Automated osteoporosis risk assessment by dentists: A new pathway to diagnosis H. Devlin a, ⁎ , P.D. Allen b , J. Graham b , R. Jacobs d , K. Karayianni c , C. Lindh e , P.F. van der Stelt f , E. Harrison b , J.E. Adams b , S. Pavitt a , K. Horner a a School of Dentistry, University Dental Hospital, Higher Cambridge Street, Manchester, M15 6FH, UK b Imaging Science and Biomedical Engineering, University of Manchester, UK c Dental School, University of Athens, Greece d Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Katholieke Universiteit Leuven, Belgium e Faculty of Odontology, Malmő University, Sweden f Academic Centre for Dentistry, Amsterdam, The Netherlands Received 28 May 2006; revised 29 September 2006; accepted 29 October 2006 Available online 22 December 2006 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. © 2006 Elsevier Inc. All rights reserved. Keywords: Osteoporosis; Active shape modeling; Risk assessment; Mandible; Radiography Introduction Mandibular cortical width on dental panoramic radiographs is significantly correlated with bone mineral density at the hip [1], lumbar spine [2] and forearm [3], the most common sites of fracture related to osteoporosis in post-menopausal women. Measuring mandibular cortical width could be used for diag- nosis as a screening tool for osteoporosis. Taguchi et al. [2] found that mandibular cortical thickness was related to the bone mineral density of the third lumbar vertebra. Devlin and Horner [3] found that mandibular cortical width had moderate accuracy when used to diagnose skeletal osteopenia. Subsequent work [4] advised that a cortical thickness of less than 3 mm in the mental foramen region should be a trigger for referral for dual energy X-ray absorptiometry (DXA). While DXA facilities are often limited, millions of dental panoramic radiographs are taken every year across Europe. A recent study based in the United Kingdom, showed that 61% of Bone 40 (2007) 835 – 842 www.elsevier.com/locate/bone ⁎ Corresponding author. Fax: +44 161 275 6480. E-mail address: Hugh.Devlin@manchester.ac.uk (H. Devlin). 8756-3282/$ - see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.bone.2006.10.024