| 1. |
- Allen, P Danny, et al.
(författare)
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Detecting reduced bone mineral density from dental radiographs using statistical shape models
- 2007
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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
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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. |
- Devlin, Hugh, et al.
(författare)
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Automated osteoporosis risk assessment by dentists : a new pathway to diagnosis
- 2007
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Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 40:4, s. 835-842
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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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| 3. |
- Geraets, Wil G, et al.
(författare)
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Osteoporosis and the general dental practitioner : reliability of some digital dental radiological measures
- 2007
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Ingår i: Community Dentistry and Oral Epidemiology. - : Wiley. - 0301-5661 .- 1600-0528. ; 35:6, s. 465-471
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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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| 4. |
- Geraets, Wil G, et al.
(författare)
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Prediction of bone mineral density with dental radiographs
- 2007
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Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 40:5, s. 1217-1221
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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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| 5. |
- Horner, Keith, et al.
(författare)
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The mandibular cortex on radiographs as a tool for osteoporosis risk assessment : the OSTEODENT Project
- 2007
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Ingår i: Journal of clinical densitometry. - : Elsevier BV. - 1094-6950 .- 1559-0747. ; 10:2, s. 138-146
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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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| 6. |
- Horner, Keith, et al.
(författare)
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The relationship between the OSTEODENT index and hip fracture risk assessment using FRAX
- 2010
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Ingår i: Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. - : Elsevier BV. - 1079-2104 .- 1528-395X. ; 110:2, s. 243-249
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The OSTEODENT index is a predicted probability of osteoporosis derived from a combination of an automated analysis of a dental panoramic radiograph and clinical information. This index has been proposed as a suitable case-finding tool for identification of subjects with osteoporosis in primary dental care; however, no data exist on the relationship between OSTEODENT index and fracture risk. The aims of this study were to assess the relationship between the OSTEODENT index and hip fracture risk as determined by FRAX and to compare the performance of the OSTEODENT index and FRAX (without femoral BMD data), in determining the need for intervention as recommended in UK national treatment guidance. STUDY DESIGN: The study was a retrospective analysis of data from 339 female subjects (mean age 55.3 years), from 2 centers: Manchester (UK) and Leuven (Belgium). Clinical information and femoral neck BMD were available for FRAX, and dental panoramic radiographic data and clinical information were available to calculate the OSTEODENT index. Subjects were classified into "treat" or "lifestyle advice and reassurance" categories using the National Osteoporosis Guideline Group (NOGG) threshold. RESULTS: The OSTEODENT index result was significantly related to the 10-year probability of hip fracture derived from the reference standard FRAX tool (Rs = 0.67, P < .0001); 84 patients (24.8%) were allocated to the "treat" category on the basis of FRAX and the UK national guidance. Using this "treatment/no treatment" classification as the reference standard, ROC analysis showed no significant difference between areas under the curves for the OSTEODENT index (0.815) and the 10-year probability of hip fracture derived from the FRAX index without BMD (0.825) when used as tests for determining therapeutic intervention. CONCLUSION: The results suggest that the OSTEODENT index has value in prediction of hip fracture risk. Prospective trials are needed to confirm this finding and to examine the feasibility for its use in primary dental care.
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| 7. |
- Karayianni, Kety, et al.
(författare)
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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
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Ingår i: Bone. - : Elsevier. - 8756-3282 .- 1873-2763. ; 40:1, s. 223-229
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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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| 8. |
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| 9. |
- Nackaerts, Olivia, et al.
(författare)
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Accuracy and precision of a densitometric tool for jaw bone
- 2006
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Ingår i: Dento-Maxillo-Facial Radiology. - : British Institute of Radiology. - 0250-832X .- 1476-542X. ; 35:4, s. 244-248
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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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| 10. |
- Nackaerts, Olivia, et al.
(författare)
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Bone density measurements in intra-oral radiographs.
- 2007
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Ingår i: Clinical Oral Investigations. - : Springer Science and Business Media LLC. - 1432-6981 .- 1436-3771. ; 11:3, s. 225-229
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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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