. However, jaw bone densitometry is far more accurate when including a reference wedge. PMID: 17668257 [PubMed - indexed for MEDLINE]
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17.
  • Nackaerts, Olivia, et al. (författare)
  • Is self-reported alcohol consumption associated with osteoporotic mandibular bone loss in women?
  • 2009
  • Ingår i: European Journal of Oral Sciences. - : Wiley. - 0909-8836 .- 1600-0722. ; 117:1, s. 7-12
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of this study was to determine whether alcohol consumption would predict mandibular bone quality and quantity in a large European female population. In total, 672 middle-aged and elderly women (45-70 yr of age; standard deviation = 6) were recruited in the study. Alcohol consumption was recorded through a self-reported questionnaire. Mandibular cortical width was measured, by five observers, in the mental foramen region on panoramic radiographs. Mandibular bone density, expressed as aluminium thickness, was recorded on intra-oral radiographs. Alcohol consumption was associated with a reduction of mandibular bone density and cortical width. This association was higher in subjects with excessive alcohol consumption, defined in the present study as > 14 units consumed per week. This study showed reduced jaw-bone quality in older individuals and in those with increased alcohol consumption.
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18.
  • Nackaerts, Olivia, et al. (författare)
  • Osteoporosis detection using intraoral densitometry
  • 2008
  • Ingår i: Dento-Maxillo-Facial Radiology. - : British Institute of Radiology. - 0250-832X .- 1476-542X. ; 37:5, s. 282-287
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: To determine the diagnostic accuracy of mandibular and maxillary bone density in detecting osteoporosis using receiver operating characteristic (ROC) analysis. METHODS: 671 women between 45 years and 70 years of age underwent dual energy X-ray absorptiometry (DXA) of the hip and lumbar spine. This was the gold standard for diagnosing osteoporosis. Intraoral radiography of the upper and lower right premolar region was performed, using an aluminium wedge as a densitometric reference. Jaw bone density was determined using dedicated software. Observer differences and ROC curves were analysed. RESULTS: For detecting osteoporosis using jaw bone density, the area under the ROC curve (A(z)) was 0.705. For separate analysis of mandibular and maxillary films, sensitivity varied from 33.9% to 38.7% and specificity from 83.5% to 85.3% when using a threshold of 4.3 mm Al equivalent. CONCLUSIONS: Density of the premolar region reaches a fair diagnostic accuracy, which might improve when including additional factors in the analysis and refining the densitometric tool.
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19.
  • Nicopoulou-Karayianni, Kety, et al. (författare)
  • Tooth loss and osteoporosis : the OSTEODENT Study
  • 2009
  • Ingår i: Journal of Clinical Periodontology. - 0303-6979 .- 1600-051X. ; 36:3, s. 190-197
  • Tidskriftsartikel (refereegranskat)abstract
    • AIM: To determine the cross-sectional association of the osteoporotic status of patients with the number of their teeth, with and without taking into account age and/or smoking. MATERIAL & METHODS: At four centres, the study recruited 665 females aged 45-70 years and the number of teeth was counted for 651 subjects. Bone density was measured at the total hip, femoral neck and lumbar spine. RESULTS: The mean number of teeth in the osteoporotic subjects was 3.3 fewer than normal subjects and 2.1 fewer if those with no teeth were excluded. The association between osteoporosis and having 0, three clusters were identified corresponding to different degrees of tooth loss. The overall effect of osteoporosis was as follows: -1.8 teeth before and after adjusting for smoking, -1.2 teeth after adjusting for age, and -1.1 teeth after adjusting for both age and smoking. CONCLUSIONS: We have established a significant association between osteoporosis and tooth loss after adjusting the effect for age and smoking.
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20.
  • Taguchi, Akira, et al. (författare)
  • Visual assessment of non-eroded thin cortex on panoramic radiographs in identifying women with osteoporosis : Osteoporosis Screening Project in Dentistry (OSPD)
  • 2009
  • Ingår i: Programme and abstract book. ; , s. 65-65
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Introduction The presence of an eroded or thinned cortex of the mandible on panoramic radiographs may be useful in identifying women with osteoporosis. However, little is known as to whether a non-eroded thin cortex predicts osteoporosis. Objective To clarify whether visual assessment of non-eroded thin cortex increases the diagnostic efficacy of identifying women with osteoporosis. Materials and methods Of 60 observers who participated in OSPD (Taguchi et al., Bone, 2008), 41 observers visually assessed non-eroded thin cortex in addition to Klemetti’s index (KI) for 100 panoramic radiographs on the OSPD website via the Internet twice with approximately a two-week interval. The area under the receiver operating characteristics curves (AUROC) in identifying women with osteoporosis by both KI and non-eroded thin cortex was calculated on two occasions; non-eroded thin cortex was included in “class 1 of KI (decreased probability of osteoporosis)” or “class 3 of KI (increased probability of osteoporosis)”. Mean AUROC was compared between these two occasions with paired ttest. Results In the first series of observations, the mean AUROC significantly increased when noneroded thin cortex was considered as a sign of increased probability of osteoporosis (mean +/- SD, 0.68 +/- 0.08 vs. 0.70 +/- 0.07, P=0.011). In the second set of observations, the result was unchanged (0.68 +/- 0.09 vs. 0.71 +/- 0.08, P<0.001). Conclusions and discussion Visual identification of a non-eroded thin cortex on panoramic radiographs may increase the diagnostic efficacy of identifying women with osteoporosis.
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21.
  • Verheij, Johannes GC, et al. (författare)
  • Prediction of osteoporosis with dental radiographs and age
  • 2009
  • Ingår i: Dento-Maxillo-Facial Radiology. - : British Institute of Radiology. - 0250-832X .- 1476-542X. ; 38:7, s. 431-437
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: In this study age and the trabecular pattern present on dental radiographs were used to predict the presence of osteoporosis. The objective was to evaluate the contribution of the trabecular pattern to the prediction. METHODS: In this project, 671 women between 45 and 71 years of age were recruited. Medical history was obtained and dental radiographs were made. Bone mineral density (BMD) was measured at three sites to assess the presence of osteoporosis according to the World Health Organization criteria. The radiographs were subjected to image analysis methods yielding measurements of the trabecular pattern. Thereafter, discriminant analysis was used to predict the presence of osteoporosis by means of the trabecular pattern and age. Sensitivity and specificity of age and the trabecular pattern were compared. Also, it was checked whether the inclusion of the trabecular pattern improved the sensitivity and specificity that were obtained when only age was used as the predictor. RESULTS: The sensitivity and specificity of the trabecular pattern present on dental radiographs were almost equal to those of age. However, combining age with the trabecular pattern increased the sensitivity from 0.71 to 0.75 and the specificity from 0.72 to 0.78; the latter increase was statistically significant. CONCLUSIONS: The trabecular pattern predicts the presence of osteoporosis just as well as age does. When combining the trabecular pattern with age, the sensitivity and specificity increased. Only the latter increase was statistically significant.
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