The Smithsonian often plays a small role on the small screen, and those references are revealing about popular stereotypes of the Smithsonian. For many TV series, the standard destination for something old and dilapidated is, of course, the Smithsonian.
1 The part of the tooth that is visible in the mouth, above the gum line on lower teeth and below the gum line on upper teeth, is called the clinical crown.  A cemented restoration that partially or completely covers the outside of the clinical crown is referred to as a dental crown or cap.
The crown is the part that fits over your head. Crowns come in various heights, depending on style. The brim is the edge of the hat that the crown is attached to. At the bottom of the crown is typically a band that secures the hat on your head. The crown can be pushed in at several different places for variation.