It seems like Dr. Teeth rarely interacts with characters outside of The Electric Mayhem (and even then, he rarely directly interacts with Janice... or Lips). He interacted with Sam the Eagle in the "Mack the Knife" number, and with Beaker in Rock Music with the Muppets... And while both were only one-time team-ups, they seemed like natural pairings. Oh yeah and he's danced with Mildred twice (and they don't really seem like each other's type).