The influence of race on the position of the jugular bulb

The position of the jugular bulb (JB) is of great clinical significance to the otologist. A high and laterally situated jugular bulb may pose difficulties when dealing with the middle ear while a high and medially sited jugular bulb can create problems in neuro-otological surgery. This paper aims to study possible racial differences in the position of the jugular bulb. Fine-cut computed tomogram (CT) scans of temporal bones (in the axial plane) of 34 Caucasians and 34 Chinese were studied. The position of the jugular bulb was determined with reference to the midpoint of the lumen at the inferior limit of the cochlea (mpC). Of the 60 Caucasian and 58 Chinese temporal bones with identifiable jugular bulbs, 33 jugular bulbs of the Caucasian (55 per cent) and 34 jugular bulbs of the Chinese (58.6 per cent) were at the same height or higher than the mpC (p = 0.2; chi-squared test). The midpoint of the jugular bulb was 8.67 ± 1.73 and 8.61 ± 2.49 mm posterior to the mpC for the Caucasian and Chinese respectively (p = 0.2; t-test). However, the midpoint of the jugular bulb of eight Caucasian (24.2 per cent) and 22 Chinese (64.7 per cent) were medial to the mpC (p<0.001; chi-squared test). Race does not influence the height of the jugular bulb nor its position in the sagittal plane but can influence whether a high jugular bulb is medially or laterally situated.