Frequency of portrayal of foramen transversarium of the second cervical vertebra on rotational panoramic radiographs

OBJECTIVES: To determine the prevalence of portrayal of the foramen transversarium of the second cervical vertebra on rotational panoramic radiographs. METHODS: A stratified random sample of 1600 diagnostic-quality rotational panoramic radiographs were retrospectively reviewed. Approximately 100 radiographs each for males and females were reviewed for each of the decades of life up to age 69 and for subjects 70 or older. RESULTS: The foramen was portrayed 29.3% of all radiographs, 35% of females and 22.6% of males. However, when considering only those radiographs in which cervical vertebrae were visible, the foramen was more frequently portrayed in males than in females. Portrayal of the foramen did not differ substantially among age groups. CONCLUSIONS: The foramen transversarium is found sufficiently often on rotational panoramic radiographs that this structure should be identifiable by clinicians who use these images.