Cervical vertebral bodies undergo substantial morphological development during the first two decades of life that are used clinically to visually determine skeletal maturation with the cervical vertebral maturation index (CVMI). CVMI defines six stages that capture the morphological transformations from 6 years to 18 years. However, CVMI has poor reproducibility given its qualitative nature and does not account for sexual dimorphism. This study aims to quantify the morphological development of the cervical vertebral bodies C2–C7 in size (height and depth) and shape and examine the emergence of sexual dimorphism. Using 115 (70 M;45F) computed tomography studies from typically developing individuals ages 6 months to 20 years, landmarks were placed at the margins of the C2–C7 cervical vertebral bodies in the midsagittal plane for size and shape analysis. Findings revealed a dichotomy in the growth trends of height versus depth. The C2–C7 growth in depth gained the majority of the adult size by age 5 years, while the C3–C7 growth in height displayed two periods of accelerated growth during early childhood and puberty. Significant sex differences were found in height and depth growth trends and the form-space ontogenetic trajectories during puberty, with minor but evident differences emerging at age 3 years. Female C2–C7 depth measures were smaller than males at all ages. However, sex differences in height became evident due to males continuing to grow after females reach maturity. Findings quantify the morphological developmental stages of CVMI and emphasize the need to account for sex differences when assessing skeletal maturation.
Bibliographical noteFunding Information:
This research was funded, in part, by National Institutes of Health Grant R01 DC6282 from the National Institute on Deafness and Other Communication Disorders (NIDCD), and Core Grants P30 HD03352 and U54 HD090256 from the National Institute of Child Health and Human Development (NICHD). There was no involvement of the funding sources in the research design, data collection, analysis, interpretation, writing of this paper or the submission for publication. All authors declare there was no conflict of interest in the research reported in this study/paper. We thank Michael Kelly for assisting with the development of the landmarking protocol and Ellie Fischer and Anna Buchholz for assistance in landmark placement.
© 2020 American Association for Anatomy.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics