| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Oral and Maxillofacial Radiology, Hiroshima University Hospital,
1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
2 Department of Obstetrics and Gynecology, Division of Clinical Medical Science,
Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima,
Japan.
3 Department of Oral and Maxillofacial Radiology, Division of Medical
Intelligence and Informatics, Graduate School of Biomedical Sciences,
Hiroshima University, Hiroshima, Japan.
Received March 8, 2004;
accepted after revision May 11, 2004.
Supported by a grant-in-aid for scientific research by the Japan Society
for the Promotion of Science (grant no. 14571786).
Abstract
 Top Abstract IntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
SUBJECTS AND METHODS. We calculated the diagnostic performances of panoramic measurements and the OST for identifying women with spinal osteoporosis in both 159 healthy postmenopausal and 157 postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use. Spinal osteoporosis was defined as a bone mineral density T score of –2.5 or less at the lumbar spine. Cortical shape and width were evaluated on dental panoramic radiographs. Receiver operating characteristic curve analyses were used to determine the optimal cutoff thresholds for cortical width and the OST in healthy postmenopausal women.
RESULTS. The sensitivity and specificity, respectively, for identifying women with spinal osteoporosis were 89.5% and 33.9% for cortical width, 86.8% and 57.8% for the OST, and 86.8% and 63.6% for cortical shape in healthy postmenopausal women. Sensitivity and specificity, respectively, were 92.5% and 35.0% for cortical width, 72.5% and 58.1% for the OST, and 80.0% and 64.1% for cortical shape in postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use.
CONCLUSION. Dentists may be able to refer postmenopausal women with suspected spinal osteoporosis for bone densitometry on the basis of dental panoramic radiographs with diagnostic performance similar to that of osteoporosis screening tools based on questionnaires.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
Some simple tools based on questionnaires have been designed to identify postmenopausal women who should undergo BMD testing [3–8]. The sensitivity of these tools in identifying postmenopausal women with low skeletal BMD was reported to be 90% or more, although the specificity was low. On the other hand, the response rate for questionnaires in the Canadian Multicentre Osteoporosis Study was only 42% [6]. This fact implies that many women may not respond to questionnaires if they have no knowledge of or interest in osteoporosis.
Recent studies indicate that dental panoramic radiography measures may be useful tools in identifying postmenopausal women with low skeletal BMD [9–14], high bone turnover rate [15], or high risk of osteoporotic fractures [16]. Because dental panoramic radiography is frequently performed for the diagnosis of diseases affecting the teeth and jaws in general dental practice, the incidental findings detected on dental panoramic radiographs maybe used to identify women who have no awareness of their low BMD and would benefit from BMD testing. However, little is known about whether these measures are valid in comparison with other simple risk indexes based on responses to questionnaires. The osteoporosis self-assessment tool (OST) is one of the simple tools based on questionnaires and is considered to be a useful index for identifying Asian and Caucasian postmenopausal women with low skeletal BMD [7, 17]. Comparison of diagnostic performances between dental panoramic radiography measures and the OST index would be of interest to explore the validation of the panoramic measures.
Furthermore, it is likely that the gynecologic histories such as hysterectomy, oophorectomy, or estrogen use might influence the diagnostic performance of screening tools by altering the findings of skeletal BMD tests in postmenopausal women [18, 19]. It is still unknown whether dental panoramic radiography measures can be used in postmenopausal women with such histories and in healthy postmenopausal women.
The purpose of this study was therefore to examine the diagnostic performances of dental panoramic radiography measurements and the OST index in postmenopausal women with and without histories of hysterectomy, oophorectomy, or estrogen use.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
Excluded from the study were postmenopausal women who had used tobacco or medications that affect bone metabolism except estrogen or who had metabolic bone diseases, diabetes, significant renal impairment, bone-destructive lesions in the jaw, nonvertebral osteoporotic fractures, and vertebral osteoporotic fracture detected on radiography at skeletal BMD assessment. The vertebral fracture was assessed using a semiquantitative assessment [20]. All subjects gave informed consent before inclusion. Hiroshima University institutional human subjects committee approved obtaining dental panoramic radiographs in subjects who had given informed consent.
BMD at the lumbar spine (L2–L4) was measured by a dual-energy X-ray absorptiometry (DEXA) scanner (DPX-alpha, Lunar). The in vivo short-term precision error for spine BMD in our clinic is 1.0%. Spine BMD was categorized as normal (T score > –1.0), osteopenic (T score, –1.0 to –2.5), or osteoporotic (T score < –2.5), according to the World Health Organization (WHO) classification [21]. Height and weight were measured at the time of the DEXA scanning.
All dental panoramic radiographs were obtained at the time of the DEXA scan with an AZ-3000 scanner (Asahi) at 12 mA and 15 sec; the kilovoltage varied between 70 and 80 kV. Screens of speed group 200 (HG-M, Fuji Photo film) and film (UR-2, Fuji Photo film) were used. Two dental panoramic radiography measures, mandibular cortical shape and width, were estimated on dental panoramic radiographs by one oral radiologist with 16 years of clinical experience.
Measurement of mandibular cortical width was made bilaterally on the radiographs at the site of the mental foramen according to our previous study [10] (Fig. 1). We drew a line parallel to the long axis of the mandible and tangential to the inferior border of the mandible and constructed a line perpendicular to this tangent intersecting the inferior border of mental foramen, along which the mandibular cortical width was measured with a caliper. The mean cortical width on both sides of the mandible was used in this study. The coefficient of variation due to positioning and operator errors in cortical width measurements was less than 2%. Intraobserver variation in cortical width measurements was 0.1 mm, which was similar to the interobserver variation. The OST index was obtained from the integer of 0.2 times the patient's weight minus the integer of 0.2 times her age on the basis of a previous study [7].
|
Mandibular cortical shape on dental panoramic radiographs was determined by observing the mandible distally from the mental foramen bilaterally and categorized into one of three groups according to the method of Klemetti et al. [9] as follows: normal cortex, the endosteal margin of the cortex is even and sharp on both sides (Fig. 2); mildly to moderately eroded cortex, the endosteal margin shows semilunar defects (lacunar resorption) or appears to form endosteal cortical residues (Fig. 3); or severely eroded cortex, the cortical layer forms heavy endosteal cortical residues and is clearly porous (Fig. 4).
|
|
|
Overall agreements for intraobserver and interobserver performances were 92% and 82%, respectively. Characteristics between group A and group B were compared using the unpaired Student's t test or the chi-square test. For mandibular cortical shape, subjects were divided into two groups on the basis of the assessment of panoramic radiographs: women with and without an eroded mandibular cortex (eroded cortex). The subjects were also divided into two groups on the basis of BMD measurements of the lumbar spine: women with and without spinal osteoporosis (T score < –2.5). The sensitivities, specificities, predictive values, and accuracies for the identification of women with spinal osteoporosis by eroded mandibular cortex were calculated in dichotomous 2 x 2 tables in group A and group B. The likelihood ratio and 95% confidence interval (CI) for a positive risk-index result were also calculated as described by Simel et al. [22]. The likelihood ratio farther away from 1.0 indicates better performance for discriminating between subjects with and without the condition.
Receiver operating characteristic (ROC) curve analyses were used to determine the optimal cutoff thresholds of cortical width and OST index for the identification of spinal osteoporosis in group A. The risk-index range corresponding to a sensitivity of approximately 90% was chosen to define the low-risk group. The sensitivity, specificity, predictive value, accuracy, and likelihood ratio for the identification of women with spinal osteoporosis by optimal cutoff thresholds of cortical width and the OST index determined on ROC analyses in group A were calculated in group A and group B.
In the subgroup that excluded subjects with spinal osteoporosis, the likelihood ratios for the identification of women with spinal osteopenia (T score, –1.0 to –2.5) by cortical width, OST index, and cortical shape were also calculated in group A and group B. Data analyses were performed by using SPSS, version 8.0 (Statistical Package for the Social Sciences) for Windows (Microsoft). A p value of less than 0.05 was considered statistically significant.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
|
The area under the ROC curve (Az) for identifying women
with spinal osteoporosis in group A was 0.771 (95% CI, 0.678–0.864) for
cortical width and 0.829 (95% CI, 0.748–0.910) for the OST index. No
significant difference in Az was seen between them. When
the risk-index range corresponding to a sensitivity of approximately 90% was
chosen to determine the optimal cutoff threshold, the cutoff thresholds for
cortical width and the OST index were 4.5 mm and –1.0, respectively.
Tables 2 and
3 show the number of subjects
in each group with normal spine BMD, osteopenia, or osteoporosis in
postmenopausal women with and without histories of hysterectomy, oophorectomy,
or estrogen use as determined by cortical width (
4.5 mm), the OST index
( –1.0), and cortical shape (any cortical erosion).
|
|
Using the cutoff thresholds of 4.5 mm for cortical width and –1.0 for the OST index and selecting any cortical erosion, we found that the sensitivity and specificity, respectively, for identifying women with spinal osteoporosis were 89.5% and 33.9% for cortical width, 86.8% and 57.8% for the OST index, and 86.8% and 63.6% for cortical shape in group A (Table 4). The specificity and accuracy for cortical width were significantly lower than those for the OST index and cortical shape in this group. No significant difference in the diagnostic performance was found between the OST index and cortical shape in group A.
|
The sensitivity and specificity, respectively, for identifying women with spinal osteoporosis were 92.5% and 35.0% for cortical width, 72.5% and 58.1% for the OST index, and 80.0% and 64.1% for cortical shape in group B (Table 5). The specificity for cortical width was significantly lower than that for the OST index and cortical shape in this group. Accuracy for cortical width was significantly lower than that for cortical shape. No significant differences were seen in the diagnostic performances between the OST index and cortical shape in group B and for cortical width, the OST index, and cortical shape between group A and group B.
|
The likelihood ratio for positive risk-index results in identifying women with spinal osteoporosis was 1.35 (95% CI, 1.14–1.60) for cortical width, 2.06 (95% CI, 1.62–2.63) for the OST index, and 2.39 (95% CI, 1.83–3.12) for cortical shape in group A; and 1.42 (95% CI, 1.21–1.67) for cortical width, 1.73 (95% CI, 1.30–2.30) for the OST index, and 2.22 (95% CI, 1.67–2.97) for cortical shape in group B.
Furthermore, the likelihood ratio for a positive risk-index result for identifying women with spinal osteopenia was 1.27 (95% CI, 0.97–1.65) for cortical width, 1.50 (95% CI, 0.96–2.33) for the OST index, and 2.12 (95% CI, 1.24–3.65) for cortical shape in the group A; and 1.24 (95% CI, 0.93–1.59) for cortical width, 1.85 (95% CI, 1.16–2.94) for the OST index, and 2.77 (95% CI, 1.54–4.97) for cortical shape in group B.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
The sensitivity and accuracy for mandibular cortical shape and the OST index tended to be lower in postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use than in those without these histories, although the differences were relatively small for cortical shape compared with the OST index. The OST index was first developed to identify postmenopausal women with low hip BMD defined by BMD T scores equal to 2.5 or less in the Asian female population without oophorectomy and estrogen use [7]. However, Geusens et al. [17] showed that the diagnostic performance of the OST index was similar to that of simple calculated osteoporosis risk estimation and the osteoporosis risk assessment instrument; estrogen use is included in the calculation for both of these tools. The presence of subjects with a history of hysterectomy and oophorectomy may have more influence on the diagnostic performance of a simple screening tool based on questionnaires such as the OST index than that of cortical shape directly detected on radiographs.
The Az for identifying women with spinal osteoporosis by cortical width was 0.771 (95% CI, 0.678–0.864), corresponding to moderate accuracy [22]. This result was similar to that of a recent report in which the Az for identifying women with reduced BMD at the spine, hip, or forearm by means of cortical width detected on dental panoramic radiographs was 0.733 (95% CI, 0.618–0.830) in 74 Caucasian women [11]. This finding implies that mandibular cortical width detected on dental panoramic radiographs may be used worldwide as well, although the diagnostic performance of cortical width was lower than that of cortical shape and the OST index in our study.
Devlin and Horner [11]
suggested that a diagnostic threshold for cortical width of 3 mm (or less) may
be the most appropriate threshold for referral for bone densitometry in
Caucasian postmenopausal women. This threshold may contribute to the high
specificity and high positive predictive value; however, the low sensitivity
may lead to a large number of postmenopausal women with undetectable spinal
osteoporosis or osteopenia. In fact, if we selected the cortical width of 3 mm
(or less) as a threshold in this study, 21 (55%) subjects with spinal
osteoporosis in group A and 24 (60%) subjects with spinal osteoporosis in
group B could not be identified by cortical width. Because the risk-index
range corresponding to a sensitivity of approximately 90% was chosen to
determine the optimal cutoff threshold for cortical width in this study, the
positive predictive value was rather low. This finding resulted in the high
false-positive rate (
50%) that would lead to unnecessary additional
examinations and would decrease the cost-effectiveness. However, in comparison
with a general screening, this approach is efficient because it identifies a
subgroup (postmenopausal women with spinal osteoporosis).
In comparison with cortical width, the false-positive rate was 32% for the OST index and 27% for cortical shape in the group A. The false-positive rate was 31% and 28%, respectively, for these measures in group B. These rates indicate that a large number of postmenopausal women with spinal osteoporosis may be identified with minimal additional cost by both the OST index and cortical shape detected on dental panoramic radiographs.
This study has some design limitations. Subjects without histories of hysterectomy, oophorectomy, or estrogen use may not be representative of all Japanese postmenopausal women. Characteristics such as the proportion of subjects with a history of hysterectomy and oophorectomy or the duration of their estrogen use might limit our interpretation. Further investigation in a large number of populations would be necessary to confirm our findings.
Another limitation is that we evaluated the diagnostic performance in identifying postmenopausal women with spinal osteoporosis in this study, although other simple screening tools based on questionnaires were evaluated for the identification of postmenopausal women with low hip BMD or femoral osteoporosis. However, because the prevalence rate of vertebral fractures is higher in Japanese women than in Caucasian women and is higher than the prevalence rate of hip fractures in Japanese women [24, 25], we chose the lumbar spine as a screening site in this study. We previously showed that mandibular cortical BMD measured by quantitative CT (QCT) was significantly correlated with lumbar spine BMD measured on QCT in postmenopausal women [26]. This finding implies that the measurement of mandibular cortical bone may be useful for predicting spine BMD.
Although we did not refer to the identification of postmenopausal women with low hip BMD or femoral osteoporosis in this study, we recently showed that the diagnostic performance in identifying postmenopausal women with low spine BMD was almost similar to that in identifying those with low hip BMD when general dental practitioners assessed mandibular cortical shape on dental panoramic radiographs [13]. This finding implies that there may be no significant difference in the diagnostic performance between mandibular cortical shape and the OST index even when BMD of the femoral neck is used as a standard.
In conclusion, the diagnostic performance of mandibular inferior cortical shape detected on dental panoramic radiographs for identifying postmenopausal women with spinal osteoporosis was similar to that of the OST index developed for the Asian female population. Cortical shape also may be useful for the identification of spinal osteoporosis in postmenopausal women with histories of hysterectomy, oophorectomy, or estrogen use. Dentists may be able to refer asymptomatic postmenopausal women with suspected spinal osteoporosis for bone densitometry using dental panoramic radiographs with diagnostic performance similar to that of other osteoporosis risk indexes based on questionnaires such as the OST index.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  F Yasar, S Sener, E Yesilova, and F Akgunlu Mandibular cortical index evaluation in masked and unmasked panoramic radiographs Dentomaxillofac. Radiol., February 1, 2009; 38(2): 86 - 91. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Taguchi, M Ohtsuka, T Nakamoto, Y Suei, Y Kudo, K Tanimoto, and A-M Bollen Detection of post-menopausal women with low bone mineral density and elevated biochemical markers of bone turnover by panoramic radiographs Dentomaxillofac. Radiol., December 1, 2008; 37(8): 433 - 437. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T Nakamoto, A Taguchi, M Ohtsuka, Y Suei, M Fujita, M Tsuda, M Sanada, Y Kudo, A Asano, and K Tanimoto A computer-aided diagnosis system to screen for osteoporosis using dental panoramic radiographs Dentomaxillofac. Radiol., July 1, 2008; 37(5): 274 - 281. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Taguchi, M Ohtsuka, M Tsuda, T Nakamoto, I Kodama, K Inagaki, T Noguchi, Y Kudo, Y Suei, and K Tanimoto Risk of vertebral osteoporosis in post-menopausal women with alterations of the mandible Dentomaxillofac. Radiol., March 1, 2007; 36(3): 143 - 148. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Taguchi, M Ohtsuka, T Nakamoto, K Naito, M Tsuda, Y Kudo, E Motoyama, Y Suei, and K Tanimoto Identification of post-menopausal women at risk of osteoporosis by trained general dental practitioners using panoramic radiographs Dentomaxillofac. Radiol., March 1, 2007; 36(3): 149 - 154. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K Ishii, A Taguchi, T Nakamoto, M Ohtsuka, P Sutthiprapaporn, M Tsuda, I Kodama, Y Kudo, H Sumida, Y Suei, et al. Diagnostic efficacy of alveolar bone loss of the mandible for identifying postmenopausal women with femoral osteoporosis Dentomaxillofac. Radiol., January 1, 2007; 36(1): 28 - 33. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P Sutthiprapaporn, A Taguchi, T Nakamoto, M Ohtsuka, P. Mallick, M Tsuda, I Kodama, Y Kudo, Y Suei, and K Tanimoto Diagnostic performance of general dental practitioners after lecture in identifying post-menopausal women with low bone mineral density by panoramic radiographs. Dentomaxillofac. Radiol., July 1, 2006; 35(4): 249 - 252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S Okabe, Y Morimoto, T Ansai, K Yamada, T Tanaka, S Awano, S Kito, Y Takata, T Takehara, and T Ohba Clinical significance and variation of the advanced calcified stylohyoid complex detected by panoramic radiographs among 80-year-old subjects. Dentomaxillofac. Radiol., May 1, 2006; 35(3): 191 - 199. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. White, K. Atchison, J. Gornbein, A Nattiv, A Paganini-Hill, S. Service, and D. Yoon Change in mandibular trabecular pattern and hip fracture rate in elderly women Dentomaxillofac. Radiol., May 1, 2005; 34(3): 168 - 174. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
