scritch vs set someone's teeth on edge

scritch

verb
  • To scratch so as to relieve an itch or irritation. 

  • To make a light scratching sound, like a small animal burrowing. 

noun
  • The act of scratching an itch. 

  • A light scratching sound, like a small animal burrowing. 

set someone's teeth on edge

verb
  • To irritate or strike as unpleasant. 

  • To cause a disagreeable tingling sensation in one's teeth, as when acids are brought into contact with them. 

How often have the words scritch and set someone's teeth on edge occurred in a corpus of books? (source: Google Ngram Viewer )