I believe that there may be no special word for those terms. Here are some things I found:
In the Nova Vulgata, Leviticus 20:20 reads:
Qui coierit cum uxore patrui vel avunculi sui...
"Whoever has intercourse with their own (paternal or maternal) uncle's wife..." Here we have patrui vel avunculi referring to both maternal and paternal uncles. It's important to note that the Nova Vulgata is written in Latin more similar to Classical Latin than the original Vulgate, so it holds some credibility.
I also found in Catullus's Carmina:
Patrui perdepsuit ipsam uxorem...
"He kneaded his uncle's very wife..." Catullus was, of course, a Classical Latin speaker. That being said, he then goes on to mention "ipsum... patruum", so there is a slight chance that he is saying this because he references the uncle later.
I cannot find many examples for aunt, but I think they're out there.
Personally, I find it rather sensible that only paternal and maternal aunts or uncles have terms. The rest are not blood relatives, so they have no affect on your relations to your blood relatives.