So called "6 month braces" turned into 7 months due to the lack of skill involved to correct the position of one of my bottom teeth, that shifted while wearing the braces; and had no issues prior to getting the braces. My simple case, having 6mm of space closed on the top, and could have been completed in 5 months (which I was told more than once); is still not completed.
It has taken two weeks to get an aligner constructed, and it has not not been completed and placed. I'm still wearing braces after 7 months.