hi anonymous; this answer might be a little disappointing, but i just do-not have much of an opinion on either -- i think sometimes (from like an appeal standpoint) stuff like crooked or missing teeth can be cute as a contrast to the ordinary, but otherwise i just see all of it as "mouth." there was a book i read in HS by chuck palahniuk (sp?) about a character who encased his teeth in tar, though, and i thought that was neat.
teeth, over-all, if i am talking to someone face-to-face, are what i stare at most often -- not really out of interest, but because i want to see what shape they are in (gum-line and stuff, because i compare it to my own), and i don:t want to look at their eyes.