bicuspid vs premolar

bicuspid

noun
  • A tooth with two cusps; a premolar tooth. 

adj
  • Having two points or prominences; ending in two points; said of teeth, leaves, fruit, etc. 

premolar

noun
  • A tooth situated in front of the molar teeth; especially a tooth in humans with two cusps which is between the canines and the molars (Latin: singular dens premolaris, plural dentes premolares) 

adj
  • Before a molar tooth, either in physical position or in its time of development; deciduous. 

How often have the words bicuspid and premolar occurred in a corpus of books? (source: Google Ngram Viewer )