Abstract:
The variable development of the zygoma, dictating its shape and size variations
among ancestral groups, has important clinical implications and valuable
anthropological and evolutionary inferences. The purpose of the study was to review
the literature regarding the variations in the zygoma with ancestry. Ancestral
variation in the zygoma reflects genetic variations because of genetic drift as well as
natural selection and epigenetic changes to adapt to diet and climate variations with
possible intensification by isolation. Prominence of the zygoma, zygomaxillary
tuberosity, and malar tubercle have been associated with Eastern Asian populations
in whom these features intensified. Prominence of the zygoma is also associated
with groups from Eastern Europe and the rest of Asia. Diffusion of these traits
occurred across the Behring Sea to the Arctic areas and to North and South
America. The greatest zygomatic projections are exhibited in Arctic groups as an
adaptation to extreme cold conditions, while Native South American groups also
present with other features of facial robusticity. Groups from Australia, Malaysia, and
Oceania show prominence of the zygoma to a certain extent, possibly because of
archaic occupations by undifferentiated Southeast Asian populations. More recent
interactions with Chinese groups might explain the prominent cheekbones noted in
certain South African groups. Many deductions regarding evolutionary processes
and diversifications of early groups have been made. Cognisance of these ancestral
variations also have implications for forensic anthropological assessments as well as
plastic and reconstructive surgery. More studies are needed to improve accuracy of
forensic anthropological identification techniques.
