Association Between Changes in the Angle of Mandible and Reduced Bone Mineral Density

Objective: To establish an association between the angle of mandible on an orthopantomogram (OPG) with reduced bone mineral density of femoral neck and spine on Dual Energy X-ray Absorptiometry (DXA) scan. Study Design: Cross-sectional study. Place and Duration of Study: Institute of Basic Medical Sciences (IBMS), Dow University of Health Sciences (DUHS), Karachi, from December 2011 to July 2012. Methodology: Female subjects between 25 and 85 years of age were divided into premenopausal (Group-I) and postmenopausal (Group II) groups. Dual Energy X-ray Absorptiometry (DXA) scan was done to divide Group-I and Group-II into normal (pre A, post A), osteopenic (pre B, post B) and osteoporotic (pre C, post C) groups. Changes seen in angle of mandible on orthopantomogram (OPG) in subgroups of Group-I were compared with each other and with subgroups of Group-II. SPSS version 16 was used to carry out the statistical analysis. Intragroup significance was evaluated through One Way Analysis Of Variance (ANOVA). For intergroup significance independent samples t-test was applied. Results: The angle of mandible (A) was significantly decreased in Intragroup comparison of Group-II (0.035) between Post normal (Post A) vs. Post osteopenic (Post B) groups. Intergroup comparison between Group-I and Group-II (0.005) showed a significant decrease in angle of mandible between Pre osteopenic (Pre B) vs. Post osteopenic (Post B). Conclusion: As decrease in angle of mandible was observed at stage of osteopenia, it can be conveniently used for early detection of osteoporosis. (author)