Bone mineral density in periodontally healthy and edentulous postmenopausal women

(Osteoporosis is the most common metabolic disease among postmenopausal women. Reduced masticatory function caused by tooth loss may be a contributing risk factor of osteoporosis. The present study examined the effect of dentate state on skeletal bone mineral density (BMD) in postmenopausal women. Fourteen periodontally healthy dentate subjects (group H; mean age: 64.0 + 5.5 years) and 12 edentulous subjects (group E; mean age: 67.1 + 2.9 years) were randomly selected from the clinics of the departments of Periodontology and Gerodontology, respectively. Informed consent was obtained from all participants. BMD of the lumbar spine (L2-L4) was measured by dual energy x-ray absorptiometry. In addition, occlusal force was measured in 11 group H subjects and 8 group E subjects by using an occlusal diagnostic system. Risk factors associated with osteoporosis including age, calcium intake, physical activity, and cigarette smoking and causes of tooth loss were assessed by interview and questionnaire sent to all participants. The BMD of group H was 1.07 t 0.21 g/cm2 and that of group E was 0.89 + 0.17 g/cm2, which was significantly different(P< 0.05). The occlusal force of group H and E patients was 312.4 + 148 Nand 56.3 + 36 N, respectively, which was significantly different (P< 0.05). Risk factors such as calcium intake, physical activity, and smoking did not differ significantly between the 2 groups. Thus, the periodontally healthy dentate women, who showed about 6 times higher occlusal force than edentulous women, maintained significantly higher BMD of the lumbar spine than edentulous women. Our results suggest that sufficient masticatory function with periodontally healthy dentition may inhibit or delay the progress of osteoporotic change in skeletal bone or that edentulous women may be more susceptible to osteoporosis.