Nancy, a loyal client from Indiana requested a caricature of her dentist, Dr Tyree, who specializes in child care.  Apparently he works on adults as well, but I'm assuming don't get the same benefits, as  Nancy mentioned her jealousy of all the kids who get nitrous oxide to calm them as they get their teeth worked on (hence the contraption over the nose) while Disney's 'Cars' plays in the background.  She wanted those elements depicted in the caricature, and of course, the requisite toothbrush also makes it's appearance, which must always be happy and showing off perfect teeth!