cranial index vs cephalic index

cranial index and cephalic index both are nouns.

Word	Noun	Adjective	Verb	Adverb
cranial index	Yes	No	No	No
cephalic index	Yes	No	No	No

As nouns, cranial index and cephalic index are synonyms defined as:

cranial index and cephalic index: ratio (in percent) of the maximum breadth to the maximum length of a skull

Other synonyms of cranial index include breadth index.

cranial index (noun)	cephalic index (noun)
ratio (in percent) of the maximum breadth to the maximum length of a skull	ratio (in percent) of the maximum breadth to the maximum length of a skull