[Expression of RANKL/OPG in male mandible of different ages]

To investigate the relationship between male osteoporosis and the expression of receptor activator of NF-κB ligand(RANKL) and osteoprotegerin(OPG)-mRNA in male mandible at different ages.

Between May 2008 and January 2009, bone tissues of the mandible were collected as the experimental material from 46 patients suffering from jaw facial deformity and extraction. The patients with periodontist, systemic disorder and smoking as well as drinking were excluded.They were divided into three groups: young group, whose age was 10-29 years old ;middle age group, whose age was 30-59 years old; aged group, whose age was 60-89 years old. The expression of RANKL mRNA and OPG mRNA was examined by real-time PCR. The data was analyzed using ANOVA followed by least significant difference (LSD) test with SPSS16.0 software package.

(1)Compared with the young group, RANKL mRNA level in mandible was 2.1-fold and 5.3-fold higher in the middle age and aged groups, respectively, whereas OPG mRNA level was 3.3-fold and 4.8-fold higher in middle age and aged groups, respectively. RANKL and OPG were positively correlated with age.(2)The ratio of RANKL/OPG in middle age group was lower than that of young group and old group,respectively.

(1)The expression of RANKL and OPG increases with age remarkably.(2)Bone formation of the mandible is activated in middle aged group. The formation is over absorption.(3)Bone formation of the mandible in aged group is at low level. Bone absorption exceeds bone formation.