Identification, Classification, and Distribution of the Suprameatal Crest in Multi‐Regional Modern and Extinct Human Populations: A CT Imaging Study with Clinical Correlates

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The temporal bone houses one of the most primitive sensory apparatus in its arsenal – balance, and is considered an evolutionarily conserved skeletal element of the skull. While the cranial base portion of the temporal bone exhibits a high plastic threshold to change, variation in other cranial portions subject to alteration may signal adaptive evolutionary modifications. The suprameatal crest (SC) is a clinically important osteological landmark in surgical approaches to the mastoid air cells, but few studies have examined its frequency and distribution in multi‐regional human populations (MRHP). This study identifies, categorizes and tracks the distribution of the SC in three distinct regional populations (European, African, and Inuit) and examines the degree of expression in three extinct fossil human specimens. CT imaging coupled with inspectional analysis of dry skulls showed a highly variable appearance of the SC morphology. In both the African and Inuit groups 90% presented with a SC morphology compared with only 70% in the European sample. The African and Inuit showed an even distribution in their degree of expression of a SC scoring 56% pronounced and 44% traced and 44% pronounced and 56% traced respectively. The European sample showed a 71% traced and a 29% pronounced SC morphology while all three fossils presented with a pronounced SC morphology. Further studies should investigate MRHP to document variation and the reliability of the SC as a viable surgical landmark.