The Dense Soft Tissues between the larynx and the spine should be examined. If there is swelling or distortion, this can indicate an underlying fracture.
Learning bite:
In neck flexion, there may be an apparent increase in the soft tissue anterior to C1 and C2. This is most marked in young children due to the laxity of their soft tissues. The x-ray above demonstrates anterior soft tissue swelling in a 1-year-old (click on the x-ray to enlarge). The neck should be extended to eliminate physiological rather than pathological soft tissue enlargement.
Concavity of the soft tissue above and below the arch of C1 suggests a physiological rather than a pathological cause however a high suspicion of injury is advised