I had a RPE for seven months. It was supposed to be for 5 months, but there was a wait for appointments so it was in longer...oh well...it had stopped doing it's job by then and I was already in braces so it wasn't doing anything either than bugging me.
I never noticed any spacing between my teeth. The only way I knew it was working was that I could feel the gap between the plastic on the roof of my mouth. When it was put in, there wasn't anything and by the time it came out, I had about 5mm of space between the two pieces. It ached every so often so I'd push up on it with my tongue...yk, like counterpressure...and it helped for a short time. It did its work.
Upper and Lower expander - August 2008
Damon braces - February 19, 2009
Expanders removed - April 2, 2009(Thank GOD!)
Braced for 18 months...but only had them for 14 months!
Braces removed - April 12th, 2010