Helen darling, I think you got Jan-Michael Gambill and Jan-Michael Vincent mixed up.
Jan-Michael Gambill is the professional tennis player. Jan-Michael Vincent is the toothless actor you saw in the Enquirer. I don't think he was on Miami Vice. The three-named-actor on that show was Philip Michael Thomas.
Anyhoo, I hope "Granny 5" will get a DVD release in time for Christmas. (I'm assuming it goes straight-to-DVD). It will make a great stocking stuffer!