"Maintenance" courses are actually quite rare, since most people don't need to go beyond 2-3 courses anyway--I mean, if your acne returns and can't be managed with topicals, they'll put you on another course, sure. That's how it usually goes.
I've heard of those with extremely oily skin go through (intermittent) low-dose courses, as well as some very severe acne-like conditions. Like I said before, the (intermittent) low-dose maintenance courses are being studied right now with patients having anywhere from mild to severe acne.
Like this one: http://www.ncbi.nlm....pubmed/17710426 <--this one has full text available, if you want to read it.
It requires more study, of course, but it looks really promising!
Edit: Yay for your scar improvement!
Edited by Michelle Reece, 15 February 2014 - 08:32 PM.