Identifying dental panoramic radiograph markers for the screening of low bone mineral density in women age fifty and older

Osteoporosis is characterized as loss of bone mineral density and deterioration of bone architecture, with consequent susceptibility to fractures, even with minimal force.  Early detection of osteoporosis is an important public health goal because interventions such as drug therapy, exercise, and fall-prevention measures can be effective in preventing fractures.  The acceleration of bone degeneration during menopause causes post-menopausal women to be especially prone to complications arising from osteoporosis.  Dental radiographs have great potential as a screening tool for osteoporosis because of their wide availability, practicality, and low cost.  Their performance as screening tools, however, has yielded conflicting results^.1,2  The purpose of this study was to answer the following clinical question: “Do certain features of dental panoramic radiographs correlate strongly with the presence of osteoporosis in post-menopausal women?”  The authors hypothesize that there will be identifiable radiographic features that may aid in screening for osteoporosis in this population.  The specific aims of this study were to 1) To develop and implement a retrospective cohort study and to enroll subjects who were post-menopausal women with bone mineral density (BMD) measurements and panoramic dental x-rays 2) To identify which measurements taken from the panoramic x-rays can be used to screen post-menopausal women for osteoporosis.

Using a retrospective cohort study design, the authors enrolled a sample composed of female subjects who were 50 years of age or older and had a dental panoramic x-ray and a bone mineral density scan within two years of each other at the Massachusetts General Hospital between 2006 and 2012.  The predictor variables were average gonial angle, average antegonial angle, mandibular cortical bone integrity, periodontal disease status, and number of remaining teeth.  In addition, demographic (age, ethnicity) and medical data (BMI, bisphosphonate usage) were obtained as additional predictor variables. The primary outcome measure was BMD T-score as determined by dual emission x-ray absorptiometry, the gold standard for diagnosing osteoporosis.

Descriptive and logistic regression statistics were computed to analyze the relationship between the predictor variables and decreased BMD.  P-values < 0.05 were considered significant.  The sample was composed of 274 subjects with a mean age of 64 ± 9.3 years.  The average BMD T-score was -1.59 ± 1.11.  The sample was composed of 27.11% normal (BMD T-score > -1), 50.92% osteopenic (BMD T-score between -1 and -2.5), and 21.98% osteoporotic (BMD T-score < -2.5).  Of the predictor variables examined, mandibular cortical bone integrity (p=0.019), age (p<0.0001), BMI (p<0.0001), and bisphosphonate usage (p=0.037) showed significant correlations with a BMD diagnosis of osteopenia/osteoporosis.  Average gonial angle (p= 0.5), average antegonial angle (p=0.2), number of remaining teeth (p=0.1) and periodontal status (p=0.3) did not demonstrate significance.  In a multivariate logistic regression analysis, mandibular cortical bone outline did not demonstrate significance (p= 0.6), while age and BMI remained significant (p<0.0001).  In conclusion, given mandibular cortical bone integrity’s significance in univariate analysis and biologic plausibility, it may be useful as a risk assessment tool and recommendation for a bone mineral density scan, while other panoramic measurements (gonial angle, antegonial angle, periodontal status) have limited utility as screening tools.

1. Passos JS, Gomes Filho IS, Sarmento VA, Sampaio DS, Gocalves FP, Coelho JM, Cruz SS, Trindade SC, Cerqueira EM. Women with low bone mineral density and dental panoramic radiography. Menopause. June 2012;19(6):704-709.

2. Dutra V, Devlin H, Susin C, Yang J, Horner K, Fernandes AR. Mandibular morphological changes in low bone mass edentulous females: evaluation of panoramic radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Nov;102(5):663-668.