upper jawbone vs maxilla

upper jawbone and maxilla both are nouns.

Word	Noun	Adjective	Verb	Adverb
upper jawbone	Yes	No	No	No
maxilla	Yes	No	No	No

As nouns, upper jawbone and maxilla are synonyms defined as:

upper jawbone and maxilla: the jaw in vertebrates that is fused to the cranium

Other synonyms of upper jawbone include maxillary, upper jaw.

upper jawbone (noun)	maxilla (noun)
the jaw in vertebrates that is fused to the cranium	the jaw in vertebrates that is fused to the cranium