jawline vs mentum

jawline

noun
  • The lower edge of the side of the face (below the cheek), defined by the jawbone. 

mentum

noun
  • The chin. 

  • The central part of the labium in insects. 

  • A chin-like projection below the mouth of certain mollusks. 

  • A projection in front of the flower in some orchids. 

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