front tooth vs anterior

front tooth and anterior both are nouns.

Word	Noun	Adjective	Verb	Adverb
front tooth	Yes	No	No	No
anterior	Yes	Yes	No	No

As nouns, front tooth and anterior are synonyms defined as:

front tooth (noun)	anterior (noun)
a tooth situated at the front of the mouth	a tooth situated at the front of the mouth

front tooth (adjective)	anterior (adjective)
	of or near the head end or toward the front plane of a body
	earlier in time