denticle vs gnasher

denticle

noun
  • A dentil. 

  • A pulp stone. 

  • Material serving as the dermis of sharks. 

  • A small tooth. 

gnasher

noun
  • A tooth. 

  • One who gnashes the teeth. 

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