Case-control study on self-reported osteoporotic fractures and mandibular cortical bone

Objectives, The purpose of this case-control study was to determine whether the radiographic appearance of the mandibular cortical bone in patients wh o were elderly and noninstitutionalized was related to a self-reported hist ory of osteoporotic fractures. Study design, Patients who had a billing statement at the School of Dentist ry dated between 1993 and 1996, who were older than 60. and who had a panor amic radiograph were invited to be interviewed regarding fracture history ( circumstances and year of fracture) and risk factors for osteoporosis. Case s (n = 93) were individuals reporting osteoporotic fractures (fractures occ urring after minor impact). Controls (n = 394) were individuals reporting t raumatic fractures (n = 105) or no fractures (n = 289). Blinded to case-con trol status, we evaluated the mandibular cortex on a panoramic radiograph a nd classified them as normal (even and sharp endosteal margin), moderately eroded (evidence of lacunar resorption or endosteal cortical residues), or severely eroded (unequivocal porosity). In addition, cortical thickness was measured below the mental foramen. Results. After adjustment for potentially confounding factors, the odds rat io for an osteoporotic fracture associated with moderately eroded and sever ely eroded mandibular cortices was 2.0 (95% CI, 1.2 to 3.3) and 8.0 (95% CI , 2.0 to 28.9), respectively. After adjusting for all potentially confoundi ng factors, we found that the cortex was 0.54 mm (or 12%) thinner in subjec ts with an osteoporotic fracture compared with controls (95% CI, 0.25 to 0. 84 mm). Conclusions. Subjects with a self-reported history of osteoporotic fracture s tend to have increased resorption and thinning of the mandibular lower co rtex.