Mandibular cortical erosion detected on dental panoramic radiographs (DPRs) may be useful for identifying
womenwith 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 awebsite 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 inthis 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 theOsteoporosis 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 DPRswere 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 valuesN0.6) in 36 (60%) observers. This was significantly
increased in observers who specialized in oral radiology (Pb0.05). In the 36 observers with sufficient intraobserver
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.
Radiographs, Dentist, Screening, Menopause