A. Cephalic index .
B. Mesocephalic index.
Ans:A. Cephalic Index
- Cephalic index (CI) = biparietal diameter (BPD)/occipitofrontal diameter (OFD) x 100 .
- The cephalic index was widely used by anthropologists in the early 20th century to categorize human populations by identification of race.
- It is now mainly used to describe individuals’ appearances and for estimating the age of fetuses for legal and obstetrical reasons to diagnose certain developmental disorders of the skull, such as craniosynostosis (premature fusion of the cranial bones), hydrocephalus , and positional deformation (breech presentation).
Racial difference in the skull:
|Type of skull||Cephalic index||Race|
|Dolichocephalic (long headed)||70-75||Pure Aryans, Aborigines and Negroes|
|Mesaticephalic (medium headed)||75-80||Europeans and Chinese|
|Brachycephalic (short headed)||80-85||Mongolian|