hypoplasia vs dysplasia

hypoplasia and dysplasia both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypoplasia	Yes	No	No	No
dysplasia	Yes	No	No	No

As nouns, dysplasia is a hypernym of hypoplasia; that is, dysplasia is a word with a broader meaning than hypoplasia:

hypoplasia: underdevelopment of an organ because of a decrease in the number of cells
dysplasia: abnormal development (of organs or cells) or an abnormal structure resulting from such growth

hypoplasia (noun)	dysplasia (noun)
underdevelopment of an organ because of a decrease in the number of cells	abnormal development (of organs or cells) or an abnormal structure resulting from such growth