Evaluation of the non-functional tooth contact in patients with temporomandibular disorders by using newly developed electronic system.

The aims of this study were to introduce a novel electronic system for reliable evaluation of the non-functional tooth contact in patients with temporomandibular disorders (TMDs) and investigate the possible associations between the non-functional tooth contact and some characteristics of the patients with TMD. We designed and installed a software program to send emails regarding the non-functional tooth contact to the subjects' preregistered cellular phones at intervals of 20 ± 9 min daily for 10 consecutive days. Twelve patients with TMD and 12 gender- and age-matched healthy subjects responded via emails to one of 3 choices: no tooth contact, tooth contact during oral functions or tooth contact not associated with oral functions. The influence of subjective stress, anxiety, depression, personality and daily activities on tooth contact was then assessed. The frequency of the non-functional tooth contact was significantly higher in the patients with TMD than in the healthy subjects (35·0% vs. 9·6%, P < 0·001), while no significant group difference was found for the frequency of functional tooth contact, the stress, anxiety, depression and personality.

Establishment of mesenchymal cell line derived from human developing odontoma.

OBJECTIVES: An odontoma, which shows proliferating odontogenic epithelium and mesenchymal tissue, is one of the most common odontogenic tumors encountered. These are commonly found in tooth-bearing regions, although the etiology remains unknown. There are no previous reports of an established line of immortalized human odontoma cells. METHODS: Using odontoma fragments obtained from a girl treated at our department, we established an immortalized human odontoma cell line and investigated cell morphology, dynamic proliferation, the presence of contamination, and karyotype. Moreover, cell characterization was examined using osteogenic and odontogenic markers. RESULTS: We successfully established a mesenchymal odontoma cell (mOd cells). The cells were found to be fibroblastic and had a high level of telomerase activity. Cell growth was confirmed after more than 200 population doublings without significant growth retardation. mOd cells expressed mRNA for differentiation markers, including collagen type I (COLI), alkaline phosphatase, bone sialoprotein, osteopontin, osteocalcin, cementum-derived protein (CP-23), dentin sialophosphoprotein (DSPP), and distal-less homeobox 3 (DLX3), as well as bone morphogenetic proteins (BMPs). In addition, they showed a high level of calcified nodule formation activity in vitro. CONCLUSIONS: We successfully established a cell line that may be useful for investigating the mechanisms of normal odontogenesis as well as characteristics of odontoma tumors.

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.

Electroencephalogram measurement from the hairy part of the scalp using polymer-based dry microneedle electrodes.

This paper reports a successful electroencephalogram (EEG) measurement from the hairy part of the scalp using a polymer-based dry microneedle electrode. The electrode consists of 25 pillars, each of which has a sharp microneedle on the top. Hairs are collected into the gaps of the pillars and the microneedles can reach the scalp surface. Since the microneedles can penetrate through the stratum corneum, no conductive gel is necessary to acquire high quality EEG. We experimentally investigated the pillar diameters in EEG measurement from the occipital region with hairs. The fabricated electrodes successfully measured EEG without any skin preparation or conductive gel.

Establishment of human cementifying fibroma cell lines by transfection with temperature-sensitive simian virus-40 T-antigen gene and hTERT gene.

Human cementifying fibroma (HCF) is a benign fibro-osseous neoplasm of periodontal ligament (PDL) origin containing varying amounts of mineralized material resembling cementum. In the present study, we established cell lines from HCF, which were detected in the mandible of a 54-year-old Japanese man. To obtain immortalized cell clones, we undertook transfection with temperature-sensitive simian virus-40 (SV40) T-antigen and hTERT into HCF cells. Cells transfected with SV40 T-antigen entered "crisis" state between passages 22 and 35, but activation of telomerase by transfection with hTERT in the SV40-transformed HCF cells resulted in bypass of the crisis and maintenance over passage 200. HCF cell lines decreased the expression of SV40 T-antigen and the activity of cell proliferation at a nonpermissive temperature (39 degrees C) in comparison with that at a permissive temperature (33 degrees C). High activities of alkaline phosphatase and mineralization and the expression of type I collagen, osteocalcin, osteopontin, and bone sialoprotein by reverse transcription-polymerase chain reaction (RT-PCR) were observed in HCF cells at 39 degrees C. Overall, these findings suggest that: (i) HCF cell lines may represent a novel in vitro human cell model for the study of the regulatory mechanism of differentiation and proliferation of the human PDL; and (ii) transfection of plasmids encoding the temperature-sensitive SV40 T-antigen gene and hTERT gene may be useful for obtaining immortalized cell lines from benign human tumor and, probably, nonneoplastic human tissues.

Immunohistochemical demonstration of an enamel sheath protein, sheathlin, in odontogenic tumors.

Enamel proteins can be useful markers for assessment of the functional differentiation of neoplastic epithelium and the nature of extracellular matrices in odontogenic tumors. In the present study, we examined immunohistochemical localization of sheathlin, a recently cloned enamel sheath protein, in various odontogenic tumors to evaluate functional differentiation of tumor cells and the nature of hyalinous or calcified matrices in odontogenic neoplasms. Distinct immunolocalization of sheathlin was observed in the immature enamel of the tooth germ at the late bell stage. Secretory ameloblasts facing the enamel matrix also showed positive staining in their cytoplasm. Definite localization of sheathlin was demonstrated in the enamel matrix in odontogenic tumors with inductive dental hard tissue formation such as ameloblastic fibroodontomas and odontomas. Immunoexpression of sheathlin was, furthermore, demonstrated in eosinophilic droplets in solid nests of adenomatoid odontogenic tumor (AOT) and ghost cells in the epithelial lining of calcifying odontogenic cyst (COC). In AOT, cells facing the eosinophilic droplets also expressed the protein in their cytoplasm. There was neither intracellular staining for sheathlin in the tumor cells nor extracellular staining in the matrix of ameloblastomas and calcifying epithelial odontogenic tumors. Dentin, dysplastic dentin-like hyaline material and cementum in the tumors examined were negative for sheathlin. These results show that immunodetection of sheathlin is a useful marker for functional differentiation of secretory ameloblasts and enamel matrix, which is often hard to differentiate from other hard tissues in odontogenic tumors. Our findings from the view point of sheathlin expression support that the tumor cells of ameloblastomas do not attain full differentiation into functional ameloblasts. It is very interesting that epithelial cells in odontogenic tumors can differentiate into functional ameloblasts without induction by odontogenic mesenchyme, as shown by immunoexpression of sheathlin in eosinophilic droplets within solid epithelial sheets in AOT and ghost cells in the epithelial lining of COC where inductive participation of mesenchymal cells was most unlikely.

Peripheral ameloblastoma: biological profile based on 160 cases from the literature.

The present profile of the peripheral ameloblastoma (PA) is based on a literature survey of 160 published tumour cases. The PA is an exophytic growth localized to the soft tissues overlying the tooth-bearing areas of the jaws, the initial diagnosis often being fibrous epulis. In most cases there is no radiological evidence of bone involvement, but a superficial bone erosion--known as cupping or saucerization--may be detected at operation. The PA accounts for 2-10% of all ameloblastomas. The overall average age is 52.1 years, slightly higher for males (52.9 years) than for females (50.6 years). Thus, the PA occurs at a significantly higher age than the intraosseous ameloblastoma (IA; 37.4 years). The male/female ratio amounts to 1.9:1, as opposed to 1.2:1 for the IA. The male/female ratio for the Japanese cases included in this survey is 2.5:1 as opposed to that of non-Japanese cases 1.4:1. As to the location of PA, the maxilla/mandible ratio is 1:2.6. The mandibular premolar region accounts for 32.6% of all sites. Five extra-gingival lesions have been reported under the term PA. As these cases most likely represent salivary gland tumours, they are not accepted under the diagnosis of PA. The odontogenic gingival epithelial hamartoma shows clinical, histological and behavioural features almost identical to the PA, and it is discussed whether this lesion and the PA should be considered one and the same entity. Pathogenetically, two major sources are discussed: remnants of the dental lamina and the oral surface epithelium. Histologically, the PA consists of proliferating odontogenic epithelium exhibiting the same histomorphological cell types and patterns as seen in the IA. The stroma is that of a mature, fibrous connective tissue. The indolent biological behaviour dictates a conservative therapeutical approach. It is discussed whether PA is a true neoplastic counterpart of the IA or rather an odontogenic hamartomatous lesion. Six cases of malignant PA have been reported.

Clinical and histopathological analyses of desmoplastic ameloblastoma.

Desmoplastic ameloblastoma (DA) is an unusual subtype of ameloblastoma characterized by pronounced desmoplastic stroma. There is, however, still argument whether DA is a distinct clinicopathologic entity. To enhance knowledge of DA, 7 cases of DA (7.9%) were retrieved from 89 ameloblastomas field in the Department of Oral Pathology, Hiroshima University School of Dentistry and analyzed clinicopathologically and histopathologically. The mean age of the patients with DA and non-DA at the time of the diagnosis was 40.6 +/- 5.9 years and 33.1 +/- 2.0 years, respectively. The male-to-female ratio was 2.5:1 in DA and 1.8:1 in non-DA. Four (57%) DAs were located in the maxilla where only 6% of the non-DA occurred. Interestingly, all DAs arose in the anterior/premolar area of the jaws and 6 cases were located mainly within the alveolus. None of the DA showed typical radiographic features of ameloblastoma. In 5 DAs, scattered radiopacities were observed in the radiolucent lesion and gave preoperative diagnoses of non-ameloblastomatous lesions or even osteosarcoma. All DAs showed pronounced desmoplastic stroma where there were compressed tumor islands usually lacking a peripheral layer of ameloblastic cells and a central zone of stellate reticulum. There was cystic change within the epithelial nests in 3 DAs and true glandular structures with mucus cells in a case of DA. Tumor islands often infiltrated into marrow spaces of surrounding bone. There was no capsule formation. Recurrence rate was 14% in DA and 20% in non-DA. The present study based on data of DA in the Japanese population supports that DA must be considered as a distinct clinicopathologic entity.

Immuno-localization of COX-1 and COX-2 in the rat molar periodontal tissue after topical application of lipopolysaccharide.

Up-regulation of prostaglandin E2 (PGE2) production in the periodontal tissue is considered to be important for periodontal tissue destruction. The purpose of the study was to demonstrate the dynamic changes of immuno-localization of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in rat periodontal tissue after topical application of lipopolysaccharide (LPS: 5 mg/ml in physiological saline) from Escherichia coli into the rat molar gingival sulcus. In the normal periodontal tissue, small numbers of junctional epithelium (JE) cells and numerous osteocytes embedded in alveolar bone constitutively expressed COX-1. The COX-1 expression was not effected by LPS application. JE cells, especially in the coronal portion of JE also expressed COX-2. LPS application induced the JE cells with consequent transient expression of COX-2 with a peak at day 1. These findings suggest that JE cells may play a critical role in first defense line against LPS challenge and PGE2 from JE cells may be responsible for the initiation of periodontal inflammation. In the deep periodontal tissue, cementoblasts and osteoblasts showed constitutive expression of COX-2, which may be induced by continuous cyclic tension force due to occlusal pressure. LPS application caused a transient up-regulation of COX-2 expression in periodontal ligament fibroblasts, cementoblasts and osteoblasts. It is suggested that the inducible production of PGE2 via COX-2 by these cells may be associated with connective tissue destruction and alveolar bone resorption.

[A case of acute idiopathic pandysautonomia].

A 19-year-old male student who complained of orthostatic syncope and low grade fever was admitted to our hospital and diagnosed acute idiopathic pandysautonomia (AIPD). He had dysesthesia and hypalgesia of his face and the upper part of the level of Th4, slight hypalgesia of the limbs and slightly exaggerated jaw jerk and diminished deep tendon reflexes of the limbs, but his main clinical manifestations were orthostatic hypotension (OH), sweating disturbance and alternative diarrhea and constipation. Paroxysmal cough and vomiting attack, severe weight loss and slight emotional change were also observed. There were no abnormal findings in the routine laboratory examinations, but the protein in the cerebrospinal fluid was slightly elevated in the initial state. The results of autonomic function tests, such as OH on tilting, no blood pressure effects on cold pressor test and hand grip test, no overshoot in Valsalva maneuver, low norepinephrine (NE) level at resting and poor NE response on tilting, exaggerated response to a small dose of NE infusion (denervation supersensitivity), suggested that the sympathetic post-ganglionic sites were chiefly affected. The parasympathetic nervous functions were seemed to be almost intact by the results of Aschner test, Czermak test and coefficient variation of R-R intervals. Sural nerve biopsy revealed a marked loss of small myelinated and unmyelinated fibers, suggesting axonal degeneration. These findings were different from those of the Guillain-Barré syndrome (GBS), although the allergic or immunological mechanisms are suggested as the cause of both AIPD and GBS. In this case, amezinium metilsulfate, an indirect sympathomimetic agent, was most effective to OH and cough attack.

[Age estimation from tooth attritions of lower incisors--discussion on the "Amano's method"].

As a method of age estimation from teeth we focused our attention on attritions of lower incisors. Using the Amano's method, we took records of tooth attritions in the planted state of 83 subjects whose ages ranged from 14 to 76 years. A positive correlationship was found to exist between the tooth attrition index and the actual age, allowing to establish the following formula which graphically shows a straight line: Y = 8.505X + 26.073 (r = 0.607), where X is the mean of attrition indexes of lower incisors and Y, the estimated age. In our method of age estimation through attrition indexes, we took advantage of probability and confidence interval. In addition, our method was contrasted with Amano's method, a widely used one in Japan.

Aberrant beta-catenin expression and adenomatous polyposis coli gene mutation in ameloblastoma and odontogenic carcinoma.

The Wnt pathway is involved in carcinogenesis and three regulatory genes of the Wnt pathway, APC (adenomatous polyposis coli), beta-catenin and Axin are frequently mutated in some primary human cancers. This study was conducted to clarify the relation of beta-catenin accumulation and the mutation of the CTNNB1 (beta-catenin) gene with the mutation of APC gene in the process of development of odontogenic tumors including ameloblastoma and odontogenic carcinoma (OC). beta-Catenin accumulation was examined by immunohistochemistry in formalin-fixed, paraffin-embedded samples of six ameloblastomas and eight OCs. We also performed a mutation analysis of CTNNB1 and APC to examine the cause of beta-catenin accumulation. All ameloblastoma cases and six out of eight (75%) OC cases exhibited beta-catenin accumulation in the nucleus. CTNNB1 mutation was only found in one OC case, whereas three of six (50%) ameloblastoma cases and two out of eight (25%) OC cases had APC mutations within the mutational cluster region. Our findings suggest that aberrant beta-catenin expression and APC missense mutation may play an important role for the pathogenesis of epithelial odontogenic tumors.

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.

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.

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.

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.

Migration of formaldehyde and acetaldehyde into mineral water in polyethylene terephthalate (PET) bottles.

The levels of formaldehyde (FA) and acetaldehyde (AA) in polyethylene terephthalate (PET) bottles and in commercial mineral water are reported. All the water samples bottled in Japan contained detectable levels of FA (10.1-27.9 microg l(-1)) and AA (44.3-107.8 microg l(-1)). Of 11 European bottled water samples, eight did not contain either FA or AA, while the remaining three had detectable levels of FA (7.4-13.7 microg l(-1)) and AA (35.9-46.9 microg l(-1)). In three North American bottled water samples, two contained FA (13.6 and 19.5 microg l(-1)) and AA (41.4 and 44.8 microg l(-1)), and one did not. Regardless of the region of origin, all the sterilized water samples contained FA and AA, whilst in contrast, none of the unsterilized water without carbonate contained FA or AA. Of the carbonated water samples, three contained FA and AA, and one did not. When fortified with FA and AA, the commercial water sample without otherwise detectable FA and AA was able to reduce levels, although the commercial water sample containing FA and AA could not. The presence of bacteria in the commercial water samples was investigated using an ATP-based bioluminescent assay and heterotrophic plate count method. The commercial water without FA and AA contained heterotrophic bacteria, whilst the commercial water with FA and AA did not contain detectable bacteria. It is suggested that in this case both FA and AA migrated from PET materials, but were subsequently decomposed by the heterotrophic bacteria in the unsterilized water.