while the maxilla/palate is the roof of your mouth, you can also think of it as the floor of your nose; so you can understand how expansion might affect the nose 

you've likely noticed improved nasal breathing too

I have noticed improved nasal breathing, especially on the left side (which is the side that was always more restricted)

What made me hesitate to believe that my changes are skeletal is my age (43) and I'm not doing SARPE, MSE, or anything else like that.

I'm probably a rare case, because I DID undergo a segmented LeFort 1 osteotomy when I was 19, which probably left the bone rather thin in the palate even after all these years.

My doctor at the time also remarked about my exceptionally thin bones.  He later said the iliac crest was way too thin and so, when I woke up from the operation, I found that he had no choice but to harvest bone from the upper side of my skull, and even that was rather thin.

Despite the operation, I've still had a class 3 bite since then albeit not as bad (partially because he was limited in how much grafting he could do, and partially due to some relapse).  After being dissatisfied all these years, I began with the expander and mewing last December.  That leads me to where I am today.

I should also add that I did develop a midline diastema a couple weeks in, but it never reached more than a millimeter.  Over time, other smaller diastemas have opened on either side of the canine teeth.  You can't really see them in this picture (but you can see the midline).

Here is a picture of what my nose and anterior teeth look like now.  You can also see a lot of asymmetry.

Posted by: @mr_man

You can also see a lot of asymmetry

Was the assymtery always present ?

@dragonshark

Yes, but to a smaller degree.  It got worse after the lefort procedure (at age 19)