To add on to what the others have said, if you dog is 90 lbs at 10 months -- as you mentioned in your intro -- he is not likely to be a purebred American Pit Bull Terrier. He could possibly be an American Bully, or have some kind of bigger dog influence behind him. The APBT
standard reads 30-60 lbs (UKC).
As others have stated, without looking at a pedigree, we couldn't tell you what your dog is. Pit mix, BBM (bully breed mix), pick your poison.