All the riddles + Riddler trophies + chronicles of Arkham + patient interview tapes in "Caves" area can be found in this special video guide. All the Joker teeth can be found in my other walkthrough videos for the full storyline. My advice, collect stuff and solve the riddles after the whole storyline is passed (defeat Joker) and all the gadgets are upgraded. Impossible to reach some trophies without unique/improved gadgets.