baby face vs mien

baby face

noun
  • A face, often chubby, resembling that of a baby; a youthful face. 

  • A person having such a face, especially a young man having a beardless appearance. 

  • A headlining wrestler with a persona embodying heroic or virtuous traits and who is regarded as a "good guy", especially one who is handsome and well-conditioned. 

mien

noun
  • A specific facial expression. 

  • Demeanor; facial expression or attitude, especially one which is intended by its bearer. 

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