Precondylar tubercles on the basiocciput of adult human skulls.

The basiocciput of 265 Indian adult human skulls was examined for precondylar tubercles, which are single or paired osseous formations anterior to the occipital condyles and foramen magnum. Of the 14% of skulls displaying these tubercles unilaterally or bilaterally, 5.3% demonstrated ridges, 4.9% showed spines and 3.8% exhibited processes. Sexual dimorphism was evident with female skulls showing a higher incidence (8.7%) compared with male skulls (5.3%). The corresponding atlas vertebrae were normal. These craniovertebral anomalies may have clinical relevance for lesions at the foramen magnum.