Odontoid process angulation range in a South African skeletal population sample: An osteological study

Background: This study investigated the angulation of the odontoid process in a South African skeletal population to establish normative vertical angulation in the sagittal plane and assess variations across population affinity groups, biological sexes, and age categories. The study also investigated standardizing techniques for measuring the angle of the odontoid process. Methods: A cross-sectional study was conducted on 200 cervical axis vertebrae from the Raymond A. Dart Collection. Angulation measurements were taken using digital photographs, ImageJ software and statistical analyses (one-way ANOVA and t-tests). Results: The mean odontoid process angulation (degrees; °) across the sample was 60.45° (±3.10°). No statistically significant differences in angulation were found. Minor variations were observed, with males (60.77° ± 2.94°) showing a slightly higher mean angulation than females (60.08° ± 3.25°). The age groups, “20–40 years” (60.71° ± 3.56°) and “41–55 years” (60.43° ± 3.04°), displayed greater angulation than the 56–70 years age group (60.19° ± 2.68°). Population affinity groups showed that the Black African group had a mean angulation of 60.57° (±3.01°), the White group had 60.06° (±3.04°), and the Coloured group had a slightly higher mean of 60.64° (±3.26°). Conclusions: The study concluded there are statistically insignificant differences in the odontoid process angulation based on population affinity, sex, and age. The findings contribute to a better understanding of cervical spine anatomy and assist in clinical interventions related to the cervical spine.