retroversion vs retrogression

retroversion and retrogression both are nouns.

Word	Noun	Adjective	Verb	Adverb
retroversion	Yes	No	No	No
retrogression	Yes	No	No	No

As nouns, retroversion and retrogression are synonyms defined as:

Other synonyms of retroversion include regress, regression, reversion.

retroversion (noun)	retrogression (noun)
returning to a former state	returning to a former state
translation back into the original language	passing from a more complex to a simpler biological form
a turning or tilting backward of an organ or body part