bicuspidate vs premolar

bicuspidate

adj
  • Having two points or prominences (as teeth, leaves, fruit, etc.); bicuspid. 

premolar

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

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) 

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