| 'Juvenile' isn't a term that's really used anymore. It's how people used to refer to T1, because T1 tends to be manifest itself in juveniles rather than adults.
Basically, all the old ways of determining which type of diabetes you have are wrong. They're predicated on either age or treatment - neither of which are an indicator of your condition.
If you don't produce any insulin at all because of an autoimmune reaction that destroyed your islet cells, then you're a T1, regardless of age of diagnosis. If you do produce insulin but you aren't able to use it, or you just don't produce enough insulin, then you're a T2, regardless of age of diagnosis.
Generally T1 manifests itself before age 14 and and T2 after age 40, which is why T1 used to be called juvenile-onset and T2 mature-onset. But these aren't set in stone.
If you don't produce any insulin because you've had an autoimmune reaction that's killed off your islet cells, you're a T1. | 
