What questions should I ask about private orthodontist quote?

[MrsFogi]

Dd needs a brace etc and we could wait 18 months or go private. I have put her on the waiting list but have also got a quote in case we decide to get her teeth done privately now. Can anyone suggest any questions I should raise before signing up to private treatment (so far I think I need to ask about whether or not the retainer is included (I suspect not), whether breakages are charged extra).
Also is there ever any room for negotiation on the quote?

[MrsFogi]

Has no one asked any questions (or wished they did) ? thanks

[whodoesntloveafluffycat]

DS had his on the NHS. I wish I'd know how often he had to attend for follow up and whether appointments were available after school.
I suppose you could also check that all the treatment including X-rays is included in the quote.