The Eruption Of The Mandibular Incisors In 660 Urban Children Of Nanchang East Lake Distric And The Expression Of OPG And RANKL In Gingival Crevicular Fluid

Objective: By investigating the urban children aged from 4 to 7 in Nanchang East Lake District area.To know the eruption of their mandibular central incisor and understand the start time of children teeth eruption in oral.To provide the useful reference data for the children healthcare work whom in mixed dentition period.Observation the Receptor activator of nuclear factor-kB ligand and the Osteoprotegerin of mandibular incisor teeth in gingival crevicular fluid and to explore the roles of Receptor activator of nuclear factor-kB ligand and the Osteoprotegerin of mandibular central incisors in children teeth eruption.Methods: By using stratified sample survey method.Extract 5 kindergartens and5 primary schools in Nanchang East Lake District area.The children aged from 4 to 7as the investigation objects,a total of 660 children,including 335 girls and 325 boys.Through directing inspection on their oral teeth and using oral questionnaire to collect mandibular incisor eruption time.In the end,we used SPSS20.0 software for statistical analysis.The subjects were grouped into 5years old and 6 years old.Each group was devided into one group is anatomical crowns appear 1/2 group,32 children,the other group is all anatomical crowns appeared,32 children,using absorbent paper point to collect the subjects' gingival crevicular fluid,using OPG and RANKL kits and both concentrations were measured by ELISA method,we used SPSS20.0 software for statistical analysis.Results: By this survey,the boys' mandibular incisors eruption at an average age of(5.86±0.40),the girls' mandibular incisors eruption at an average age of(5.73±0.45).The girls' average eruption age of mandibular incisor are advanced than boys',that has statistically significance(F = 2.061,P = 0.001),but teeth eruption age in left and right side incisor have no statistically significance(F = 0.011,P = 1.069).In 5 years old group the anatomical crown appear 1/2,the average OPG is(246.17±58.87)mg/ml,anatomical full eruption group,the average OPG is(240.12±62.55)mg/ml,their difference have no statistically significant(F = 0.089,P =0.986).In 5 years old group the anatomy crown with 1/2 group,the average RANKL is(41.79 ±15.61)mg/ml,anatomical crown with full eruption,the average RANKL is(36.18 ± 12.59)mg/ml,the two groups appear no statistically significant(F = 1.257,P = 0.279).In 6 years old group the anatomical crown appear 1/2,the average OPG is(250.18±56.77)mg/ml,anatomical full eruption group,the average OPG is(243.36±65.51)mg/ml,their difference have no statistically significant(F=0.093,P=0.895).In 6 years old group the anatomy crown with 1/2 group,the average RANKL is(39.87±14.47)mg/ml,anatomical crown with full eruption,the average RANKL is(37.89±13.52)mg/ml,the two groups appear no statistically significant(F=1.312,P=0.237).The correlation analysis of OPG and RANKL in the 1/2 groups of children at the age of 5 was analyzed,r=0.70,r>0;The correlation analysis of OPG and RANKL in the group of children aged 5 years of age group was analyzed,r=0.79,r>0;The correlation analysis of OPG and RANKL in the 1/2 groups of children at the age of 6 was analyzed,r=0.81,r>0;The correlation analysis of OPG and RANKL in the group of 6 year olds was analyzed,r=0.76,r>0.Conclusion: The survey results show that in Nanchang East Lake Distric,the mandibular incisors eruption time are relatively concentrated on 5 years old and 6years old,the eruption time of male is(5.86±0.40)years old,female is(5.73±0.45)years old,that is different from other cities.This also prompt that children's permanent incisor eruption time have certain differences and we should be attention to these difference.In clinical work we should give oral health plan to the children in different area according to the time of their permanent teeth eruption.The content of OPG and RANKL may changing during the individual teeth eruption procession of mandibular permanent incisors both in 5 years old group and 6 years old group,OPG and RANKL have correlation,suggesting that both of them play a certain role in the teeth eruption.