I have three different editions of Burns's more mainstream collected works and (slight) differences can be found in some of the pieces, reflecting the fact that they were originally handwritten by Burns at different times.

My copy of "The Merry Muses" has "wrinkles", which IMHO makes a little more sense, without going into anatomical detail. I have a recording of the fine singer Gordeanna McCulloch, who used "wrinkles", but there are a few minor variations in her version from both the above and my printed text.