Variability In The Size Of The Mastoid Process In African-American And Caucasian Populations Of Male And Female Skulls

Salim, Faddi, Tone Shamon, Robert Trecapelli, Greg Grabowski, Mary Tracy-Bee, and James Montante


Variation in mastoid process morphology related to gender and race was investigated in modern human skulls from Caucasian and African-American populations located at the Cleveland Museum of Natural History.  The mastoid process is a projection of bone that lies behind and below the ear.  It has great clinical relevance due to the many muscles that attach to it and because, when infected, causes painful mastoiditis which may lead to death. A significant level of symmetry was identified between the right and left sides of all skulls (p<0.001).  However, a significant difference was not found in any mastoid process dimensions related to gender or race for mastoid morphology nor for height or size of the external auditory meatus (>0.05).  This would be expected in light of the known lack of difference among the hearing apparatus of all four groups of female Caucasian, female African American, male African-American and male Caucasian.