Formula for cervical vertebral bone age of Vietnamese people from 7 to 18 years old

INTRODUCTION: The purpose of this study was to establish a formula for cervical vertebral bone age (CVBA) based on the morphological changes of cervical vertebrae on cephalometric radiographs in Vietnamese subjects between 7 and 18 years of age. MATERIALS AND METHODS: This study included 180 children and adolescents (92 boys, 88 girls), between 7 and 18 years of age, selected from the craniofacial morphology studies of the Faculty of Odonto-Stomatology, Ho Chi Minh University of Medicine and Pharmacy. The cephalometric and hand-wrist radiographs of each subject were taken simultaneously and evaluated. Eleven hand-wrist skeletal maturity indicators of Fishman were grouped into five stages: initiation and acceleration, transition, deceleration, maturation, and completion stage. A multivariate regression analysis was conducted to assess the correlation between the stages of hand-wrist BA and the morphological characteristics of the second, third, and fourth cervical vertebrae on the cephalometric radiographs. RESULTS: A formula for CVBA was proposed as follows: CVBA = 1.92+ 0.04 * α2 + 0.03 * α4 –1.12*AB3/BC3 + 3.17 * h4/w4, where α2 and α4 are anteroinferior border angles of C2 and C4; AB3/BC3 is the ratio of inferior to anterior dimension of C3; h4/w4 is the ratio of height to width of C4. The means and standard deviations of five stages of CVBA will be as follows: CVBA I= 1.527 ± 0.906; CVBA II= 2.732 ± 0.568; CVBA III= 3.762 ± 0.589; CVBA IV= 5.077 ± 0.840; and CVBA V= 5.820 ± 0.661. CONCLUSION: The quantitative CVBA method could be useful to assess the level of skeletal maturation in orthodontic and orthopedic treatments.