The Study Of The Correlation Between The Cervical Vertebra Bone Age And The Degree Of Second Molar Calcification Of Chinese Han Nationality Adolescents In Urumqi

Objective:To study the correlationship between the cervical vertebra bone age and the degree of mandibular second molar calcification of Chinese Han Nationality adolescents in Urumqi. Discusses the application value of two indexes in orthodo-ntic clinic and provide a theoretical basis for judgment and prediction of growth a-nd development stage. Methods: 300 cases of Urumqi 9~15 years old adolescents(128 male and 172 female) of cephalometrics and panoramic radiograph. Using th-e improved cervical assessment of Farman and Hassel to analysis the cervical vert-ebra bone age of patients and Demirjian A~H eight calcified stage assessment to analysis the left mandibular second molar development, statistical analysis was used to explore the relationship between the three. Results:(1)With the spearman correla-tion analysis, in the combined group, the correlation between the cervical vertebra bone age and mandibular second molar calcification degree was highly related(r=0.718, P<0.01).The quality of relationships in male group(r=0.780, P<0.01) is hig-her than that of female group(r=0.661, P<0.01). The difference between the two groups was significant.(2)In the combined group, the positive likelihood ratio of jud-gments of the initial period of development by molar calcification level D is18.49,and the positive likelihood ratio of judgments of the mature stage of development by molar calcification level H is 8.48. In the female group, the positive likelihood ratio of judgments of the initial period of development by molar calcification lev-el D is 41, and the positive likelihood ratio of judgments of the mature stage of development by molar calcification level H is 7.07.In the male group, the positive likelihood ratio of judgments of the initial period of development by molar calcific-ation level D is 41, the positive likelihood ratio of judgments of the mature stageof development by molar calcification level H is 7.07 and the positive likelihood ratio of judgments of the transition period of development by molar calcification le-vel F is 6.35. Conclusion: Han Nationality adolescents cervical vertebra bone age were significantly associated with the calcification degree of mandibular second m-olar. When the development stage judged by the calcification degree of mandibular second molar, the molar calcification level D can be used to judge the initial peri-od of development in both male and female; the molar calcification level H can b-e used to judge the mature stage of development in male; in clinical orthodontic still needs to assess the patient’s stage of growth and development with age, cervic-al vertebra bone age and dental calcification degree.