10 inches is a pretty good size juvie...not full grown yet.
mines almost 2 years old and 9 inches...so, yours might be a little over 2.
i don't think the spines have much to do with age (i might be wrong) also...i'm not sure if its very reliable cuz mines spikes are smaller at the tail base too. i think all are inless they've had tail rot...then they don't have any spikes 
heres a picture of vlad.

hope this was some help.
trevor
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Posted by: harberrat at Sat Mar 27 21:34:56 2004 [ Report Abuse ] [ Email Message ]
i'm not sure how old he is. i'm figuring appx. 2yrs, is that considered a juvie? hes about 10 inches and 200g. i was holding him today and checking out his spikes. i was thinking that determining age could be done by the size/sharpness of the spikes as the spikes at the base of the tail are smaller and less sharp, is this a concept worth some thought? as far as petting i do stroke his cheeks and chin but he is so alert that he would never close his eyes. thanks for your reply. laura
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Trevor Bennett
E-mail: yruemailinme15@yahoo.com
yahoo SN: yruemailinme15
location: Salem, Oregon