Cervical Bone Age

Bone age which was an important index was extensively implied to value the development degree of adolescents.The scholars hoped to find a conveniently identified skeletal indicator which could represent the development degree of adolescents.The aim of this study was to obtain a method to calculate Cervical vertebral bone age of Chinese girls as to evaluate maturity in a detailed and objective manner on cephalometric radiographs,and to test the reasonability of this method. 1,A study on accuracy in cervical vertebral bone age:An investigation of error in landmark identification The purpose of this study was to test the error of landmark identification of cervical vertebral image in cephalometric radiograph,as to vertify the reliability of a researcher. The author identified 16 landmarks two times accoding to ten cephalometric radiograph selected randomly,and the measurements were assisted by computer,then the mean error of each landmark and measurements were determined.The following results were obtained:The mean error of each landmark was lower than 0.5 ㎜,and there were no significant differences in measurements.These results suggest that the error of traditional landmark identification of cervical vertebral image in cephalometric radiograph did not effect the accuracy of measurements. 2,The study of age groups on regression formula to obtain cervical vertebral bone age The purpose of this study was to get the best age groups on regression formula to obtain cervical vertebral bone age. Using cephatometric radiographs of 191girls (ages 10.0-18.9) ,we measured cervical vertebral bodies with Winceph7.0. Successively 8 regression formulae for obtaining cervical vertebral bone age was determined from the ratios and the chronological age using a stepwise multiple regression analysis.To combine the fitting degree between the model and data with clinical practice so as to get the best age group. The following results were obtained:The 10.0-14.9,10.0-15.9,10.0-17.9 age groups are more fit for obtaining cervical vertebral bone age. These results suggest that the 10.0-14.9 age group apply for girl before puberty, the 10.0-17.9 age group apply for girl before puberty and after puberty. 3,The study of reasonability to obtain cervical vertebral bone age The purpose of this study was to analyse reasonability to obtain cervical vertebral bone age.Using cephatometric radiographs of 240girls (ages 10.0-17.9 years),we measured cervical certebral bodies and determined a regression formula to obtain cervical vertebral bone age.Next,using cephatometric radiographs of another 60 girls(ages 11.0-16.9 years),we tested the reasonability of the regression formula about cervical vertebral bone age.The following results were obtained:⑴a regression formula was determined to obtain cervical vertebral bone age based on ratios of measurements in the third and fourth cervical certebral bodies;⑵the correlation coefficient for the relationship between cervical vertebral bone age and chronological age (0.905)was no significant differences (p<0.05) ;and ⑶the difference (absolute value) between the cervical vertebral bone age and chronological age(0.664 years) was no significant differences (p<0.001).These results suggest that the regression formula to obtain cervical vertebral bone age are reasonable.Using cervical vertebral bone age might be possible to evaluation maturity in a detailed and objective manner on cephalometric radiographs.