Observer performance in diagnosing osteoporosis by dental panoramic radiographs: results from the osteoporosis screening project in dentistry (OSPD).

Mandibular cortical erosion detected on dental panoramic radiographs (DPRs) may be useful for identifying women with osteoporosis, but little is known about the variation in diagnostic efficacy of observers worldwide. The purpose of this study was to measure the accuracy in identifying women at risk for osteoporosis in a worldwide group of observers using DPRs. We constructed a website that included background information about osteoporosis screening and instructions regarding the interpretation of mandibular cortical erosion. DPRs of 100 Japanese postmenopausal women aged 50 years or older who had completed skeletal bone mineral measurements by dual energy X-ray absorptiometry were digitized at 300 dpi. These were displayed on the website and used for the evaluation of diagnostic efficacy. Sixty observers aged 25 to 66 years recruited from 16 countries participated in this study. These observers classified cortical erosion into one of three groups (none, mild to moderate, and severe) on the website via the Internet, twice with an approximately 2-week interval. The diagnostic efficacy of the Osteoporosis Self-Assessment Tool (OST), a simple clinical decision rule based on age and weight, was also calculated and compared with that of cortical erosion. The overall mean sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 60 observers in identifying women with osteoporosis by cortical erosion on DPRs were 82.5, 46.2, 46.7, and 84.0%, respectively. Those same values by the OST index were 82.9, 43.1, 43.9, and 82.4%, respectively. The intra-observer agreement in classifying cortical erosion on DPRs was sufficient (weighted kappa values>0.6) in 36 (60%) observers. This was significantly increased in observers who specialized in oral radiology (P<0.05). In the 36 observers with sufficient intra-observer agreement, the overall mean sensitivity, specificity, PPV, and NPV in identifying women with osteoporosis by any cortical erosion were 83.5, 48.7, 48.3, and 85.7%, respectively. The mean PPV and NPV were significantly higher in the 36 observers with sufficient intra-observer agreement than in the 24 observers with insufficient intra-observer agreement. Our results reconfirm the efficacy of cortical erosion findings in identifying postmenopausal women at risk for osteoporosis, among observers with sufficient intra-observer agreement. Information gathered from radiographic examination is at least as useful as that gathered from the OST index.

Follow-up study in a patient with Setleis syndrome.

We report on an 8-year-old Japanese boy with Setleis syndrome. The patient had a very characteristic "coarse" facial appearance, bitemporal "forceps marks," skin aplasia, sparse hair, and skin hypo- and hyperpigmentation. He also had previously undescribed manifestations, including an aberrant hair pattern of the forehead, linear skin lesions on the forehead, short palpebral fissures, a small skin tag on the right cheek, cone-shaped teeth, and pectus carinatum. Dermatoglyphic studies documented aberrant distal palmar creases (simian crease variant), 8 arches, and reduced total finger ridge count. When serial photographs were reviewed, his facial characteristics became more obvious with increasing age.

Circadian rhythms in the incorporation and secretion of 3H-proline by odontoblasts in relation to incremental lines in rat dentin.

Circadian incremental lines are universally found in the dentin of animals. They are believed to be caused by functional changes in odontoblasts over 24 hrs. However, the mechanism of rhythmic dentin formation has not yet been elucidated. In the present study, we investigated whether there is a 24-hour rhythm in the collagen-synthetic and secretory activities of odontoblasts by radioautography with 3H-proline as a tracer. Six different groups of rats were injected with 3H-proline at 0000, 0400, 0800, 1200, 1600, or 2000 after the animals had become acclimated to a 12/12-hour light-dark illumination cycle for 2 wks. One hour after the injection, the maxillary incisors were removed and processed for radioautographic study. The silver grains of 3H-proline were most intense over odontoblasts and predentin during the environmental light period, while the nadir occurred during the dark period. The peak value was approximately two-fold higher than the minimum value. Moreover, in the dentin from rats that had been infused with 3H-proline continuously for 10 days by means of osmotic minipumps, silver grains of 3H-proline were heavily distributed over the dark hematoxylin-stained incremental lines. Thus, we demonstrated that odontoblasts show circadian rhythm with regard to collagen synthesis and secretion. These rhythms in odontoblastic function may be responsible for circadian incremental lines in dentin.

Detection of vascular disease risk in women by panoramic radiography.

Low bone mineral density and rapid bone loss of the skeleton are associated with mortality risk from vascular diseases in post-menopausal women. Panoramic radiographic measurements are considered as indicators of skeletal bone mineral density or bone turnover. We hypothesize that such measurements may be associated with vascular disease risk in post-menopausal women. Associations of mandibular cortical shape and width on panoramic radiographs with skeletal bone mineral density and risk factors related to vascular diseases were investigated in 87 post-menopausal women. Cortical shape was associated with skeletal bone mineral density, low-density lipoprotein cholesterol, apolipoprotein B, resting heart rate, and endothelial dysfunction. Cortical width was associated with skeletal bone mineral density, low-density lipoprotein cholesterol, and apolipoprotein A1. Dentists may be able to refer women with increased risk of vascular diseases, as well as low bone mineral density, to medical professionals for further examination by panoramic findings.

Ontogeny of circadian dentinogenesis in the rat incisor.

Periodic growth increments are found universally in the dentine of animals. The goal here was to determine when and how circadian dentine growth increments develop ontogenetically. A total of 97 rat pups, obtained from 13 mothers of the Wistar strain, were injected with nitrilotriacetato lead at appropriate intervals to chronologically label the dentine. Labelled rat pups were killed 5-50 days after birth. Histological transverse sections of the demineralized dentine were obtained from the maxillary incisors of the pups and stained with haematoxylin. Two types of increments were observed in the circumpulpal dentine. The first type was a deeply stained circadian band which appeared at intervals of about 16-24 microns. The other was a faintly stained, narrow, ultradian increment, at intervals of approx. 6-8 microns. The circadian increments were first detected during the second to third week after birth and were observed consistently afterwards. Before the circadian increments developed, the ultradian increments were predominant. These two rhythms seemed to be independent of each other and sometimes coexisted in one section. Thus, the two types of dentine increments may be due to two independent mechanisms.

Skin sensitization and photosensitization studies of hydrophobically modified hydroxypropyl methylcellulose in guinea pigs.

Skin sensitization and photosensitization tests of hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC), a new cellulose derivative used as a thickener for topical pharmaceuticals, were conducted using guinea pigs. An aqueous dispersion of HM-HPMC (3 w/v %) was applied in the tests. Skin reaction was not observed in any animal in the HM-HPMC-treated group or control group. In the photosensitization test, no skin reaction was found in any animal in the test-preparation group or the control group. It was concluded that HM-HPMC dispersion does not exhibit skin sensitizing or photosensitizing activity under the condition of this test.

Detection of post-menopausal women with low bone mineral density and elevated biochemical markers of bone turnover by panoramic radiographs.

OBJECTIVES: The detection of an eroded mandibular cortex on panoramic radiographs and questionnaire-based screening tools show similar diagnostic efficacies for identifying osteoporosis in post-menopausal women. We evaluated whether both tools also have similar diagnostic performances in identifying women with osteoporosis and elevated biochemical markers of bone turnover who have a high risk of fracture. METHODS: Urinary N-telopeptide cross-links of type I collagen (NTx) (corrected for creatinine) and serum levels of total non-bone-specific alkaline phosphatase (ALP) were measured in 99 post-menopausal women aged 44-70 years (mean +/- standard deviation (SD), 54.6 +/- 5.2 years) who underwent bone mineral density (BMD) assessment and panoramic radiography. BMD was measured at the lumbar spine and femoral neck using dual energy X-ray absorptiometry. The Female Osteoporosis Self-assessment Tool for Asia (FOSTA), which is based on age and weight, was used as the questionnaire-based screening tool. Osteoporosis was defined as a BMD T-score of -2.5 or less at either the lumbar spine or the femoral neck. RESULTS: Urinary NTx and serum ALP were significantly associated with cortical erosion, but not with the FOSTA. The areas under the receiver operating characteristics (ROC) curve for identifying participants with osteoporosis were 0.784 for FOSTA and 0.827 for the detection of cortical erosion, and for identifying participants with osteoporosis and elevated urinary NTx they were 0.700 for FOSTA and 0.807 for the detection of cortical erosion. CONCLUSIONS: Our results suggest that panoramic radiography is superior to questionnaire-based screening for identifying women who are at high risk of fracture.

A computer-aided diagnosis system to screen for osteoporosis using dental panoramic radiographs.

OBJECTIVES: An eroded inferior cortex of the mandible detected on dental panoramic radiographs is useful for identifying post-menopausal women with low skeletal bone mineral density (BMD) or osteoporosis. The purposes of this study were to develop a computer-aided diagnosis (CAD) system that automatically determines cortical erosion of the mandible on dental panoramic radiographs and to assess the validation of this CAD system. METHODS: A CAD system was developed based on mathematical morphology for identifying post-menopausal women with low skeletal BMD or osteoporosis, based on World Health Organization criteria, by identifying whether the endosteal margin of mandibular cortical bone was eroded. The sensitivity, specificity, predictive value, accuracy and likelihood for a positive risk result were calculated using dichotomous 2 x 2 tables using 100 panoramic radiographs. RESULTS: For identifying women with low skeletal BMD, the sensitivity and specificity were 76.8% and 61.1%, respectively, the positive and negative predictive values were 90.0% and 36.7%, accuracy was 74.0% and the likelihood for positive risk was 1.96. The respective values for identifying women with osteoporosis were 94.4% and 43.8%, the positive and negative predictive values were 48.6% and 93.3%, respectively, the accuracy was 62.0% and the likelihood for positive risk was 1.68. CONCLUSION: Our results suggest that a CAD system applied to dental panoramic radiographs may be useful for identifying post-menopausal women with low skeletal BMD or osteoporosis.

Diagnostic efficacy of alveolar bone loss of the mandible for identifying postmenopausal women with femoral osteoporosis.

OBJECTIVES: Mandibular cortical width (MCW) detected on panoramic radiographs may be useful for identifying postmenopausal women with osteoporosis. There is little known regarding whether alveolar bone loss (ABL) of the mandible detected on panoramic radiographs is a potentially accurate screening tool for osteoporosis in comparison with MCW. The purpose of this study was to evaluate whether ABL of the mandible on panoramic radiographs is useful for identifying femoral osteoporosis in postmenopausal women in comparison with MCW. METHODS: Three hundred and fifty-four Japanese postmenopausal women (mean age+/-SD, 56.8+/-7.7 years) were recruited for this study. Femoral BMD was measured by dual energy X-ray absorptiometry. Panoramic radiographs were obtained to estimate ABL of the mandible and MCW. RESULTS: A multiple regression analysis revealed that femoral BMD was significantly associated with MCW (P<0.001), weight (P<0.001), age (P<0.001) and ABL of the mandible (P=0.029; adjusted r(2)=0.380). The area under the ROC curve (AUC) for identifying femoral osteoporosis was 0.609 [95% confidence interval (CI), 0.523-0.696] for ABL of the mandible and 0.779 (95% CI, 0.713-0.844) for MCW, respectively. AUC for ABL of the mandible indicated less accuracy. CONCLUSIONS: Our results suggest that ABL of the mandible on panoramic radiographs may not be useful for identifying postmenopausal women with femoral osteoporosis in comparison with MCW.

Risk of vertebral osteoporosis in post-menopausal women with alterations of the mandible.

BACKGROUND: Previous studies have suggested that a thin or eroded cortex of the mandible detected on dental panoramic radiographs is associated with low vertebral bone mineral density (BMD) or osteoporosis. However, those studies did not estimate the multivariate-adjusted risk for low vertebral BMD or osteoporosis associated with alterations of the mandible. METHODS: BMD of the lumbar vertebrae (L2-L4) was compared among quartiles of cortical width and among three cortical shape categories in 450 post-menopausal women (mean age, 57.2 years), adjusted for potential confounders. The odds ratios for low BMD or osteoporosis according to cortical width and shape were also calculated. RESULTS: Significant associations were found between cortical width and shape, and vertebral BMD. The odds ratios for low vertebral BMD associated with the second, third and lowermost quartiles of cortical width were 1.71 (95% confidence interval (CI), 0.96-3.05), 2.30 (95% CI, 1.29-4.11) and 5.43 (95% CI, 2.16-10.71), respectively, compared with the uppermost quartile. The odds ratios for osteoporosis according to cortical width category were similar to those for low BMD. The odds ratios for low BMD associated with mildly to moderately and severely eroded cortices were 3.85 (95% CI, 2.37-6.25) and 7.84 (95% CI, 2.57-23.90), respectively, compared with normal cortex. The odds ratios for osteoporosis associated with mildly to moderately and severely eroded cortices were 4.73 (95% CI, 2.54-8.80) and 14.73 (95% CI, 6.14-35.47), respectively. CONCLUSIONS: Post-menopausal women with alterations of the mandible may have an increased risk for low vertebral BMD or osteoporosis.

Identification of post-menopausal women at risk of osteoporosis by trained general dental practitioners using panoramic radiographs.

BACKGROUND: An eroded inferior cortex of the mandible on panoramic radiographs may be useful for identifying post-menopausal women with low bone mineral density (BMD), or osteoporosis. The purpose of this study was to assess whether trained general dental practitioners (GDPs) can identify post-menopausal women with undetected low skeletal BMD as well as spinal fractures by panoramic radiographs in their clinics. METHODS: Out of 455 women aged 50 years and older who visited the dental clinics of 22 trained GDPs and had panoramic radiographic assessment for the examination of dental diseases between June and December 2004, 168 post-menopausal women were diagnosed as having low skeletal BMD based on cortical erosion findings. Of these women, 39 women aged 50-84 years (mean age (SD, standard deviation), 64.8 (7.4) years) with no previous diagnosis of osteoporosis participated in this study. BMD at the lumbar spine and femoral neck was measured using dual energy X-ray absorptiometry (DXA). Spine fractures were assessed on lateral radiographs obtained at the time of the DXA assessment. RESULTS: Two women (5.1%) had normal BMD (BMD T-score>-1.0), 21 women (53.9%) had osteopenia (BMD T-score of -2.5 to -1.0) and 16 women (41.0%) had osteoporosis (BMD T-score<-2.5). Eight women (20.5%) had fractures at the thoracic spine, lumbar spine, or both. CONCLUSIONS: Our results suggest that a high percentage of post-menopausal women with undetected low skeletal BMD as well as spinal fractures may be identified based on trained GDPs' analyses of their panoramic radiographs.

Computer-aided system for measuring the mandibular cortical width on dental panoramic radiographs in identifying postmenopausal women with low bone mineral density.

INTRODUCTION: Mandibular inferior cortical width manually measured on dental panoramic radiographs may be useful for identifying postmenopausal women with low skeletal bone mineral density (BMD). Automatic measurement of cortical width may enable us to identify a large number of postmenopausal women with suspected low skeletal BMD. The purposes of this study were to develop a computer-aided system for measuring mandibular cortical width on dental panoramic radiographs and clarify the diagnostic efficacy of this system. METHODS: Panoramic radiographs of 100 postmenopausal women who had had BMD assessments of the lumbar spine and the femoral neck were used in this study. Experienced oral radiologist determined the position of the mental foramen on 100 digitized dental panoramic radiographs. After determination of the mental foramen, mandibular cortical width below the mental foramen was measured automatically with a computer-aided system by identifying the area of interest, enhancing the original image, determining inner and outer margins of the cortex, and selecting an appropriate point. Cortical width measured by this system was compared with BMD of the lumbar spine and the femoral neck. RESULTS: There were statistically significant correlation between cortical width measured by the computer-aided system and spinal BMD (r=0.50) and femoral neck BMD (r=0.54). These correlations were similar with those between cortical width by manual measurement and skeletal BMD. Sensitivity and specificity for identifying postmenopausal women with low spinal BMD by the computer-aided system were about 88.0% and about 58.7%, respectively. Those for identifying postmenopausal women with low femoral neck BMD by this system were about 87.5% and about 56.3%, respectively. CONCLUSION: Our results suggest that our computer-aided system may be useful for identifying postmenopausal women with low skeletal BMD.

Diagnostic performance of general dental practitioners after lecture in identifying post-menopausal women with low bone mineral density by panoramic radiographs.

OBJECTIVES: Mandibular cortical erosion detected on panoramic radiographs may be useful for identifying post-menopausal women with low skeletal bone mineral density (BMD). The purposes of this study were to calculate the diagnostic performance of general dental practitioners (GDPs) who attended a lecture on identifying post-menopausal women with low BMD from findings on panoramic radiographs and to evaluate the influence of GDPs' age on diagnostic performance. METHODS: After a 1 h lecture, 111 GDPs were asked to classify the mandibular cortex (normal or eroded) on panoramic radiographs obtained from 100 post-menopausal women who have had skeletal BMD assessment. Low BMD was defined as a BMD T score of -1.0 or less. Diagnostic performance was analysed by comparing two groups classified by mandibular cortex (women with normal cortex and women with any eroded cortex) with those classified by BMD (women with normal BMD and women with low BMD). RESULTS: The mean sensitivity, specificity, positive predictive value, negative predictive value, accuracy and likelihood ratio for a positive risk result were 73.0% (95% confidence interval [CI]; 71.3 to 74.7%), 49.0% (95% CI; 46.4 to 51.5%), 66.9% (95% CI; 66.0 to 67.8%), 57.0% (95% CI; 55.8 to 58.2%), 62.9% (95% CI; 62.1 to 63.7%) and 1.51 (95% CI; 1.44 to 1.58), respectively. GDPs' age did not influence diagnostic performance. CONCLUSIONS: Our results suggest that 73.0% of women who had low skeletal BMD can be identified by GDPs after a lecture on the use of panoramic radiographs as an aid in diagnosing low BMD; however, the diagnostic performance may not be influenced by GDPs' age.

Relationship between bone mineral density and tooth loss in elderly Japanese women.

OBJECTIVE: To evaluate the relationship between vertebral bone mass and tooth loss and jaw bone mass in elderly Japanese women. METHODS: Mandibular cortical bone mass, alveolar bone height and number of teeth present (total, anterior, and posterior) were compared with the 3rd lumbar vertebral bone mineral density (L3BMD), measured by dual energy computed tomography (DEQCT), in 90 Japanese women by means of multiple regression analysis, controlling for body mass index, menopausal status, years since menopause and self-reported periodontal condition. RESULTS: Mandibular cortical bone mass and number of posterior teeth were associated with both alveolar bone height and L3BMD, but there was no association between alveolar bone height, number of anterior teeth present and L3BMD. CONCLUSION: Our results suggest that the loss of posterior teeth may be associated with a decrease not only in alveolar bone height, but also alveolar bone mineral density (BMD). The latter may be related to a decrease of lumbar vertebral BMD.

Possible mechanism of gene transfer into early to mid-gestational mouse fetuses by tail vein injection.

Our aim is to develop a simple gene transfer method into egg cylinder and mid-gestational murine embryos. We examined whether plasmid/lipid complexes injected into the tail veins of pregnant transgenic mice can be transferred to fetuses at E 4.5-13.5. When pregnant CETZ-17 mice carrying a transgene consisting of a ubiquitous promoter, floxed EGFP/CAT and the LacZ gene, were injected with a Cre expression vector DNA/lipid complex, Cre-mediated excision of the transgenes, as evaluated by X-gal staining, occurred in 10-50% of fetuses treated at E 11.5-13.5. Although younger embryos remained unstained, PCR analysis revealed low levels of the Cre vector DNA and recombined transgene. To examine the fate of a solution given intravenously, we injected trypan blue or fluorescence-labeled plasmid DNA/lipid complexes into females at E 5.5-11.5 and E 6.5, respectively. Both collected in the visceral endoderm (VE) lineage, but were undetectable in the embryo proper. These findings suggest that substances in maternal blood are delivered to post-implantation embryos via cells of the VE lineage and placenta, but that most are trapped in the VE. If significantly improved, gene transfer to fetuses by injection into the maternal circulation may become a promising tool in fetal gene therapy and embryological studies.

Usefulness of panoramic radiography in the diagnosis of postmenopausal osteoporosis in women. Width and morphology of inferior cortex of the mandible.

OBJECTIVES: To evaluate the usefulness of width and morphology of the inferior cortex of the mandible on panoramic radiographs in the diagnosis of postmenopausal osteoporosis. METHODS: The width and morphology of the mandibular inferior cortex on panoramic radiographs were compared with trabecular bone mineral density (TBMD) of the 3rd lumbar vertebrae (L3) measured by dual energy quantitative computed tomography in 29 premenopausal and 95 postmenopausal women. RESULTS: There was a significant negative correlation between the width (Kendall's tau = -0.36, p < 0.001) and morphology (Kendall's tau = -0.49, p < 0.001) of the mandibular inferior cortex and the L3 TBMD. Regression analysis showed that significant linear relationships were observed between the L3 TBMD and age (p < 0.001), cortical width (p < 0.05), morphology (p < 0.05), controlling body mass index, number of teeth present and menopausal status (R2 = 0.42). CONCLUSION: Our results suggest that panoramic radiography could be reliable in screening for osteoporosis.