***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE Bone loss is a common feature of periodontitis and osteoporosis . Both diseases may share common etiologic agents which may either affect or modulate the process of both diseases . The purpose of this study was to evaluate the relationship between systemic bone mineral density ( BMD ) and periodontal disease among older people . MATERIAL S AND METHODS Among all 4,542 inhabitants aged 70 years according to a registry of residents in Niigata city in Japan , 600 people were selected r and omly . One hundred and eighty-four subjects who did not have diabetes mellitus , whose blood sugar was < 140 mg/dl , who had more than 20 teeth , who were non-smokers , and who did not take medication for osteoporosis , were included in the study . Four dentists performed clinical evaluations on probing attachment level ( PAL ) .  We also utilized the data on BMD of the heel , which we measured using an ultrasound bone densitometer . Follow-up clinical surveys were done by measuring PAL after 3 years .  Finally , 179 subjects who could participate in both the baseline and the follow-up examinations were included in the analysis . After dividing the subjects into an osteopenia group ( OG ) and non-osteopenia group ( NOG ) , we evaluated the relationship between BMD and the number of progressive sites which had > or =3 mm additional attachment loss during 3 years after controlling the known confounding factors . RESULTS The mean number of progressive sites for the OG and the NOG , respectively , were 4.65+/-5.51 and 3.26+/-3.01 in females and 6.88+/-9.41 and 3.41+/-2.79 in males . Two-way analysis of variance was performed to discriminate among effects of gender , BMD , and gender-BMD interaction . A significant effect of BMD ( OG or NOG , p=0.043 ) with a significant interaction ( p=0.038 ) was observed . Furthermore , BMD was associated with the number of progressive sites which had > or =3 mm additional attachment loss during the 3 years ( p=0.001 ) by multiple linear regression analysis . CONCLUSIONS This study suggested that there was a significant relationship between periodontal disease and general BMD Bone loss is a feature of both periodontitis and osteoporosis , and periodontal destruction may be influenced by systemic bone loss . This study evaluated the association between periodontal disease and bone mineral density ( BMD ) in a cohort of 1347 ( 137 edentulous ) older men followed for an average of 2.7 years . Participants were recruited from the Osteoporotic Fractures in Men Study . R and om half-mouth dental measures included  clinical attachment loss ( CAL ) , pocket depth ( PD ) , calculus , plaque , and bleeding . BMD was measured at the hip , spine , and whole-body , by dual-energy x-ray absorptiometry , and at the heel by ultrasound . After adjustment for age , smoking , race , education , body mass index , and calculus , there was no association between number of teeth , periodontitis , periodontal disease progression , and either BMD or annualized rate of BMD change . We found little evidence of an association between periodontitis  and  skeletal BMD among older men Many studies have attempted to define the relationship between osteoporosis and periodontal disease . Most studies support a positive association between these common diseases ; however , many are cross-sectional in nature , include relatively small sample sizes , and have inadequate control of potential confounding factors , such as age , gender , hormone intake , race , and smoking , limiting our underst and ing of the nature of the relationship between these diseases . Prospect i ve studies are needed to confirm or refute a causal relation ( 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 r and omly 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 question naire 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 N and 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 A considerable amount of work has been performed on methods of detecting individuals with low bone mass at an early stage . Some research ers have considered if dental radiographs could have a role in the detection of individuals with osteoporosis . A basic requirement for this would be that bone mass in the jaw relates significantly to that of other skeletal sites in which osteoporosis is a significant problem . The first aim of this study was to investigate the relationship between m and ibular bone mineral density ( BMD ) and that of other skeletal sites commonly used for bone densitometry in the detection of osteoporosis . The second aim was to assess the validity of m and ibular BMD as a predictor of BMD in these other sites . 40 edentulous females underwent dual energy X-ray absorptiometry ( DXA ) of the lumbar spine ( L2-L4 ) , DXA of the right femoral neck , single photon absorptiometry ( SPA ) of the proximal and distal forearm and DXA of the m and ible . Significant correlations were observed between BMD in the m and ibular body , ramus and symphysis and all other skeletal sites ( p < 0.02 ) . Five patients ( 12.5 % ) had age matched Z-scores of -1.0 or lower in all three non-m and ibular sites ( lumbar spine , femoral neck and forearm ) . Using these patients as the proportion of the population with a positive finding of " low bone mass " , the sensitivity and specificity of m and ibular BMD in predicting low bone mass for these patients was determined . Where a diagnostic threshold for low m and ibular BMD was set at one st and ard deviation below the mean , the m and ibular body BMD measurement gave high sensitivity ( 0.8 ) and specificity ( 0.97 ) , the symphysis BMD low sensitivity ( 0.4 ) but a high specificity ( 0.77 ) , while the ramus BMD had a moderate level of sensitivity ( 0.6 ) and high specificity ( 0.91 ) . It is concluded that m and ibular BMD assessed by DXA correlates significantly with BMD measurements of other important skeletal sites . The higher correlation coefficients and the greater sensitivity and specificity for the body of m and ible suggest that this site should be used for any potential clinical application of dental radiographs in detection of osteoporosis The aim of the present study was to examine the periodontal conditions in an age cohort of 70-year-old women and compare an osteoporosis group with a control group with normal bone mineral density . 210 women 70 years old and r and omly sample d from the population register of the community of Linköping were examined .  Bone mineral density ( BMD ) of the hip was measured by dual energy X-ray absorptiometry .  19 women were diagnosed with osteoporosis ( BMD below 0.640 g/cm2 in total hip ) . 15 of them accepted to participate in the study . As a control group 21 women with normal bone mineral density ( BMD exceeding 0.881 g/cm2 ) were r and omly selected from the initial population . The clinical examination included registration of the number of remaining teeth , dental plaque and periodontal conditions . The radiographic examination included a dental panorama and vertical bite-wing radiographs . The subjects also answered a question naire about their general health , age at menopause , concurrent medication , smoking and oral hygiene habits . The results from this study showed no statistically significant differences in gingival bleeding , probing pocket depths , gingival recession and marginal bone level between the women with osteoporosis and the women with normal bone mineral density . In conclusion , the present r and omly selected and controlled study of osteoporotic and non-osteoporotic women , showed no statistically significant differences in periodontal conditions or marginal bone level . As periodontitis as well as osteoporosis are associated with age , our study of a well-defined age cohort is of interest , but the results should be interpreted with caution since the compared groups are small BACKGROUND Recent research suggests that osteopenia may be a predisposing factor for periodontal tissue destruction . If so , then a relationship should exist between measures of systemic bone mineral density and periodontal tissue destruction . The purpose of the present cross-sectional study was to evaluate the association between systemic bone mineral density and the clinical signs of periodontal tissue destruction in a large population of elderly dentate women . METHODS A total of 292 dentate women ( average age 75.5 years ) were r and omly selected for a cross-sectional periodontal sub study from participants at the Pittsburgh Field Center of the Study of Osteoporotic Fractures ( SOF ) , a prospect i ve study of a cohort of elderly women ( age > or = 65 years at baseline ) to determine risk factors for fractures . Bone mineral density ( BMD ) was measured using single photon absorptiometry ( radius , calcaneus ) and dual energy x-ray absorptiometry ( hip , spine ) . Oral health examinations , including periodontal probings and an assessment of bleeding on probing  , were made using an NIDR probe at 3 buccal sites of all teeth . Multiple regression models were used to assess the association between bone mineral density and measures of periodontal disease status while controlling for potential confounders . Periodontal status variables examined included : average loss of periodontal attachment ( LOA ) ; number of sites with at least 4 mm LOA ; number of sites with at least 6 mm LOA ; number of sites with bleeding on probing ; and deepest probing depth per person . RESULTS This study found no statistically significant association between the 5 indicators of periodontal disease and measures of systemic BMD at 8 anatomic sites after controlling for age , smoking , and number of remaining natural teeth . Some suggestive findings support a weak association between generalized osteopenia and periodontal disease . CONCLUSIONS Systemic osteopenia is , at best , only a weak risk factor for periodontal disease in older non-black women 
    Output:
    
The majority of the studies suggested a relationship between osteoporosis and periodontitis .